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Volume 11 • Issue R8 FACIAL FRACTURES Shai Rozen, MD, FACS Reconstructive www.SRPS.org Editor-in-Chief Jeffrey M. Kenkel, MD Editor Emeritus F. E. Barton, Jr, MD Contributing Editors R. S. Ambay, MD R. G. Anderson, MD S. J. Beran, MD S. M. Bidic, MD G. Broughton II, MD, PhD J. L. Burns, MD J. J. Cheng, MD C. P. Clark III, MD D. L. Gonyon, Jr, MD A. A. Gosman, MD K. A. Gutowski, MD J. R. Griffin, MD R. Y. Ha, MD F. Hackney, MD, DDS L. H. Hollier, MD R. E. Hoxworth, MD J. E. Janis, MD R. K. Khosla, MD J. E. Leedy, MD J. A. Lemmon, MD A. H. Lipschitz, MD R. A. Meade, MD D. L. Mount, MD J. C. O’Brien, MD J. K. Potter, MD, DDS R. J. Rohrich, MD M. Saint-Cyr, MD M. Schaverien, MRCS M. C. Snyder, MD M. Swelstad, MD A. P. Trussler, MD R. I. S. Zbar, MD Senior Manuscript Editor Dori Kelly Business Manager Becky Sheldon Corporate Sponsorship Barbara Williams 30 Topics Grafts and Flaps Wound Healing, Scars, and Burns Skin Tumors: Basal Cell Carcinoma, Squamous Cell Carcinoma, and Melanoma Implantation and Local Anesthetics Head and Neck Tumors and Reconstruction Microsurgery and Lower Extremity Reconstruction Nasal and Eyelid Reconstruction Lip, Cheek, and Scalp Reconstruction Ear Reconstruction and Otoplasty Facial Fractures Blepharoplasty and Brow Lift Rhinoplasty Rhytidectomy Injectables Lasers Facial Nerve Disorders Cleft Lip and Palate and Velopharyngeal Insufficiency Craniofacial I: Cephalometrics and Orthognathic Surgery Craniofacial II: Syndromes and Surgery Vascular Anomalies Breast Augmentation Breast Reduction and Mastopexy Breast Reconstruction Body Contouring and Liposuction Trunk Reconstruction Hand: Soft Tissues Hand: Peripheral Nerves Hand: Flexor Tendons Hand: Extensor Tendons Hand: Fractures and Dislocations, the Wrist, and Congenital Anomalies Selected Readings in Plastic Surgery (ISSN 0739-5523) is a series of monographs published by Selected Readings in Plastic Surgery, Inc. For subscription information, please visit our web site: www.SRPS.org. This blank page is included for proper presentation in two-page view. SRPS • Volume 11 • Issue R8 • 2015 FACIAL FRACTURES Shai Rozen, MD, FACS University of Texas Souithwestern Medical Center at Dallas, Dallas, Texas INTRODUCTION In the recent decade, we have seen tremendous innovation in the area of facial reconstruction. A new era of facial transplantation has commenced, and we are making slow but steady progress in the science of tissue engineering. Both fields will enable us to achieve optimal reconstructive and aesthetic results that we have not seen before with traditional reconstructive techniques. However, formidable barriers lie ahead before we can fully apply these in the daily clinical work for treating patients with facial injuries. Regardless of what future lies ahead, the basis for treatment of all compound facial injuries involving both the bony frame and the softtissue envelope remain the same: perfect recreation of the bony framework to its premorbid position avoiding late irreversible sequelae of malpositioned concentric healing of the soft tissue. The tenets of bony reconstruction of the face are early intervention, wide exposure of the facial skeleton, anatomic reduction, internal fixation, and primary bone grafting. Non-adherence to these basic rules will result in nearly irreversible facial deformity caused by the insurmountable strength of the concentric soft-tissue scarring, which occurs early after the injury. Early intervention is key, and situations in which it is contraindicated are rare. The goal of this monograph is to provide not only a list of references of the current literature on the subject but also to afford the reader a readable and comprehensive overlook on the subject that will hopefully intrigue the reader to further in-depth reading. PRINCIPLES OF OPEN REDUCTION AND INTERNAL FIXATION Fracture Environment The facial skeleton provides protection of vital soft organs, a rigid frame for masticatory and facial muscle function, and support of the overlying soft tissue. Therefore, restoration of bony anatomy should satisfy two major goals: optimal function and normal appearance. To provide optimal function, adequate anatomic shape and stiffness (resistance to deformation under load) are basic requirements. Fractures result from mechanical overload that most commonly occurs in milliseconds when facial fractures are concerned. The fracture not only directly interrupts the structural integrity and stiffness of the bone but also disrupts the internal blood supply of the bone. External blood supply is further disrupted by implosion, which is a unique phenomenon seen in facial trauma that occurs immediately after the fracture. It involves marked soft-tissue damage caused by cavitation. Therefore, in addition to intracortical blood vessel disruption, surrounding soft tissue vascular damage also occurs, thereby further decreasing the blood supply to the bony fragments. Yet experience in craniofacial surgery, namely the midface and cranial region where the bony walls are thin, shows that even bony fragments that are stripped from their surrounding soft tissue regain circulation rapidly. Thus, infections are minimal and healing is generally good. The mandible, on the other hand, is to some extent comparable to long bones because of its cortical thickness. Therefore, delay in healing is expected until intracortical circulation is restored. 1 SRPS • Volume 11 • Issue R8 • 2015 Clinical healing is reached when the bony structures can resume their full function. For optimal bone healing to occur, both biological and mechanical conditions have to be met. For optimal biological conditions to occur, blood supply to the fragments is a prerequisite and surgical and plating techniques therefore strive to minimize devascularization of bone segments. Optimal mechanical conditions around the fracture will also affect bone-healing patterns. On the one extreme, when absolute immobilization occurs, optimal conditions are created for formation of bone. In this case, osteoclasts can drill their canals across the immobilized contact zone and newly formed osteons link the fragments together. This process is called direct or primary bone union. On the other end of the healing spectrum, high interfragmentary motion occurs. Under this mechanical situation, the strain in the fracture gap exceeds the level tolerated by bone and ossification is not possible. In this scenario, a tissuedifferentiation cascade occurs and granulation tissue turns into connective tissue, fibrocartilage, mineralized cartilage, woven bone, and finally compact bone (Fig. 1).1 In most fractures, various degrees of immobilization occur and different patterns of bone healing might therefore be seen in one fracture. Experience shows that remodeling of the mandible to full load bearing and removal of the plate requires 4 to 6 months versus 1.5 years in the tibia and 2 years in the fibula. However, in the midfacial and cranial regions, bony fixation can occur after 1 month because of the excellent blood supply in that region of the body. The same rules apply to bone grafts, which similarly heal very quickly.1 Potential complications of bone healing include infection, refracture, delayed healing, nonunion, implant loosening, and implant failure. Refracture is a rare occurrence in the cranio-maxillofacial region because of the rapid healing that occurs in that region. Therefore, surgical refracturing (i.e., osteotomy) is needed in cases in which reduction was not properly performed. Infections are not common. They sometimes occur in cases of severe soft-tissue injury when surrounding blood supply has been severely compromised. Mere exposure of fixation devices caused by skin or mucosal laceration does not mean that deep infection will ensue. Healing is considered delayed when union takes longer than expected (longer than 4−6 weeks in the midface and longer than 12 weeks in the mandible) 2 (Fig. 2).1 If nonunion is observed, resection is not necessary. The problem is excessive mobility and strain at the fracture sight, which prevents the mineralization of the moving fracture gap. Use of a stiffer and stronger implant, such as a reconstruction plate, will allow further differentiation leading finally to compact bone. Loose screws, insufficient number of screws, and undue functional loading can all cause implant failure. Indications for Operative Treatment of Fractures Whether treating craniofacial trauma or performing osteotomies for correction of craniofacial deformities, the goals of surgery are expedient recovery of form and function. Optimal, not maximal, stability is required. Under these conditions, undisturbed healing occurs. It is important that the surgeon performing internal fixation understands the principals of conservative treatment first. Closed, simple, non-displaced fractures can be treated by conservative methods, namely inter-maxillary fixation for several weeks in cases of maxillary or mandibular fractures. Functionally stable internal fixation is indicated for the following fractures: •• Multiple or comminuted fractures of the mandible or maxilla •• Panfacial fractures •• Defect fractures •• Open fractures •• Dislocated fractures •• Fractures of the atrophic mandible in the geriatric patients •• Infected fractures of the mandible Additional absolute indications for internal fixation are inability and unwillingness of the patient to cooperate. Early definitive care is also indicated for patients with multiple traumatic injuries. All fractures should be treated simultaneously, and swelling should not delay facial fracture repair. Adequate stabilization is more important than antibiotics for protection against infections and is key in preventing concentric scarring and collapse of the softtissue envelope. The general goals of surgery are early anatomic SRPS • Volume 11 • Issue R8 • 2015 A B C D Figure 1. High interfragmentary motion is a mechanical situation in which the strain in the fracture gap exceeds the level tolerated by bone. A tissue-differentiation cascade occurs, and granulation tissue turns into connective tissue, fibrocartilage, mineralized cartilage, woven bone, and finally compact bone (Modified from Prein and Rahn.1) 3 SRPS • Volume 11 • Issue R8 • 2015 Implant Materials Stiffness of fracture Normal Delayed union Nonunion 2 4 6 8 Healing time 10 weeks Figure 2. Line graph depicts fracture healing and recovery of mechanical function. Initially, a healing fracture presents with low strength and low stiffness. Four to 6 weeks later, a notable change in mechanical properties occurs. At that time, in an undisturbed situation, mineralization across the fracture plane takes place. If the loading of the mineralizing fracture does not exceed certain limits, healing proceeds normally. Undue loading of such a uniting fracture at a critical moment can disturb the mineralization process and lead to delayed union or nonunion. (Modified from Prein and Rahn.1) reduction of the fracture fragments, maintaining their position after reduction, and achieving union in the desired position. To achieve these goals, the plates used for fixation must act directly at the fracture site and neutralize the loads occurring under daily function at that specific site. Considerations such as personality and compliance of a patient, type and site of the fracture, and condition of the overlying tissue can affect the selection of the appropriate implant. The role of the implant is to share the load of the fracture site until bone regeneration takes over the load. Both compressive and tensile forces can occur over fracture sites. Often, the bone can tolerate the compressive forces across the fracture site thereby allowing use of much smaller implants to share the tensile forces occurring over the fracture. Still, underestimation of the forces crossing the fracture site might lead to choosing plates of insufficient size, culminating in early fracture of the plate caused by fatigue failure. 4 The ideal implant material needs to be strong and ductile, inert, biocompatible, and adaptable to fit bone. Until 1986, stainless steel was the metal of choice. Today, however, commercially pure titanium is the material of choice for craniofacial reconstruction. Titanium has a high corrosion resistance because of the spontaneously forming thin oxide layer on the surface, which assures that the material will behave passively. Considering the inertness of titanium and the involvement of multiple screws and plates in most cranio-maxillofacial operations, removal of the screws and plates is not indicated because of a small but present risk of injury to structures during removal and the additional risks inherent with any anesthesia. Indications for implant removal include a general feeling of disturbance caused by chronic infection or allergic reaction. Aesthetic considerations, such as a shiny appearance of the plate under thin skin, sensitivity caused by changes in temperature, and problems with dentures, can constitute additional indications for removal. It is important to understand that infection in the presence of an implant is not always an indication for implant removal. If fixation is stable, the implant can be left until complete stabilization occurs. Stabilization is the most important way to treat infection. If the fixation is unstable, plate removal and re-stabilization are mandatory. The use of non-absorbable plates in the pediatric population is controversial. Removal of the plates usually is indicated not because of risk of growth retardation but rather because of possible intracranial translation by drift phenomena. Plates and Screws The use of specific types of plates and screws, such as compression plates and screws, is noted in different sections of the text. For a full description of the different types of plates and screws, the reader is encouraged to read the first chapter in the Manual of Internal Fixation in the Cranio-Facial Skeleton.1 SRPS • Volume 11 • Issue R8 • 2015 GENERAL CONSIDERATIONS IN THE TREATMENT OF FACIAL FRACTURES Mechanism of Craniofacial Injuries and Associated Injuries The mechanisms of craniofacial trauma in the United States include motor vehicle collisions, altercations, assaults, home and industrial accidents, and athletic injuries. A review of 7296 patients treated during an 11year period at The University of Maryland Shock Trauma Center showed that motor vehicle collisions were the most common mechanism of injury.2 The frequency of severe facial trauma resulting from motor vehicle collisions in the 1970s and 1980s has significantly decreased because of increased use of seat belts, air bags, and strict enforcement of laws against speeding and drunk driving. Lee et al.3 presented a comprehensive review and analysis of approximately 7300 patients admitted for craniofacial trauma between the years 1983 and 1994. The average patient age in that study was 33 years, and the ratio of male predominance was 2:1. Motor vehicle collision was the most common mechanism of injury. Overall mortality was 5.9% but increased to 17% when the craniofacial trauma was associated with brain injury. The midface was the facial region most susceptible to fracture.3 Concomitant Injuries Concomitant injuries are common in patients with facial injury. Lim et al.4 showed in a population of 839 patients with facial trauma that 11% sustained injuries outside the facial skeleton, 8% had injuries of the extremities, 5% had associated neurological injuries, 4% ocular injuries, and 1% spinal injuries. Injuries of the head, neck, and spine occur in more than 50% of patients involved in motor vehicle collisions. Because of the prevalence of associated injuries, it is vital that a full and thorough multi-system evaluation be conducted, including the airway, central nervous system, and hemodynamic stability, before treating the face. Patients with multiple traumatic injuries should not be transferred to subspecialty services before complete evaluation, yet treatment should be expeditious once patient stability is obtained.5,6 Airway Management Of cardinal importance in a patient with facial trauma is the management of the airway. Many patients with facial trauma do not require emergent intubation. The type of elective intubation depends on the type of fracture and surgical approach for repair. Patients who are most proned for asphyxiation as a result of the trauma are those with the following injuries: 1)Severely comminuted mandibular fracture 2)Combined mandibular fracture with midfacial fractures 3)Pan-facial fractures 4)Associated brain injuries Patients suffering from severe mandibular fractures might lose anterior support of the tongue with resultant movement of the tongue toward the posterior pharynx and blockage of the airway. Simple maneuvers as anterior retraction of the mandible, direct traction on the tongue, and clearance of the oral cavity from any loose content might suffice until elective airway control is obtained. In the rare emergent situations, a cricothyroidotomy or coniotomy is performed.7 This emergent procedure should be converted to a tracheostomy as soon as possible to avoid complications associated with long-term cricoid intubation.8,9 Elective tracheostomy should be performed in cases in which an oral tube would disrupt surgery and in patients who would not be able to manage their airways in a week’s time, as in some patients with panfacial trauma, head injuries, or chest injuries. A summary of guidelines for emergent tracheal intubation and tracheostomy is presented in an article by Dunham et al.10 The type of elective intubation should be decided based on the type of trauma and whether maxillary mandibular fixation (MMF) is necessary for fracture treatment. Most fractures involving the frontal region, orbit, zygoma, or nose do not require MMF, and oral intubation is the preferred route of intubation. In cases in which MMF is necessary, such as fracture of the mandible and maxilla or any situation in which occlusion has been disrupted, a nasal tube is the preferred route of intubation. This should be performed with nasoendoscopy if a skull base fracture is suspected to avoid inadvertent passage of the tube into the cranium. Oral intubation can also be performed in these cases if it is possible to place the tube 5 SRPS • Volume 11 • Issue R8 • 2015 in teeth gaps or behind the molars. Another form of oral intubation is the transoral approach in which the tube is delivered via an incision through the floor of the mouth exiting the submental area. The major disadvantage of this route is the difficulty to re-intubate emergently if needed. Blood Loss Life-threatening hemorrhage occurs in 1.2% to 5% of midface fractures.11,12 Seventy percent of them originate from the internal maxillary artery or its branches. In cases of superficial bleeding, direct pressure, packing, or ligation generally suffices. Temporary reduction of fractures manually or direct approximation of wounds by suturing might help control bleeding until definitive care is provided. Anterior nasal bleeding can effectively be controlled by nasal packing, which can be removed after a 2- to 3-day period (Fig. 3).13 Bleeding from the nasopharyngeal region is more difficult to control.14−16 The source of bleeding usually is the posteriorly located internal maxillary artery. Passing two Foley catheters, one through each nostril, into the pharynx and inflating them 30 to 50 mL each can help achieve rapid control of bleeding. The balloons are then pulled into the posterior nasopharynx and provide a posterior obturator against which several packs of antibiotic impregnated petrolatum gauze are inserted into each nasal cavity. The packing provides compression, and the apparatus can be secured by tying the foley catheters together over the columella. Necroses of the columella, palate, and nose sometimes occur. Relieving the pressure every couple of hours and a trial of balloon deflation after an hour might decrease these complications. The packing can be removed in 24 to 48 hours. Blindness is a potential associated complication, and care should be taken when severe comminuted fractures occur to avoid intracranial insertion of the catheters. Manual reduction and intermaxillary fixation (IMF) can substantially reduce bleeding of midface fractures (Fig. 4).13 In cases in which persistent bleeding occurs, selective arterial embolization is warranted.12,17,18 During the whole period in which hemorrhage control is attempted, coagulation function should be assessed and corrected as needed. In cases in which all attempts have failed, selective arterial ligation, including bilateral external 6 carotid arteries and temporal arteries, might decrease blood flow in the midface and decrease bleeding. Head Injury All patients with head injuries should undergo thorough clinical evaluation and classified by severity of injury based on the Glasgow Coma Scale (GCS) (Table 1). Motor score alone might be a good predictor of survival,19 and pupil size and reactivity are good predictors.20 Patients with a GCS score of 3 and fixed dilated pupils have nearly no chance of survival.21−25 A computed tomographic (CT) scan of the brain, skull, and face is essential for all facial trauma patients. Any patient with head injury associated with advanced age, decreased GCS score, hypotension, abnormal posturing, prolonged intracranial hypertension, or additional associated injuries such as spinal injury, lung injury, or shock have a worse prognosis. Children, in general, have a better prognosis. Presence of coma alone should never delay nor contraindicate the treatment of facial trauma. Neurosurgical research has shown that nearly half the patients who suffered from coma that lasted more than 1 week returned to useful work.26 Therefore patients who survive severe head injury greatly benefit from timely intervention of their facial trauma. Eighty percent of patients who suffer from coma of less than 20 minutes experience late symptoms, such as headaches, decreased attention span, poor concentration, and behavioral alterations.27 These patients might benefit from intervention at a head injury rehabilitation center.26 Cervical Spine Injuries Significant cervical spine injury is reported to occur in one of 300 patients involved in accidents and in one of 14 of patients who have been ejected from motor vehicles.28,29 Patients who are unable to move their extremities on command or with sternal pressure, those with penetrating injuries to the neck, and those who complain of cervical pain or have decreased sensation or motor deficits should be considered to have cervical spine injuries until proven otherwise. Larger studies suggest that 10% of patients with facial fractures have cervical spine injury and that 18% of patients with cervical spine injury have maxillofacial injury.30,31 Mandible fractures are associated with high SRPS • Volume 11 • Issue R8 • 2015 Vertical strips Catheter Horizontal strips Post-nasal pack Post-nasal pack Figure 3. Illustration shows the technique of anterior-posterior nasal packing to stop severe nasopharyngeal bleeding. A, A posterior pack is guided into the nasopharynx by a suture attached to a Foley catheter. Alternatively, a Foley catheter can have its balloon inflated in the posterior pharynx and brought to the posterior choanal nasal opening. B, With either a posterior nasal pack or a Foley catheter balloon in place, the nasal cavity is packed with strips of antibiotic ointment-impregnated gauze. The entire cavity of the nose should be thoroughly packed and light pressure applied. If bleeding persists, the anterior pack should be removed and the recesses of the nasal cavity carefully repacked. With severe fractures, care should be taken not to enter the anterior cranial fossa or the orbit through areas of disrupted bone. (Modified from Mathes.13) 3 4 2 1 4 Figure 4. If nasal packing does not suffice to control bleeding, a Barton bandage can be used but is of limited usefulness. Placement of the patient in intermaxillary fixation, however, is extraordinarily effective in cases of Le Fort fracture bleeding. Selective angiography with embolization is the procedure of choice for persistent bleeding. If selective embolization by angiography fails, application of external pressure and ligation of the superficial temporal and external carotid arteries are performed. Selective arterial embolization requires angiographic clarification of the bleeding point. (Modified from Mathes.13) 7 SRPS • Volume 11 • Issue R8 • 2015 Table 1 Glasgow Coma Scale Response Eye opening Verbal Motor Scale Score Spontaneous, open with blinking at baseline 4 Opens to verbal command, speech, or shout 3 Opens to pain not applied to face 2 None 1 Oriented 5 Confused conversation but able to answer questions 4 Inappropriate responses, words discernible 3 Incomprehensible speed 2 None 1 Obeys commands for movement 6 Purposeful movement to painful stimulus 5 Withdraws from pain 4 Abnormal (spastic) flexion, decorticate posture 3 Extensor (rigid) response, decerebrate posture 2 None 1 cervical spine injuries, and upper facial injuries are associated with hyperextension injuries of the cervical spine at all levels. 1)High clinical level of suspicion The most commonly missed lesions are lower and higher cord injuries: C1−C2 and C6−C7 cord injuries.28,29,32−36 CT scans and magnetic resonance images (MRI) are the imaging studies of choice if spinal injury is suspected. Harris37 noted that cervical spine injuries are missed in 10% of patients and that approximately 50% are mismanaged. He recommended the following: 3)Full neurologic examination 8 2)Protection of the spine 4)Use of consultants 5)CT scans or MRI in addition to plain film radiographs and when neurological examination is abnormal SRPS • Volume 11 • Issue R8 • 2015 Timing of Surgical Treatment Mechanism The timing of surgery in patients with facial injuries is important for obtaining optimal results.25 In general, treatment of facial injuries does not require emergent surgical care. Reduction of fractures or closure of wounds is not an emergency. Still the need for expedient care cannot be overemphasized. Earlier intervention decreases disfigurement and improves functional outcome.38,39 Bones are more easily placed in their anatomic positions and less extensive soft-tissue stripping is necessary. Frontal sinus fractures usually are caused by direct impact. The frontal sinus is involved in 2% to 12% of all cranial fractures.41 Approximately one-third of frontal sinus fractures involve the anterior table, 60% involve the anterior and posterior tables and the nasofrontal ducts, and the remaining involve the posterior table alone. Dural laceration accompanies 60% of all frontal sinus fractures. If the frontal sinus is well pneumatized, the majority of the energy is absorbed and the posterior table usually is uninvolved. If the frontal sinus is not well developed or high-energy impact is involved, the posterior table usually is involved and the risk of dural and intracranial involvement is increased.42 Exceptions to immediate intervention include the following: 1)Patients with ongoing bleeding and hemodynamic instability 2)Patients with continuous intracranial hypertension 3)Coagulation problems 4)Abnormal pulmonary ventilation pressures These patients might not tolerate surgery, but open wounds can be closed at the time of admission, MMF can be applied, and gross reduction of fractures can be performed. On the other hand, patients with head injuries or multi-system trauma should not be delayed from treatment simply based on those injuries.40 FACIAL FRACTURES BY ANATOMIC REGION Frontal Sinus Fractures Anatomy The frontal sinuses are paired structures above the orbital rims that have only ethmoidal anlages at birth. These sinuses start pneumatization at the age of 3 years, but substantial pneumatic expansion begins at the age of 7 years. The frontal sinus achieves full size at approximately age 18 to 20 years. The sinus has two tables: an anterior and a posterior table.41 In between, the sinuses are lined with respiratory epithelium consisting of ciliated membranes, which direct the mucin toward the nasofrontal duct, located in the inferior medial aspect of the sinus. The exact function of the sinuses is not clear, but when developed, they might absorb the energy created by a trauma, thus protecting the intracranial content. Diagnosis The typical physical signs found in patients with frontal sinus fractures include lacerations, bruises, and hematomas of the periorbital and forehead regions. Anesthesia in the supraorbital nerve distribution can occur, and cerebrospinal fluid (CSF) rhinorrhea might be observed. Subconjunctival or periorbital ecchymosis occasionally occurs. In some patients, depression of the forehead is seen. More often, swelling obscures the depression in the acute setting. Existence of any of these signs must raise suspicion of fractures. CT scanning is the imaging modality of choice. Findings can include fractures, orbital or intracranial air, and air fluid levels in the sinus suggesting frontal duct occlusion, especially if persistent. Small fractures can be difficult to detect, even on CT scans, and a frontal sinus fracture occasionally presents as a frontal sinus infection, mucocele, or abscess formation secondary to nasofrontal duct occlusion.43−45 Treatment The type of fracture dictates the type of treatment for frontal sinus fractures, but uniformity in treatment strategies does not exist. Classification systems attempt to divide frontal sinus fractures into the following categories: •• Anterior table, displaced or non-displaced •• Posterior table, displaced or non-displaced •• Anterior and posterior table, displaced or non-displaced 9 SRPS • Volume 11 • Issue R8 • 2015 •• Any of these fractures can include the nasofrontal duct It is generally agreed that an isolated non-displaced anterior table fracture can be treated nonoperatively. Displaced fractures of the anterior table generally are treated with surgery. In cases in which the nasofrontal duct is not thought to be involved, reduction of the fracture with preservation of the sinus is warranted. The fracture should be reduced with minimal manipulation of the mucosa as long as nasofrontal duct injury is unlikely. After reduction, fixation is performed with 1.0-mm microplates or 1.3-mm plates, depending on the amount of stability necessary. If the fracture is multifragmented, the bone can be discarded and bone grafting is indicated. Radiological evidence of air fluid level and direct visualization of the duct during surgery help determine duct patency. Injecting of the duct with saline or dye and applying dry gauze in the middle meatus of the nasal cavity can help with assessment. If the gauze stains, patency of the duct is suggested. If staining is not observed, the nasofrontal duct is probably occluded and obliteration of the sinus is indicated. No one test clearly indicates duct injury, but most surgeons agree that obliteration of the sinus is indicated if duct injury is suspected. Treatment of posterior table fractures is more controversial. Rohrich and Hollier46 stated that if the displacement of the posterior table is less than one table thickness, nonoperative management can be considered. Others think that any fracture of the posterior table, regardless of the amount of displacement, should be explored to rule out injury to the duct and the dura, which are difficult to assess radiographically.47 The potential severity of both acute and chronic complications is too grave to leave untreated, in their opinion. If CSF leak is noted, some surgeons consider this an immediate indication for surgery whereas others consider initial conservative treatment with elevation of the head and observation for 5 to 7 days to assess persistence of CSF leak. If the leak persists, cranialization and dural repair are recommended (Fig. 5).44 Dura can be repaired directly, or a periosteal or galeal flap or free fascia can be used. Rohrich and Hollier suggested an algorithm for the management of frontal sinus fractures (Fig. 6).46 Considering that the frontal sinus is stronger than the midface bones but weaker than the frontal bones, associated midface fractures are not uncommon and should be suspected. 10 Complications The main complications that occur in association with frontal sinus injuries are infectious and obstructive in nature. They can be divided into early and late complications. Early complications, occurring during the first 6 months after injury, include sinusitis, meningitis, extradural or intradural abscesses, intracranial abscesses, and osteomyelitis of the frontal bone. Sinusitis presents with frontal headaches, and radiographs or CT scans might show opacification or fluid levels, respectively. Initial treatment can be conservative with decongestants and antibiotics, and surgery is indicated in persistent cases. Meningitis is fortunately rare but does occur, especially when the posterior table is involved and a CSF leak is present. Ioannides et al.48 reported two cases of meningitis in 71 patients who underwent surgery for fractures of the frontal sinus. The meningitis was successfully treated with antibiotics. Dura Temporalis muscle plug Figure 5. Cranialization of a frontal sinus fracture with comminution of the posterior wall. The posterior table is excised, the nasofrontal duct is plugged with temporalis muscle, and the anterior wall is reduced and stabilized with rigid fixation, supplemented by bone grafting as necessary. (Reprinted with permission from Luce.44) SRPS • Volume 11 • Issue R8 • 2015 Anterior table fracture Combined anterior and posterior table fracture Displaced Displaced posterior wall No No operative intervention Yes No (<1 table width) Nasofrontal duct involved No Reduction and stabilization with sinus preservation Yes Yes (>1 table width) CSF leak No CSF leak Yes No Reduction and stabilization and sinus obliteration Yes 1. Reduction and stabilization of anterior wall 2. Cranialization Nasofrontal duct involved No operative Allow 4 to 7 days intervention for resolution. If persistent, consider cranialization No 1. Reduction and stabilization of anterior wall 2. Sinus preservation Yes 1. Reduction and stabilization of anterior wall 2. Sinus obliteration Figure 6. Algorithm for the management of frontal sinus fractures. (Modified from Rohrich and Hollier.46) Late complications mainly include mucoceles and mucopyoceles and usually occur several years after injury. The anatomic bases for these complications are obstruction of the nasofrontal duct, which occurs in one-third to one-half of frontal sinus fracture cases, and inadequate resection of sinus wall mucosa. The nasofrontal duct passes through the anterior ethmoidal air cells exiting adjacent to the ethmoidal infundibulum. Obstruction of the duct prevents adequate drainage of the normal mucosal secretions. This in turn disposes to development of obstructive epithelium cysts: mucoceles or, if infected, mucopyoceles. Mucoceles can also develop when islands of mucosa are trapped by scar tissue within the fracture lines and attempt to grow after injury, creating obstructed mucous membrane-lined cystic structures.49−51 11 SRPS • Volume 11 • Issue R8 • 2015 To avoid these complications, one must completely obliterate the entire frontal sinus mucosa by burring the bone and eliminating the duct mucosa rather than merely stripping the mucosa. Regrowth of the entire sinus mucosa has been demonstrated to occur from the remaining ductal mucosa or from the foramina of Breschet, which are invaginations of mucosa along the channels or veins extending into the bones.47,52,53 Donald54 suggested this concept of tenacity of the frontal sinus mucosa. Hardy and Montogomery55 reported a series of 250 patients. Most patients who suffered from chronic frontal sinusitis did not respond to antibiotics and needed obliteration of the sinus. Four percent required secondary revisions. Manson et al.56 reviewed the postoperative results of 42 frontal cranioplasties for which wire mesh methylmethacrylate or autogenous bone was used. Despite previous reports of high infection rates with acrylic cranioplasties, the authors reported no difference in complications based on the reconstructive material. Risk factors associated with infections were timing of the procedures and communication of the reconstruction with previously infected ethmoid sinuses and the nose. History of previous bone infections (62% in their series) and absence of the frontal sinus were considered risk factors for infection. Anatomy The frontal process of the maxillae is the main structural buttress of the NOE area (Fig. 7).1 It articulates superiorly with the nasal process of the frontal bone (also termed the internal angular process), medially with the nasal bones, laterally with the zygoma, and posteriorly with the laminae papyracea at the frontoethmoidal suture. The medial canthus-bearing area is also referred to as the central fragment (Fig. 8) and shows typical fracture patterns.64 The anterior and posterior ethmoidal foramina carrying the respective vessels are located at the upper portion of the lamina papyracea and mark the inferior border of the cranial fossa (Figs. 9 and 10).65 Any procedure performed above this area risks injury to the brain. Cranially, the nasal process of the frontal bone lies anterior to the frontonasal duct. Therefore, the nasofrontal duct usually is not involved. In cases of highly comminuted NOE fractures, patency of the nasofrontal duct can be lost and obliteration of the frontal sinus might be necessary.66 The nasal bones often are fractured, but nasal support mainly depends on the nasal pyramid proximally and the cartilaginous septum distally. Depending on the degree of comminution of these structures, the need for nasal bone grafting is determined. Nasoorbitoethmoid (NOE) Fractures Definition The simplest definition of an NOE fracture is a fracture that causes displacement of the section of the medial orbital rim, which carries the medial canthal ligament. The simplest NOE fracture can theoretically involve solely the medial orbital rim, although this is rare. Since the midfacial skeleton is the area of the NOE area, most NOE fractures involve the area of confluence of the nose, orbits, and ethmoids.57 The anatomic structures involved include the nose, medial and lower orbits, frontal sinus and anterior skull base, and pyriform rim. Therefore, NOE fractures have the potential to injure the skull base with associated dural tears and CSF leaks58,59 or injure the frontal sinus and nasofrontal duct. NOE fractures always involve the orbital floor and medial orbital wall.60−63 Successful reconstruction of these structures in a Threedimensional pattern is one of the most difficult challenges in facial trauma. 12 Figure 7. Frontal process of the maxilla is the main structural buttress of the naso-orbital-ethmoid area containing the insertion of the medial canthal ligament (inset). It is referred to as the central fragment. (Modified from Prein and Rahn.1) SRPS • Volume 11 • Issue R8 • 2015 A B Figure 8. A, Illustration of the central fragment of the nasoethmoid fracture. B, Butresses of the nasoethmoid area. (Reprinted with permission from Markowitz et al.64) Frontal bone Supraorbital foramen Ethmoid bone Lacrimal bone Zygomaticotemporal foramen Nasal bone Zygomatic bone Zygomaticofacial foramen Infraorbital foramen Maxillary bone Figure 9. Anatomic landmarks of the NOE region. The frontonasal suture can be followed posteriorly to the lacrimal fossa and ethmoid bone. The medial canthal tendon attaches on either side of the lacrimal fossa. During medial canthopexy, the tendon should be reattached just behind the apex of the lacrimal fossa. (Modified from Brady et al.65) 13 SRPS • Volume 11 • Issue R8 • 2015 Optic canal Frontal bone Posterior ethmoidal foramen Sphenoid bone, lesser wing Anterior ethmoidal foramen Ethmoid bone Sphenoid bone, greater wing Optic strut Superior orbital fissure Foramen rotundum Maxillary bone Inferior orbital fissure Figure 10. Anatomic landmarks of the NOE region. The ethmoidal vessels emerge through the anterior and posterior ethmoidal foramina along the fronto-ethmoidal suture. Dissection should be kept below the level of the vessels and away from the optic nerve (i.e., it should go no farther than the posterior foramen. (Modified from Brady et al.65) Fractures of the NOE complex often occur because of direct blow to the upper bridge of the nose, as often occurs with motor vehicle collisions when the face hits the dashboard or steering wheel. Because of the use of air bags in most cars, the incidence of these fractures has dramatically decreased. Markowitz et al.,67 reviewed the University of California Los Angeles experience with NOE fractures during a 4-year period in the mid-1980s. Of 342 patients treated for midface fractures, 105 had NOE fractures. Of the 105 NOE fractures, 4.8% were classified as high-energy injuries. This agrees with findings presented by Swearingen68 on tolerance of the human face to crash impact, that the force necessary to fracture the nasal bones is 30 G (Fig. 11).69 However, the force needed to fracture all surrounding structures is substantially less and the surrounding structures of the nasoethmoid complex will therefore “collapse and splinter like a pile of matchboxes struck by a hammer.”59 14 Classification Several classifications of NOE fractures exist. More important is that the clinician must understand what is occurring to the medial orbital rim segment, which bears the medial canthal attachment, because this will classify the fracture type and dictate the treatment. Perhaps the most commonly used classification based on fracture patterns was that described by Markowitz et al. (Fig. 12).64 It describes three main fracture patterns based on the fracture pattern concerning the medial canthusbearing bone. With type I NOE fractures, the canthusbearing segment is large and single. It can be complete or incomplete greenstick at the internal angular process and can be unilateral or bilateral. With type II fractures, the canthus-bearing segment is comminuted but the canthus-bearing bony segment is still large enough that it can be stabilized by plates. With type III fractures, severe comminution is present and the medial canthus is attached to a diminutive piece of bone that generally needs to be detached to successfully perform direct canthopexy. SRPS • Volume 11 • Issue R8 • 2015 Based on these patterns, treatment options can be chosen. With type I fractures, reduction of the medial canthus into position can be performed by fixation of the bone with a combination of microplates and miniplates. With type II fractures, treatment occasionally can be performed solely by plating but transnasal wiring usually is necessary. With type III fractures, the medial canthus must be detached from the bony segment and independently canthopexied with transnasal wiring. Figure 11. Resistance of various parts of the facial skeleton to fracture-producing forces. (Reprinted with permission from Luce et al.69) Diagnosis Physical Examination—Any central midface injury should raise suspicion for a NOE fracture. Severe nasal injuries can be misdiagnosed as NOE fractures, but, more commonly, NOE fractures are misdiagnosed as nasal fractures. The clinical appearance is typical. The nose is flattened with loss of dorsal nasal prominence, and the angle between the lip and nasal columella is obtuse. The medial canthal areas are swollen and distorted with palpebral and subconjunctival hematomas. Ecchymosis and subconjunctival hemorrhage are nearly always seen. Telecanthus is a common finding, although substantial swelling might mask it. To confirm medial canthal involvement, the surgeon should grasp the medial canthus with forceps and retract it laterally. If the canthus cannot be pulled taut, the medial canthus is likely involved. If diagnosis remains uncertain, a bimanual examination can be performed in the operating room. The finger is placed over the medial canthus and a clamp is placed intranasally and pushed against the finger. Mobility of the canthusbearing segment confirms the diagnosis. Intranasal examination reveals swollen, bulging mucosa and septal fractures. Septal perforation is not uncommon. Septal hematoma must be treated immediately by evacuation to prevent septal perforation. Nasal lining might be torn and devascularized, decreasing the survival of bony fragments. Clear fluid from the nose is strongly suggestive of CSF rhinorrhea70 by mechanism of extension of the fracture to the cribriform plate through the perpendicular plate of the ethmoid. CSF rhinorrhea nearly always presents as blood Figure 12. Classification of NOE fractures. Left, Type I. Center, Type II. Right, Type III. (Reprinted with permission from Markowitz et al.64) 15 SRPS • Volume 11 • Issue R8 • 2015 but within a few days usually clears to clear fluid. Several tests are available to confirm whether the fluid is CSF. One should look for the double-ring sign, also known as the halo sign. The test is performed by placing the fluid on a towel. The blood remains in the center and the CSF migrates laterally, thus creating a double ring. The fluid can also be tested for glucose levels, with levels above 30 mg/dL confirming a leak. For the most reliable proof, the fluid is tested for B-transferrin. Radiographic Examination—CT scanning is the gold standard imaging modality for examining NOE fractures.71 Four fractures must be revealed for the diagnosis of NOE fracture: 1)Frontal process of the maxillae 2)Nose 3)Medial and inferior orbital rims 4)Medial orbital wall and orbital floor Additional fractures might be noted. Fractures of the anterior cranial fossa often are difficult to detect. Air in the subdural or extradural space or, rarely, in the ventricle is evidence of communication between the nasal cavity or frontal sinus and the intracranial area. Frontal sinus fractures might also be seen in conjunction with NOE fractures. Le Fort level II or III fractures might also be present.72−74 Markowitz et al.64 reported that 36% of his series of NOE fractures were unilateral. Treatment All patients suffering from NOE fractures should be considered to have brain injury until proven otherwise. If the fracture involves the anterior cranial base or depressed or open frontal skull, neurosurgical intervention is needed. In the absence of frontal bone or sinus involvement, fractures of the anterior skull base usually are short, linear, non-displaced, and not in need of neurosurgical intervention. As a general rule, even if brain injury is suspected or has not been ruled out, surgery of the facial fractures should proceed if appropriate intraoperative intracranial pressure monitoring is available. Thorough exposure of the fracture is necessary for successful reduction and fixation. Three incisions 16 are needed: gingivobuccal, lower eyelid, and coronal incisions.57,60,64,67,75−79 Rarely, if a large open wound is found in the forehead, it can substitute for a coronal incision. Incisions should not be extended because of poor aesthetic results, nor should the “open sky” approach via a transverse incision across the root of the nose, as described by Converse and Hogan,80 be used. Excellent exposure means complete subperiosteal elevation of the globe from the floor of the orbit via the eyelid approach and complete dissection of the orbital roof and medial orbital wall via the coronal approach leaving the medial canthus intact. The key for successful reduction of the NOE fracture is transnasal reduction of the medial orbital rims by placing transnasal wiring posterior and superior to the canthal ligament insertion. The drill holes are placed superior and posterior to the lacrimal fossa. To ease the drilling, the canthus-bearing segments can temporarily be pulled anteriorly. No. 26 wires are inserted through the segment and transferred to the contralateral medial canthusbearing segment across the interorbital space. The wires are tightened only after the medial canthus-bearing bones are reduced into place (Fig. 13).64 When wire tightening is used to reduce the fractures, the wire nearly always cuts or microfractures the thin bone. Once the canthus-bearing segments are reduced and fixated, the surrounding bone segments should be reduced and fixated with microplates. On rare occasions, the medial canthal tendon is avulsed from the bone to create a type III fracture. In reality, this occurs more often iatrogenically, during dissection of the medial orbital wall, than from the original injury. The medial canthal ligament has three main limbs: anterior, posterior, and superior with an inferior free border. Anderson81 and Zide and McCarthy82 emphasized the importance of a vertical component of the medial canthal tendon. The posterior and superior limbs are the key elements of exerting the force that keep the eyelid tangent to the globe. Anderson,81 Zide and Jelks,83 and Zide and McCarthy82 proposed that the posterior and superior branches of the canthus are responsible for the vertical canthal position. Considering that the posterior limb is weak, the suture is passed through the anterior limb but fixation is directed toward the posterior limb attachment. The preferred technique presented by Markowitz et al.64 (Fig. 13) is identifying the medial canthal tendon from an external incision just medial to the medial commissure of the eyelid and passing a 2-0 braided non-absorbable suture through the tendon twice. After inserting two trans-nasal SRPS • Volume 11 • Issue R8 • 2015 Complications Complications of fractures in the orbital region associated with orbital or NOE fractures include diplopia, retrobulbar hematoma, implant or bone graft complications, visual loss, lid complications, and ptosis of the upper lid. Some of these are discussed in further detail in the section on orbital fractures. Complications that are uniquely associated with the NOE fractures are lacrimal system injury and telecanthus. Figure 13. A, Transnasal wire in front of the canthal ligament allows splaying of the posterior aspects of the fracture. B, Posterior transnasal wire prevents rotation of the medial orbital rim. (Reprinted with permission from Markowitz et al.64) Lacrimal System Injury—Most lacrimal system obstructions occur from malpositioning of the bone rather than direct damage to the lacrimal apparatus.64,84,85 Becelli et al.86 reported a 47% incidence of lacrimal obstruction after NOE fractures, one-third of which cleared spontaneously. Many of the patients in that series received late primary treatment. If obstruction persists, external dacryocystorhinostomy is 94% successful in eliminating the obstruction. If transection of the canalicular lacrimal system has occurred, repair should be performed over fine tubes with magnification. wires in addition to those that may be used for reduction of the medial segments, the suture is tied down after the wires have been singed down. It is important to emphasize the that anatomic landmarks through which the transnasal wires are passed are just posterior and superior to the lacrimal fossa, but the wire should never be superior to the frontonasal suture and frontoethmoid sutures and anterior and posterior ethmoidal foramens, all indicating the lower limit of the anterior cranial fossa. Any wire above that level could result in direct brain injury. Also, the wire should not be passed posterior to the posterior ethmoidal artery because of the risk of injuring the optic nerve. The cartilaginous nasal septum often is destroyed and does not provide sufficient nasal support. Primary bone grafting is necessary in such cases, and the graft usually is attached to the proximal nasal bones (Fig. 14).13 Cartilage graft might also be needed to provide columellar support. Figure 14. With this technique, a plate is attached by short screws to the underside of the proximal portion of the bone graft to stabilize it to the frontal bone. A dorsal nasal bone graft can be used to increase nasal height or produce a smooth nasal dorsal contour. The illustration shows a case in which a thin graft works well. Its marrow has been hollowed out to produce a shell of the bone graft, which provides only thin smooth covering over the reassembled fracture fragments. (Modified from Mathes.13) 17 SRPS • Volume 11 • Issue R8 • 2015 Telecanthus—Residual telecanthus characterized by increased intercanthal distance, flattening of the nasal root, and, frequently, dysfunction of the lacrimal system, is caused by late treatment or, more commonly, inadequate reduction of the NOE fracture. The medial canthus is rounded, with narrowing of the palpebral opening and epiphora. Normative values for intercanthal distance have been described as being 33 to 34 mm in Caucasian men and 32 to 33 mm in Caucasian women, but the best way to confirm abnormal distance is to compare the medial to lateral canthal distance on the injured side with that of the normal side.76 Secondary correction of telecanthus is much less successful than accurate primary correction. Orbital Fractures Definition Orbital fractures include simple fractures that involve the internal orbital bones—also known as blowout fractures— and fractures involving the orbital rims and internal orbit.87−89 They commonly are associated with other facial fractures, such as malar, Le Fort, or NOE fractures. Anatomy Appreciating the anatomy of the orbit is key to understanding the mechanism, patterns, and treatment of orbital fractures. The orbits are the bony cavities, which encompass the globes and surrounding structures, and are separated in the midline by the interorbital space, which contains the ethmoid and frontal sinus.90−92 The strong bone structure of the orbital rim protects the orbital content. The inferior orbital rim consists of zygoma laterally and maxilla medially. The medial orbital rim consists of the nasal bones, the nasal spine of the frontal bone, and the frontal process of the maxilla. The superior orbital rim consists of the supraorbital rims, and the lateral orbital rim consists of the zygomatic process of the frontal bone and frontal process of the zygoma. The orbital cavity is comprised of seven bones: the frontal, maxilla, zygoma, ethmoid, lacrimal, greater and lesser wings of the sphenoid, and the palatine bone. The orbital floor consists of the orbital surface of the maxilla, the maxillary process of the zygoma, and the orbital process of the palatine bone. The floor is separated from 18 the lateral wall by the inferior orbital fissure, and the infraorbital nerve in its canal originates in the anterior third of the fissure, progressing nearly straight anteriorly toward the infraorbital foramen. The orbital floor bulges upward immediately behind the globe, contributing to the forward globe support. The anterior portion of the floor is concave and the remaining posterior portion is convex. The inferior oblique muscle arises from the maxillary portion of the orbital floor immediately posterior to the rim and lateral to the lacrimal groove. The inferior rectus muscle lies immediately above the infraorbital canal. These muscles can be involved in fractures that involve the medial aspect of the orbital floor and medial orbital wall. Fractures involving the orbital floor lateral to the infraorbital groove or canal less commonly cause entrapment of these muscles. The medial wall is comprised anteriorly of the sturdier frontal process of the maxilla and posteriorly of the lacrimal bone, lamina papyracea of the ethmoid bone, and lesser wing of the sphenoid that incorporates the optic canal. The lamina papyracea is the thinnest bone in the body yet is slightly more resistant to fractures than is the thicker orbital floor because of the honeycomb bony structure of the ethmoid sinus with its bony septa that provides additional strength. During dissection one must remember that the optic canal is not at the orbital apex but is rather more anterior and medial. Dissection should not proceed posterior to the posterior ethmoidal artery. Anteriorly lies the lacrimal fossa in which the lacrimal sac lies and where the nasolacrimal duct originates and travels toward the inferior nasal meatus. The lateral orbital wall consists of the zygoma and sphenoid bone. The superior orbital fissure runs between the orbital roof and the lateral wall. The fissure separates the lesser and greater sphenoid wing and allows passage of the nerves innervating the ocular muscles (Cranial Nerves III, IV, and VI) and the ophthalmic division of the trigeminal nerve. Anteriorly and laterally, the fissure is related to the temporal fossa, and posteriorly, a small portion abuts the middle cranial fossa and the temporal lobe. Between the lateral wall and orbital floor is the inferior orbital fissure leading to the infratemporal fossa, which includes the maxillary portion of the trigeminal nerve and veins communicating to the temporal fossa. SRPS • Volume 11 • Issue R8 • 2015 The orbital roof contributes to a portion of the floor of the anterior cranial fossa and consists of the orbital plate of the frontal bone and a small posterior contribution from the lesser wing of the sphenoid. The roof is especially thin medially. The medial superior orbital rim is where the pulley (trochlea) of the superior oblique muscle and, slightly laterally, the supraorbital and supratrochlear nerves are located. Fractures in the medial superior orbital rim region can therefore cause diplopia and anesthesia of the forehead and scalp. The bony orbit can be conceptualized in anterior, middle, and posterior thirds. The anterior third is the thick bony orbital rim. The middle section is thin and often breaks before the rim absorbing fracture energy, and the posterior third is thick and is generally protected from fractures in most cases. Thus, the middle portion of the globe often fractures first and the rim second, protecting the posterior segments that include the most important neurovascular structures and also the globe itself from rupture. If the middle portion were thick, the globe would most likely rupture in every orbital trauma. The orbital dimensions are very important to remember (Fig. 15).91 The widest diameter of the orbit is 1 to 1.5 cm behind the rim and not at the rim itself. Posterior to that area, the orbit narrows dramatically. As previously noted, the optic foramen lies on the superomedial aspect of the medial wall in the orbital apex. In children, the orbital floor lies more inferiorly in relationship to the inferior orbital rim because the maxillary sinus is not well developed. Knowing the structure and measurements of the orbit assists in the safe dissection of the orbit when treating orbital fractures. Surrounding the globe is an intricate system of supportive ligaments (Fig. 16).93 This system provides support to the globe and prevents significant vertical height loss of the globe when orbital fractures occur. Manson et al.,94 Iliff et al.,95 and Koornneef96 described in detail this ligamentous support system. The system includes several structures: the medial and lateral canthal ligaments; an inferior sling comprised of Lockwood ligament,93 condensations of the inferior rectus muscle, and Tenon capsule;97 a fascial structure that subdivides the orbital cavity into an anterior (or precapsular) and posterior (or retrocapsular) segment; and a superior sling composed of Whitnall ligament, condensations of the levator and superior rectus fascia, and Tenon capsule. 35 45 36 40 17 Figure 15. Orbirtal dimensions (in millimeters) from the rim to the internal landmarks of the internal orbit. (Modified from Manson and Iliff.91) Diagnosis History—Orbital fractures are sometimes isolated but often are associated with other facial fractures. A history of the accident, visual disturbance, visual acuity, visual problems before the trauma, and previous ocular surgery should be documented. Patients seldom note previous unilateral visual disturbances because of compensation from the other side, but after surgery, the disturbances might be notable and blamed on the surgeon. Physical Examination—A thorough eye examination must be performed in any patient with orbital fractures. The incidence of ocular injury with facial fractures has been reported to be 7% to 40%.98−102 Fifteen percent to 20% of patients with major facial trauma suffer vision-threatening injuries. Soparkar and Patrinely103 suggest a systematic approach for eye examination in the setting of trauma. We recommend this article to every plastic surgery resident. It provides a simple guide for an ocular examination in the setting of trauma in addition to an ophthalmology specialist evaluation. Among other issues, this article emphasizes the importance of the red color saturation in assessing optic nerve function and the importance of visual field examination. Additionally, examination should detect edema, corneal abrasions, contusions, lacerations, and retrobulbar and vitreous hemorrhage and should exclude globe injury, extraocular muscle injury, levator muscle 19 SRPS • Volume 11 • Issue R8 • 2015 injury, levator tendon injury, and retinal detachment. A subconjunctival and periorbital hematoma confined to the orbital septum should be considered sine qua non with an orbital fracture until proven otherwise. Another good review of ocular examination was presented by Gossman et al.104 It provides a guideline for ocular examination by the non-ophthalmologist without specialized equipment within 5 minutes. In any case of orbital trauma, a detailed examination must be performed before reducing and performing fixation of the fracture (Fig. 17).105 Traumatic Optic Neuropathy Once globe rupture has been ruled out, the incidence of blindness associated with optic neuropathy is reported to be 2% to 2.4%.106−108 The mechanism is thought to be either direct blunt trauma to the optic nerve109 or nerve ischemia secondary to nerve compression secondary to edema, hemorrhage, or, rarely, fracture of the narrow optic canal.104 Operative treatment can cause further damage by the same mechanism.110−113 High-resolution CT scanning is important in cases of diminished visual acuity and can identify the cause of blindness, most commonly found to be swelling of the optic nerve, followed by fractures within the optic canal.114−117 The ideal management of optic neuropathy is somewhat controversial. Most physicians agree that prognosis is significantly worse if a patient presents with blindness compared with a patient who is progressively losing their sight. Wang et al.118 evaluated 61 consecutive patients presenting with visual loss after incurring facial trauma. Outcomes of three groups of patients based on treatment modality were retrospectively compared. Treatment options were high-dose steroids, surgical intervention, and observation. Twenty-seven percent of patients who presented with no light perception improved, compared with 100% of those who had light perception or better at presentation. Patients suffering from penetrating trauma also had a worse prognosis. Additionally, improvement was observed in 38% of patients with orbital fractures versus 83% of patients without orbital fractures. Based on these findings, the authors suggested an algorithm for management of optic neuropathy based on degree of visual loss (Fig. 18). They recommended use of megadose steroids for all patients with optic neuropathy regardless of mechanism or degree 20 of visual loss at presentation. Other authors suggested a steroid regimen consisting of a loading dose of 30 mg/kg of methylprednisolone and then 15 mg/kg 2 hours later and every 6 hours.119 Based on a review of 34 patients, Mine et al.120 suggested that surgical decompression of the optic canal results in improved vision in patients who can initially perceive hand movements or better versus no improvement in patients who present with only light perception or worse. Radiological Examination CT scans, including axial and coronal planes with bony and soft-tissue windows, are the most informative radiographic modality. Additional sagittal views, which are regularly obtained at many institutions, help reveal the posterior extent of the fracture with its relationship to the orbital apex and visualize the inclination of the orbital floor; 1.5-mm sections are recommended unless threedimensional reconstructions are required, in which case 1-mm sections are preferred. In general, three-dimensional views are not necessary. CT scans can suggest muscle entrapment, but physical examination is more informative. The scans can also suggest which patients might develop enophthalmos based on volumetric measurements.121 No clear radiographic indication for surgery has been delineated, but some authors have suggested surgery for defects larger than 1 cm2.72,122 −125 Treatment The goals of orbital fracture treatment are restoration of function and form. They can be summarized as follows: •• Release all soft-tissue structures of the orbit and restore ocular range of motion. •• Restore orbital content into the confines of the orbit and restore orbital volume and shape. •• Restore the orbital wall into its original shape, thus allowing the tissue to presumably scar in a position closest to the original anatomic position. Indications for surgery are not standardized and are somewhat controversial. SRPS • Volume 11 • Issue R8 • 2015 Medial canthal lig. Palpebral limit of orbital septum Orbital septum Lateral extension of levator tendon Lacrimal component of orbicularis m. Lateral canthal lig. Lacrimal sac Lateral attachment of Lockwood lig. Medial attachment of Lockwood lig. Medial check lig. Lateral check lig. overlying lateral suspensory lig. Fascial bulbi (Tenon capsule) Lateral rectus m. Medial rectus m. Inferior rectus m. Figure 16. Suspensory apparatus of the eye. lig., ligament; m., muscle. (Modified from Lockwood.93) I. Cornea conjunctiva sclera Lucency Lacerations Abrasions Foreign bodies III. Iris Size Shape Iridodonesis Reaction to light Direct Consensual (Marcus-Gunn) V. Vitreous Hemorrhage Foreign bodies II. Anterior chamber Depth Hyphema Foreign bodies IV. Lens Lucency Subluxation Dislocation VI. Retina Edema (Berlin) Hemorrhage Disc Edema Arterial pulse Figure 17. Checklist for evaluating the injured eye. (Modified from Barton and Berry.105) 21 SRPS • Volume 11 • Issue R8 • 2015 Figure 18. Algorithm for the management of traumatic optic neuropathy. NLP, no light perception; LP, light perception. (Reprinted with permission from Wang et al.118) Globe malposition, whether enophthalmos, exophthalmos, or vertical dystopia, and double vision with CT evidence of incarcerated ocular muscle or forced duction suggest entrapment. Manson and Iliff126 stated that hypoesthesia in the infraorbital nerve distribution associated with rim fractures that are medially displaced and compressing the nerve is an indication for surgery. Some authors127 contend that increasing numbness is an indication for surgery. It is important to differentiate muscle incarceration from other reasons that can cause diplopia, such as hematoma, muscle edema, and neurogenic origins that will not respond to surgery. Timing Emergent surgery for isolated orbital fractures is rarely necessary unless muscle entrapment is suspected. In cases in which substantial edema, globe injury, or retinal detachment is present, delaying intervention is recommended. Significant edema can render surgery difficult by attempting to replace the tissue to its original anatomic space. Symptoms often subside, rendering surgery unnecessary. When substantial orbital fractures occur, early intervention is recommended for better functional and aesthetic results. In a larger series of facial fractures reported by Hakelius and Pontén,128 22% of patients with midface fractures had diplopia. The patients were evaluated 22 in two groups. Sixteen percent of those who underwent surgery within 2 weeks of the trauma had diplopia, and this occurred only when fatigued. Twenty-four percent of the group who underwent delayed treatment suffered from late diplopia. In a series of 50 patients who had delayed presentation of 4 weeks between accident and surgery, 43 patients experienced restricted ocular motion. Emery et al.,122 in a series of 179 patients, reported diplopia in 60% of untreated patients who initially presented with double vision. Double vision in a functional field of gaze associated with evidence of muscle or fat entrapment on CT scan is an indication for surgery.126 Correction of enophthalmos is more difficult in the delayed setting because the muscles or orbital ligaments or fat might have scarred in an abnormal position. Surgical intervention can worsen the diplopia by positioning the globe in the field of action of a shortened muscle and can risk additional injury to the muscles, which are closely located to the orbital walls in the posterior aspect of the orbit. Techniques The three most common incisions are the transconjunctival, subciliary, and subtarsal incisions. The transconjunctival incision is performed through the conjunctiva a few millimeters above the inferior fornix. Its most medial aspect should not go beyond the inferior punctum, which could risk injury to the canaliculi. Laterally, it can be extended as a lateral canthotomy through the inferior limb of the lateral canthus if exposure of the lateral orbital wall is needed. Once the incision is made, two approaches to the orbital floor are available: pre- and post-septal. A pre-septal approach necessitates incision through the lower lid retractors, dissection along the preseptal plane toward the arcus marginalis, and continued dissection in the subperiosteal plane. A post-septal approach can be used with direct approach to the orbital fat, avoiding contact with the lower eyelid. If further exposure of the lateral orbital wall is needed, a lateral canthotomy can be performed by incising the lower limb of the lateral canthus. Accurate reattachment of the inferior limb to its original location at Whitnall tubercle is necessary to avoid malpositioning the lower eyelid. If medial extension is needed to address the medial orbital wall, a transcaruncular approach can be used.129 The subciliary approach is performed 1 to 2 mm inferior to the SRPS • Volume 11 • Issue R8 • 2015 lower eyelid lashes. Care should be taken not to injure the lashes. With this approach, dissection usually is performed between the orbicularis oculi muscle and orbital septum pre-septally. Manson et al.130 modified the subciliary approach with a lateral extension below the lateral canthus to enable access to the lateral orbital wall and zygomaticofrontal suture. The subtarsal approach allows access to the orbital floor via an incision just inferior to the tarsus in a subtarsal crease. The dissection proceeds in the pre-septal plane down to the orbital floor. It is useful, especially in the older population in which the subtarsal crease is deep and the scar can be well hidden. Restoration of Orbital Wall Continuity The primary goal of orbital repair is restoration of the volume and shape of the orbit. The secondary goal is separation of the orbit from the maxillary sinus. If orbital exploration is indicated, repair of the orbital floor is required in almost all cases other than cases in which entrapment occurred in a very small trapdoor deformity and the orbital contents remain in the orbit after their reduction. Alloplastic materials are currently most commonly used, and few plastic surgeons continue to use bone grafts. Several studies compared the approaches in terms of postoperative risk for ectropion and scleral show. Appling et al.131 reviewed the cases of 163 patients who underwent either a subciliary or a transconjunctival incision approach for orbital floor repair. In the subciliary group, 28% developed permanent scleral show and 12% developed transient ectropion. With the transconjunctival approach, 3% developed transient ectropion and 0% had permanent ectropion.132 Bone Grafts—The most common bone grafts used are calvarial grafts.133 Less commonly used bone grafts are split rib grafts. Antonyshyn et al.134 reported superior results with bone grafts. The potential advantage is revascularization of the bone, but perhaps more important is the decreased adhesions of the orbital content to the bone, as opposed to titanium or MEDPOR, if reexploration is required. Complete absorption of the bone was also reported. Dingman and Grabb135 reported use of irradiated or banked bone, but it is difficult to justify because of readily available donor bone. Dissection—Regardless of the incision chosen, it is key to perform the orbital dissection in the subperiosteal plain. Any other plain increases the risk for injury of the ocular muscles and other intraorbital structures. When incising the periosteum at the beginning of the exposure, it is advisable to tag the periosteal edges with sutures because they often are difficult to identify at the end of the case. Not all surgeons close the conjunctiva, but periosteal closure is paramount to avoid midface dropping and possible traction on the eyelid. During the subperiosteal dissection, it is important to identify the ledges of the fracture, especially the posterior ledge, which can be found even 40 mm posterior to the rim. The orbital content descending to the maxillary sinus should be gently retracted back to its intraorbital position rather than aggressively pulled, which could potentially cause damage. As noted previously, the surgeon should be familiar with the orbital dimensions and cognizant of the extent of the dissection, particularly with medial wall dissection. Once the dissection is completed and continuity of the orbital wall restored, a forced duction test should be conducted to verify full range of motion of the globe. Alloplastic Reconstruction—Several materials are available for orbital reconstruction including silastic,136 titanium, polymethylmethacrylate, Teflon,137,138 and high-density porous polyethylene (Porex Corporation, Fairburn, GA). MEDPOR (Stryker, Kalamazoo, MI) or titanium covered with MEDPOR is commonly used, and these materials have very low reported associated infection rates with the advantage of not creating a donor site defect. In their series, Choi et al.139 reported a series of 25 patients who underwent reconstruction with MEDPOR. During a follow-up period of 31 months, no infections or loss of structural support occurred. It is important to use thick enough implants (1.5 mm rather than 0.8 mm) to keep the reconstruction from bending toward the maxillae with subsequent enlargement of the orbit. It is also important to place any material far enough posteriorly on a stable ledge of bone and to fixate it with a screw to prevent anterior displacement and to avoid risk of extrusion through the eyelid. Use of the smooth portion of the implant toward the orbit is recommended to theoretically decrease the chance of adhesion of the ocular muscles to the surface. 23 SRPS • Volume 11 • Issue R8 • 2015 Hollier et al.140 reported use of absorbable plates, which are potentially most useful in the pediatric population. With a mean follow-up of 6 months, the authors reported enophthalmos in two of 12 patients and stated that it occurred secondary to initial placement of the implant rather than resorption. Bauman et al.141 reported different results. In their study, five of six patients developed enophthalmos after the use of resorbable implants for defects of 2.5 to 4.0 cm2. Complications Ectropion or retraction of the lower lid can occur from trauma, especially if the lower lid was directly involved in the initial trauma, or secondary to dissection. The pathological condition can occur secondary to scarring of the anterior, mid, or posterior lamellae of the eyelid. It more commonly occurs with subciliary incision,131 although it has been reported to occur with all incisions. Although not prospectively shown, it is the authors’ opinion that a transconjunctival post-septal approach might be the safest approach considering that dissection does not involve the lid structures. Aside from a careful and accurate anatomic dissection, an additional measure that can be taken is application of a frost stitch, a stitch that is inserted in the lower eyelid lateral to the lateral limbus and taped to the forehead or stitched behind the hair-bearing scalp. This provides additional mechanical support during the first 2 to 3 days after surgery and still permits examination of vision after surgery. If ectropion does develop, frequent massaging of the scar with supportive taping of the lid in a superior vector usually leads to resolution of the problem. If the ectropion persists beyond 6 months, it should be addressed surgically based on the lamellae involved. In the meantime, the cornea needs to be lubricated and protected to avoid permanent corneal damage. Enophthalmos—Acute enophthalmos is a consequence of increased orbital volume, but persistent enophthalmos results from inadequate restoration of orbital volume with subsequent scarring of the extraocular muscles causing contraction of the globe in the anterior-posterior vector. Early repair of all fractures involving the orbit usually result in less chance of enophthalmos compared with late 24 repairs, as was shown in a study by Dulley and Fells,142 who reported a 72% incidence of enophthalmos in patients who underwent repair more than 6 months after the initial trauma versus 20% in those who underwent repair within 14 days. In the late repair group, 40% of the patients required subsequent surgery of the muscle or orbit in an attempt to correct the problem. Per Manson et al.,143 insertion of implants into the orbit usually is not sufficient to correct the problem in the anterior to posterior direction, and complete orbital dissection to free the content from the orbit followed by orbital augmentation with calvarial bone grafts is necessary. Diplopia—Persistent diplopia after surgery can be caused by several different mechanisms: inadequate release of entrapped orbital content, scarring of orbital content to the orbital wall or repair, scarring and shortening of one or more of the ocular muscles, increased intraocular pressures, or neurogenic injury. A forced duction test must be used at the end of each surgery to verify that entrapment is not present. This test can be performed in an awake patient with appropriate administration of local anesthetic to rule out mechanical restriction. If motion is not limited by entrapment or scarring, diplopia is unlikely to have been caused by entrapment. In such cases, neurogenic diplopia might be the cause, which can take 6 months or longer to resolve.144 Biesman et al.145 reviewed the cases of 54 patients and found that 86% had preoperative diplopia defined as double vision interfering with daily activities and 37% percent had persistent diplopia over 6 months postoperatively. Such patients need to be followed by an ophthalmologist specializing in muscle surgery. If symptoms persist beyond 6 months, ocular muscle surgery should be considered. Infection Associated with Orbital Implants— Infection associated with orbital implants is rare and more commonly occurs with implants that form a pseudocapsule, such as silicone or Teflon, which prevents vascular ingrowth. Infection might also occur with a procedure that causes transient bacteremia.146−149 Highdensity porous polyethylene that allows some vascular ingrowth has been associated with very low infection rates. In cases of infection, implants should be removed. SRPS • Volume 11 • Issue R8 • 2015 Extrusion of Implants—Extrusion of implants is also a rare occurrence. Brown and Banks150 presented three patients who experienced extrusion of implants 10 to 17 years after initial surgery. When placing implants, they should be fixed to the orbital rim to prevent anterior displacement. Blindness—Blindness can occur after surgery for several reasons. Inadvertent injury to the optic nerve and resulting blindness can occur because of overzealous dissection, particularly along the medial orbital wall. Impingement of the optic nerve by an implant placed too posteriorly at the time of reconstruction can also occur. Postoperative retrobulbar hematoma is another potential cause. One of the first early signs of optic nerve injury is loss of ability to identify the color red during examination. Early diagnosis and emergent surgery are indicated, and, in most cases, emergent CT scanning of the orbit is recommended before performing surgery. Superior Orbital Fissure Syndrome (SOFS)—Rowe and Killey151 credit Hirschfeld with the first description of SOFS. SOFS is caused by extension of the fracture line into the superior orbital fissure, causing injury to cranial nerves III, IV, and VI and the ophthalmic division of cranial nerve V. This produces ophthalmoplegia, upper lid ptosis, proptosis, a fixed and dilated pupil, and sensory disturbance over the ophthalmic distribution of the trigeminal nerve, including the loss of the corneal reflex. On examination, the pupil is unresponsive to both direct and indirect light stimulation; however, the consensual pupillary response is intact, indicating that the optic nerve (the afferent arc) is uncompromised.152−155 Most patients with SOFS should be treated conservatively unless there is radiographic evidence of nerve compression. Orbital Apex Syndrome (OAS)—OAS is similar to SOFS except for the additional finding of blindness caused by direct extension of the fracture into the optic canal or severe optic neuropathy.156 Kjœr157 first described OAS in 1945. Treatment is similar to that described in the section of optic neuropathy. Trapdoor Fractures Trapdoor fractures generally are orbital floor fractures in which the fracture spontaneously reduces while entrapping orbital content as ligaments or muscle causing mechanical ocular motion limitation. These fractures usually are greenstick fractures that occur in the pediatric population, and some patients exhibit oculocardiac reflex (bradycardia, nausea, and syncope) caused by incarcerated orbital content.158 Blow-In Fractures Orbital blow-in fractures are uncommon. Decreases in orbital volume and increases in intraorbital pressure occur with these fractures.159 Orbital blow-in fractures sometimes include the rim; these are defined as “impure” blow-in fractures. Some do not involve the rim and are thus defined as “pure” blown-in fractures.160−166 Associated clinical findings include universal proptosis, diplopia (32%), upward vertical dystopia (i.e., upward displacement of the globe) (28%), globe rupture (12%), SOFS (10%), and optic nerve injury.164,167 Early intervention is key for successful treatment to prevent intraorbital damage secondary to increase in orbital pressures typical of these injuries. The treatment goal is relief of intraorbital pressure and restoration of orbital structure. Medial Orbital Wall Fractures Medial orbital wall fractures can involve the floor, be part of a NOE fracture, or be isolated. Medial orbital wall fractures might be tempered by the honeycomb architecture of the ethmoid sinus and occur slightly less frequently than do the thicker orbital floor fractures, but displacement of the medial wall will cause significant enlargement of the orbital volume. Entrapment of the medial rectus muscle is rare, occurring in fewer than 1% of cases,168 and the medial rectus muscle often is found to be contused. The medial wall can be approached from the floor via a transconjunctival incision with a transcaruncular extension,129 a subciliary or subtarsal approach, an upper blepharoplasty approach, or a coronal approach. The best view is achieved via a coronal incision. Whatever the approach chosen, if the medial wall fracture is extensive and involves the floor, the initial repair 25 SRPS • Volume 11 • Issue R8 • 2015 should be of the floor, thus providing a medial strut for stabilization of the additional bone graft or alloplastic material used for reconstruction. Often, the posterior extension of the fracture is to the posterior ethmoidal artery and dissection beyond this point risks injury to the optic nerve located approximately 5 mm posteriorly. Once exposure is obtained, the grafts or alloplast can be stacked on the inferior reconstruction until intraorbital volume is restored (Fig. 19).13 fracture rather than the orbital aspect to prevent decreasing the orbital volume and to avoid exophthalmos after repair (Fig. 20).13 Zygomatic Arch and ZMC Fractures Definition Zygomatic fractures include fractures of the ZMC, also known as malar fractures or isolated zygomatic arch fractures. Lateral Wall Fractures Isolated lateral orbital fractures are rare. The majority of lateral wall fractures are part of a more extensive fracture involving the floor and lateral orbital rim, such as occurs with zygomaticmaxillary complex (ZMC) fractures, which are discussed in detail in the following sections. Orbital Roof Fractures Orbital roof fractures are rare and usually occur as part of more extensive fractures, such as frontal sinus fractures and NOE fractures.165,169,170 The exception is isolated orbital roof fractures that occur in children younger than 7 years. Children of this age do not have a developed frontal sinus, and forces are thereby transmitted via the rim to the orbital roof. The classic presentation of these patients is exophthalmos, proptosis, upper eyelid ptosis, and diplopia.163,171 The medial orbital roof is weaker than the lateral roof and is therefore more involved in fractures.172,173 Posterior displacement can cause pressure on the superior orbital fissure, causing SOFS.154,174,175 If the fracture involves the optic canal, it can cause blindness, as occurs with OAS. If the superior rim of the orbit is involved, the trochlea of the superior oblique muscle can be displaced, causing diplopia in its field of action, which usually resolves spontaneously.176 The orbital rim and roof can be displaced superiorly or inferiorly and often are associated with brain injury or dural tears. Left untreated, cerebral content will herniate down into the orbit and cause the classic pulsatile exophthalmos in adults and inferior displacement of the orbit in the growing child. Treatment usually involves the neurosurgical team and repair of the brain, and dural injury should be performed before orbital repair. Once exposure is obtained, a bone graft should be secured on the cerebral aspect of the 26 Figure 19. Illustration shows bone grafting of a medial orbital defect. (Modified from Mathes.13) Figure 20. Illustration shows intracranial bone graft reconstruction of the orbital roof. (Modified from Mathes.13) SRPS • Volume 11 • Issue R8 • 2015 All ZMC fractures involve the orbital floor, lateral orbital wall, and zygomatic arch. Anatomy The zygomatic bone creates the lateral buttress of the midface. It forms the malar eminence, provides prominence to the cheek, and forms the lateral and inferolateral walls of the orbit. It has a quadrilateral shape and articulates to four adjacent bones: the maxilla, frontal, temporal, and sphenoid bones (Fig. 21).136 Therefore, fractures of this malar complex should be termed tetrapod fractures rather than the more commonly used misnomer, tripod fracture. The zygoma is the origin of several facial muscles, including the masseter, temporalis, zygomaticus major and minor, and zygomatic head of the quadratus labii superioris muscles. Malar fractures usually cause the zygoma to displace downward, medially, and posteriorly because of the forces of trauma but more so secondary to the pull of the masseter muscle. Nerves that pass through the zygoma include the zygomatic temporal and zygomatic facial nerves. The inferior orbital nerve passes on the medial aspect of the bone; therefore, fractures can cause numbness in related areas. With isolated zygomatic arch fractures, the arch might be significantly impacted medially and cause severe pain and possible mechanical impingement while attempting to open the mouth or during mastication. In cases of high-energy trauma with severe comminution of the arch, bony fragments might be pushed into the glenoid fossa, preventing mouth closure and creating an open bite. Because the lateral canthus is attached to the lateral orbital rim at Whitnall tubercle, inferior to the frontozygomatic suture compound, malar fractures often create an antimongoloid slant of the palpebral fissure. These fractures all include the orbital wall and can thus create significant vertical dystopia (Fig. 22).13 Diagnosis History—Understanding of the mechanism of the trauma provides information about the energy and direction of the force involved. In cases of penetrating trauma, the surgeon should seek potential foreign material embedded in the soft tissue. History can help diagnose a malar fracture or isolated zygoma fracture, but a good examination usually provides even more accurate assessment. Physical Examination—Typical findings in patients with zygomatic complex fractures, excluding fractures of the arch, are periorbital ecchymosis, edema, and subconjunctival hemorrhage. Because of the confinement of the bleeding by the orbital septum, a spectacle Figure 21. Zygoma and articulating bones. A, The zygoma articulates with the frontal, sphenoid, and temporal bones and the maxilla. Shaded areas show the portions of the zygoma and maxilla occupied by the maxillary sinus. B, Lateral view of the zygoma. (Modified from Kazanjian and Converse.136) A B Figure 22. A, Normal position of the lateral canthus in a fracture without displacement. The palpebral fissure slants slightly upward from the medial to the lateral canthus by several millimeters. B, Downward displacement of the globe and lateral canthus results from a frontozygomatic separation wth inferior displacement of the zygoma. The globe and periorbita are permitted to sink into an enlarged orbital cavity, and the lateral canthus with the attachment of the eyelids and orbicularis are dragged inferiorly as a result of the displacement. (Modified from Mathes.13) 27 SRPS • Volume 11 • Issue R8 • 2015 hematoma usually is created. Periorbital hematoma and subconjunctival hematoma are the most accurate physical signs of orbital fracture, which might include the zygoma. Ipsilateral numbness of the cheek, lip, nose, and teeth are typical because of some degree of injury to the infraorbital nerve. The lateral canthal ligament might be displaced inferiorly and the lower lid might be pulled inferiorly.177 Intraoral swelling can be detected by physical examination. Malocclusion or difficulty in moving the mandible can be caused by medial displacement of the arch or posterior displacement of the malar eminence. Enophthalmos and vertical dystopia might also be present with malar fractures.174,178,179 Some malar fractures are displaced medially, decreasing the volume of the orbit and causing exophthalmos. These blow-in fractures have been described by Antonyshyn et al.164 and by Stanley and colleagues.180,181 Radiology—CT scans are the radiographic images of choice for evaluating zygomatic fractures. Plain film radiographs are redundant if CT scans are obtained. Traditionally, the Waters view is the single best film to fully assess a malar fracture,182−185 but, as noted, CT scans yield the most information, especially if axial and coronal views are included, including soft-tissue and bony windows.186 Coronal views are especially helpful for evaluation of the orbital floor and the amount of orbital content descending into the maxillary sinus. Threedimensional CT reconstructions can be helpful when comparing the normal with the abnormal rim and malar eminences but is less accurate in evaluating thin bony fractures of the orbital walls.187,188 Intraoperative CT scans are gaining in popularity and have potential value in the management of zygomatic and ZMC fractures.189 However, the main goal of the use of CT scans is to enable accurate assessment of reduction. Postoperative CT scans are essential in evaluating reduction. Classification The main goal of classification systems151,190−196 was to define which fractures could be treated by closed reduction versus open reduction. Manson et al.195 and Afzelius and Rosén197 created a classification system based on the energy of the trauma. Higher energy traumas required more frequent operative intervention and wider exposure. 28 Treatment and Techniques Malar fracture treatment developed with facial trauma treatment. Cranial fixation devices, percutaneous fixations (such as Kirschner wires and direct fixation with interosseous wires), and immediate bone grafting when needed improved the results of treatment of facial fractures between 1960 and 1980.198,199 With the advent of rigid fixation devices (plates and screws) in the mid-1980s, results further improved and the need for bone grafting further decreased. The most important elements of malar fractures that determine the therapeutic approach are the amount of displacement and the degree of comminution of the fracture. Non-displaced fractures can be treated conservatively without operative intervention, but patients should be followed closely, two to three times during a six-week period. The forces exerted on the zygoma by the masseter muscle can displace the malar segment. If such displacement occurs, early surgical intervention is indicated. To decrease the chances of displacement during the period of observation until stable healing is achieved, the patient should be restricted to a soft diet, be instructed to avoid physical activities that would risk trauma to the area, and refrain from sleeping with pressure on the side of the injury. If any displacement is noted, most authors prefer surgical intervention. Some authors200 advocate closed reduction to treat minimally displaced fractures, but it is generally known that many surgeons advocate different degrees of exposure and internal fixation based on the degrees of displacement and comminution. Isolated fractures of the zygoma should be differentiated from fractures of the malar complex. Trismus caused by impingement of the temporal muscle by the zygomatic arch and contour deformity are the two main indications for surgery for isolated zygomatic arch fractures. The operative approach can be through the mouth. More commonly, a Gillies approach is used (Fig. 23).201 The technique involves a small incision in the temporal region, behind the hairline if possible, dissecting deep to the temporalis fascia and identifying the muscle. The elevator is inserted along the muscle inferiorly until it is deep to the arch. It is then leveraged on the calvaria to elevate the fractured segment. An audible click often is heard, and assessment is conducted by inspection and palpation intraoperatively. This procedure usually is successful because the periosteum SRPS • Volume 11 • Issue R8 • 2015 of the arch usually is intact because of the greenstick character of the fracture, allowing anatomic reduction with relative ease. Most isolated arch fractures remain stable after reduction,114,201,202 but some authors prefer to externally partially stabilize the fracture until healing is achieved.203,204 Stabilization can be accomplished by inserting two sutures deep to the arch and securing a rigid piece of fixation, such as an Aquaplast splint, over the fracture area. To avoid skin necrosis under the splint, the splint should not be excessively tightened. More complex zygoma fractures should be evaluated on an individual basis in terms of degree of exposure and fixation necessary to obtain good results. Most malar complex fractures can be treated via three incisions (Fig. 24).114 To expose the lateral zygomaticmaxillary buttress, an upper gingivobuccal incision is made, allowing exposure of the maxillae, zygoma, and inferior orbital rim. During this dissection, the infraorbital nerve is identified and protected. To expose the inferior orbital rim and, if needed, the orbital floor and lateral orbital wall, an eyelid incision (transconjunctival, subciliary, or subtarsal) can be used based on the experience of the surgeon. Exposure of the frontozygomatic suture is obtained via a lateral upper blepharoplasty incision or direct incision over the frontal zygomatic suture. A brow incision should be avoided because the alopecia that can occur secondary to scar is difficult to successfully treat. Manson et al.38 noted a preference to initially expose all the fractures and perform initial fixation of the frontal-zygomatic suture with 1.0- to 1.3-mm plates. The orbital rim is plated next, usually with a 1.0 plate applied to the superior aspect of the inferior orbital rim rather than externally to decrease chances of palpability. This is followed by the zygomaticmaxillary buttress reduction and fixation with the use of 1.5- to 2.0-mm plates, usually L plates. The tooth roots should be avoided when drilling the lateral buttress plates. In reality, screws that penetrate teeth have not had the frequency of adverse sequelae initially predicted.205 Only after reduction is verified are the plates secured. The anatomic area, which is most informative to the surgeon about the accuracy of reduction, is the congruity of the lateral orbital wall that can be ascertained either from within the orbit or externally via the temporal fossa. In cases of severe ZMC comminution or severe comminution of the arch, a coronal exposure might be needed. This is also indicated when reduction of a severely impacted malar fracture is not possible via more limited approaches. In these scenarios, it is difficult to orient and reduce the fractures via limited approaches and the reduction and fixation of the zygomatic arch provides pertinent information. Every surgeon who treats facial fractures should be knowledgeable in performing a coronal incision and exposing the zygomatic arch, while understanding the temporal anatomy and avoiding injury to the frontal branch of the facial nerve. Once the arch is exposed, a nearly straight plate should be used for fixation. Delayed Treatment of Zygoma Fractures As with any facial fractures, early reduction facilitates obtaining optimal results. Consolidation of the bones begins in the malreduced position as early as 1 week after injury and is organized in 3 weeks. Any delay in fracture repair of more than 2 weeks after the injury might require osteotome-assisted reduction because of fibrous or bony ankylosis. After mobilization is performed, all bony edges should be inspected and fibrous ankylosis or bony proliferation removed. Otherwise, malalignment will occur.206 In fractures that are treated late, a formal osteotomy should be performed rather than mobilization Skin Temporal parietal fascia Temporalis fascia Temporalis Zygomatic arch Mandible Figure 23. Temporal incision for reduction of isolated zygomatic arch fractures. A and B, Incision is continued through temporoparietal and temporalis fascia. C, Dingman elevator is placed deep to the temporalis fascia behind depressed zygomatic arch. (Modified from Feinstein and Krizek.201) 29 SRPS • Volume 11 • Issue R8 • 2015 Upper lid incision Subtarsal incision Gingivobuccal incision Figure 24. Common incisions for exposure of the zygoma. Upper and lower eyelid incisions are shown. (Modified from Rohrich et al.114) with blunt force. The latter could create additional fracture lines, which could extend into the orbital canal and cause blindness. In cases of delayed fracture repair, the masseter muscle might shorten and mobilization of the malar complex might be achieved only by cutting through its insertion into the inferior aspect of the malar eminence. Complications Early Complications— 1)Bleeding is a rare occurrence and usually is self-limiting. In cases of persistent bleeding that do not respond to direct cauterization, angiographic embolization might be required. 2)Sequestration of devitalized bone fragments can cause infections of the sinus (acute sinusitis). Inappropriate drainage of the 30 sinus increases the chance for sinus infection and can lead to the need for endoscopic sinus surgery to clear the sinus ostia. Failure to recognize inadequate sinus drainage can result in a persistent oral antral fistula in the sublabial region.207 3)Extraocular muscle injury can result from contusion or, less frequently, interference by bony segments or entrapment of muscle or fat. 4)Blindness has been reported to occur after malar fraction reduction.208,209 Late Complications— 1)Malunion most commonly occurs because of inadequate reduction caused by errors in judgement during surgery. This also occurs in untreated fractures that heal in malposition. Treatment consists of SRPS • Volume 11 • Issue R8 • 2015 removal of any applied plates and screws, osteotomies, and proper reduction and fixation.210 A malaligned fracture often results in bone loss and necessitates adding bone grafts to regain buttress height or malar projection. often occurs when closed reduction is attempted and can be caused by excessive reduction forces. If the arch abuts the coronoid process, fibroosseous ankylosis can occur, limiting the mandibular motion. If limited motions persists after reduction of the arch or if reduction is not possible, coronoidectomy via an oral approach is considered. If motion is regained after this procedure, vigorous postoperative exercise for up to 6 months is essential to preserve motion. 2)In general, ectropion and scleral show are mild and usually resolve spontaneously. An estimated 10% of patients undergoing subciliary approaches to the orbital floor develop temporary ectropion. 3)Diplopia and orbital dystopia can be caused by gross downward movement of the zygoma. An excess of 5 mm of inferior orbital dystopia is required to produce diplopia. Osteotomies, mobilization, reduction, and fixation are necessary for correction. If malar projection is deficient, bone grafting might be necessary.210,211 If enophthalmos is present because of loss of orbital volume, volume augmentation can be achieved by either bone grafting or artificial material, such as MEDPOR. 4)Enophthalmos or exophthalmos is caused by decreased or increased orbital volume, respectively, after trauma. Enophthalmos usually results in orbital floor involvement, and treatment is described in the orbital fracture segment. Exophthalmos results from a compressed malar fracture, and treatment consists of malar reduction with or without treating the orbital floor based on floor involvement. 5)Chronic infection usually results from preexisting sinus infections and can be caused by inadequate drainage of the sinus. Clearing the sinus with endoscopic surgery is recommended if osteotomies are planned for correction of malalignment. 6)Mandibular motion limitation and trismus can occur. Malposition of the zygomatic arch or body or bony fragments can interfere with motion of the coronoid process and require osteotomy.90,91 This 7)Persistent anesthesia or hypesthesia can occur, with hypesthesia resolving spontaneously in most cases.212,213 If it persists for longer than 6 months, it is most likely because of transection or entrapment of the nerve. If entrapment by scarring or compression of medially displaced zygoma is suspected, the surgeon can attempt to decompress the nerve, which includes the foramina, and along the course of the nerve in the orbital floor. Nasal Fractures Definition Nasal fractures include fractures of bony or cartilaginous portions of the nose, including the nasal septum. Anatomy The upper nasal skin that lies on the bony portion of the nose is mobile compared with the thicker, more sebaceous skin of the lower third of the nose that is more adherent to the cartilaginous portion of the nose. The rich blood supply of the nose allows extensive and safe submuscular dissection and results in early rapid healing of the soft tissue and bones of the nose. The supporting framework of the nose is comprised of a complex, semirigid, cartilaginous portion that is attached to a solid and inflexible bony structure of the nose. The cartilaginous portion includes the upper and lower lateral alar cartilages, the septal cartilages, and small sesamoid cartilages. The bony structure consists of the nasal spine 31 SRPS • Volume 11 • Issue R8 • 2015 of the frontal bone, the paired nasal bones and the bony septum, which includes the vomer and the perpendicular plate of the ethmoid. Proximally, the nasal bones are thick and narrow; distally, they are thinner and wider. Because of this configuration, proximal bony nasal fractures occur infrequently compared with distal bony nasal fractures. Classification Stranc and Robertson214 classified nasal fractures into lateral impact and frontal impact. Frequently both components are seen in one nasal fracture. Lateral and frontal nasal fractures can be divided into three planes. Plane I involves mostly unilateral displacement of the distal nasal bones into the nasal cavity. Plane II involves bilateral nasal bone fractures, the frontal process of the maxillae, and the septum. Plane III involves the fracture pattern seen in plane II and the frontal bone with extension into the medial orbital rim, creating a hemi NOE fracture (Fig. 25).13 Treatment In general, most nasal fractures can be reduced by closed techniques. Frontal impact fractures in planes II and III with loss of nasal height or length, should be treated with open reduction and primary bone or cartilage grafting to restore support and fill the soft-tissue envelope before irreversible concentric scarring occurs.215,216 Verwoerd217 described the indications for open and closed reductions in 1992. Summarized below are the modifications recommended by Metzinger et al.218 Indications for closed reduction are as follows: 1)Unilateral depressed nasal pyramid fractures with stable dorsum 2)Bilateral fractures without significant loss of septal height 3)Disruption of upper lateral cartilage from septum Indications for open reduction are as follows: Diagnosis Clinical Examination—Clinical examination must include external and internal nasal examinations. Mobility, crepitus, and tenderness are noted with nasal palpation. A hematoma over the nose extending into the periorbital area is present but does not extend beyond the insertion of the orbital septum, differentiating it from hematomas that occur in association with orbital fractures that do extend beyond the insertion of the orbital septum and are described as spectacle hematomas. Intranasal examination must be performed to rule out a septal hematoma. If present, a septal hematoma must be evacuated by a linear or L-shaped incision and closed with quilting sutures to avoid reaccumulation of blood. An untreated septal hematoma can result in septal infection and possible septal necrosis. For a properly performed intranasal examination, oxymetazoline should be applied to the nasal mucosa. Radiology—Plain film radiographs can help delineate nasal fractures, but the mainstay of radiographic diagnosis is the CT scan. CT scans reveal the most detail, delineate fracture pattern, which can be obscured by soft-tissue swelling, and, more importantly, confirm the absence of injury to adjacent bones, such as the maxilla and orbits. 32 1)Bilateral fractures with or without lateral dislocation of nasal dorsum but with significant septal injury and potential for loss of septal height 2)Bilateral fractures with buttress dislocation with or without major septal injury 3)Fractures or dislocations of cartilaginous pyramid Open Reduction Techniques—When extensive fractures occur or open lacerations provide ample exposure, bone or cartilage grafting often is necessary to restore nasal height. An open rhinoplasty approach might be necessary for reduction. With an open approach, the fragments can be accurately reduced and fixed with No. 30 or 32 wires or, more commonly, with 1.0-mm plates and screw fixation. If nasal height or length is lost, bone or cartilage grafting should be used and can be fixed with Kirschner wires or preferably with plates. If cartilaginous structures are separated from the bone, they can be fixed with clear nylon sutures. Open reduction usually yields better results than does closed reduction. SRPS • Volume 11 • Issue R8 • 2015 A B C Figure 25. Stranc classification of displacement after nasal fractures. Frontal impact nasal fractures are classified by degrees of displacement, as are lateral fractures. A, Plane I frontal impact nasal fractures: Only the distal ends of the nasal bones and the septum are injured. B, Plane II frontal impact nasal fractures: Injury is more extensive, involving the entire distal portion of the nasal bones and the frontal process of the maxilla at the piriform aperture. The septum is comminuted and begins to lose height. C, Plane III frontal impact nasal fractures: One or both frontal processes of the maxilla are involved, and the fracture extends to the frontal bone. These fractures are nasoethmoidal-orbital fractures because they involve the lower two-thirds of the medial orbital rim (central fragment of the nasoethmoidal-orbital fracture) and the bones of the nose. (Modified from Mathes.13) 33 SRPS • Volume 11 • Issue R8 • 2015 Closed Reduction Techniques—In principal, the nasal bone or septal fracture must first be completed and only then replaced into its proper position. The nasal bones are pushed superiorly and fractured laterally on both sides and are then pushed into proper position with digital compression. Similarly, the septal fracture is completed and then repositioned in the midline. If the bones are comminuted or loose and tend to sink posteriorly after reduction, internal packing (commonly with Doyle nasal splints; Xomed, Jacksonville, FL) will help prevent collapse and external nasal splinting is added. 1)Bruising and ecchymosis with pigmentation of skin and eyelids In cases of plane II fractures, when collapse of the nasal structures occur after attempted reductions, a technique that is very useful is insertion of transnasal wiring through the cartilaginous septum with the aid of a spinal needle while retracting the nose anteriorly. The wires traverse the nose at the level of the piriform aperture and are pulled through an orthopaedic felt that is covered with Xeroform gauze (Covidien, Washington, DC). This semi-soft dressing is further compressed by a Supramid plastic plate or MEDPOR plate, through which the wires traverse. This technique controls the fracture in the anterior–posterior plane and prevents widening of the fractured nasal bones that would otherwise regress into their morbid wide position. 4)Bleeding usually occurs within the first 2 to 3 days after injury; rebleeding sometimes occurs 7 to 10 days after injury Timing of Treatment—In reality, most nasal fracture treatments are deferred until the edema has partially resolved but should be treated in 5 to 7 days. After 2 weeks, partial healing in malalignment has occurred. In fractures resulting in reduced volume, concentric scarring renders reduction more difficult. Osteotomies might be necessary at that stage.217 Acute open rhinoplasty usually results in resection of telescoped septum and osteotomies. Elective secondary rhinoplasty usually is preferable to obtain better results. The exception to this is treatment of NOE fractures for which early intervention is the rule. All patients should be warned that because of the chance of cartilage warping and scar contraction, the nose might change shape with time and secondary surgery might be necessary. 2)Septal hematoma, which develops between the mucoperichondrium and cartilage and results in septal perforation or fibrosis; organization of the hematoma can lead to thickening of the cartilage 3)Breathing obstruction can occur when severe septal deviation or thickening is present 5)Nasal growth retardation in children219,220 6)Soft-tissue infection can occur; some surgeons prescribe antibiotics for any nasal fracture Late Complications— 1)Septal thickening and airway obstruction; if untreated, septal hematoma can become organized, resulting in subperichondrial fibrosis and thickening; septum can become as thick as 1 cm and require sculpturing or resection; submucous resection of thickened portions of nasal septum, outfracturing turbinates, and partial resection of turbinates can help with obstruction 2)Synechiae can occur in areas of soft-tissue lacerations of septum and turbinates when tissues are in contact;221 treatment includes division and placement of splint or nonadherent gauze for 5 to 7 days until reepithelialization Complications 3)Obstruction secondary to malunion of nasal bones, telescoping, or lateral deviation of nasal septum can occur; if loss of soft tissue occurred during initial injury, scarring prevents simple reduction; excision of scar and grafting or insertion of flaps is necessary to attempt to prevent soft-tissue contracture Early Complications— 4)Residual osteitis or infection of bone 34 SRPS • Volume 11 • Issue R8 • 2015 or cartilage; secondary grafting can be performed after 6 months without evidence of infection 5)Chronic pain is infrequent and usually affects the external nasal branches222 6)Malunion of nasal fractures is common after closed reductions; palpation after reduction to confirm reduction is often inaccurate and external splints often fail to prevent deviation because of release of “interlocked stresses” after cartilage fracture223,224 7)Misdiagnosis of NOE fractures as nasal fractures is frequent and can result in severe deformity that is difficult to treat; telecanthus, loss of nasal height, and upward tilting of the caudal nose with subsequent contraction of the soft tissue create severe deformity that necessitates soft-tissue expansion by repeated grafting; initial correct diagnosis is most effective way to prevent this complication Midface (Maxillary) Fractures Definition The midface is considered to be the area between the lower orbital rim, alveolus, and maxillary dentition. The largest bony portion of the midface is the maxilla. Maxillary fractures are less common than mandibular, zygomatic, and nasal fractures.225 sufficient trauma, absorbing and dissipating the energy, thereby protecting the skull base and brain.232 The maxilla contributes to the formation of the midportion of the face and forms part of the orbit, nose, and palate. It has four processes: frontal, zygomatic, palatine, and alveolar. The frontal process provides anchorage to the nasal bones and cartilage and the medial canthal ligaments. The zygoma is stabilized by its articulation with the sphenoid, the frontal bone, and the temporal bone. The maxilla stabilizes the zygoma indirectly by stabilizing the surrounding facial bones to which the zygoma articulates. The maxilla is stabilized to the skull base via its anterior articulations, medially in the glabellar region to the frontal bone and nasal bones, laterally via its articulation to the zygoma, and posteriorly via the third vertical buttress, which is the pterygomaxillary buttress. The alveolar process of the maxilla is strong and thick and provides support for the teeth. It provides a strong horizontal buttress and protects the upper portion of the maxilla. As teeth are lost, the alveolar process thins, weaken, and resorbs.233 Most fractures of the maxilla result from direct impact. Their pattern depends on the magnitude and direction of the forces, whether frontal, lateral, or inferior impact.234 Muscle contraction plays a less important role in the displacement of bony fragments than its role with other types of fractures, including zygomatic fractures, which are Anatomy The maxilla consists of vertical, horizontal, and sagittal buttresses that are thick sections of bone capable of resisting considerable forces (Fig. 26).226 The vertical buttresses, considered the strongest, are the medial nasofrontal buttress, the lateral zygomaticmaxillary buttress, and the pterygomaxillary buttress posteriorly.227,228 Overall, the maxilla is designed to absorb forces of mastication and provide strong vertical buttress for the occluding teeth of the mandible.229 Via the buttress system, the load is distributed over the entire craniofacial skeleton.230,231 The midface collapses with Figure 26. Vertical buttresses of midfacial skeleton. (Reprinted with permission from Manson et al.226) 35 SRPS • Volume 11 • Issue R8 • 2015 under the immense pull of the masseter muscle.226 The muscles of facial expression anteriorly and the pterygoid muscles posteriorly are weaker but can influence the direction of the maxillary fragments, as seen with sagittal fracture of the maxilla,235 a fracture that splits the palate in the anterior−posterior direction and pulls the segments laterally.236 Classification The buttresses of the maxilla are comprised of thick strong bones. The remainder of the maxilla is made of thin weaker bones through which fracture lines occur. Usually, the fracture lines travel adjacent to the thicker portions of the bones. Le Fort clarified the areas of weakness in the maxilla and designated them as the line of weakness.237 Between the areas of weakness are areas of strength. Based on his experimentations, Le Fort developed a classification of midfacial fractures. The Le Fort level I, II, and III fracture patterns are based on the highest level and components of the fracture on each side. In reality, most fractures are not pure bilateral fractures but rather permutations and combinations of these fractures. It is more common to observe different levels of fractures on each side than exactly similar fractures on both sides.238 Manson238 further classified Le Fort fractures to include a fourth level Le Fort fracture that includes the frontal bone. Manson added two elements to the classification that can be associated with midface fractures: first, the pattern of fragment that includes the maxillary dentition; second, associated fractures of the mandible, NOE, and frontal sinus. For the student who is getting acquainted with the Le Fort classification of midface fractures, there is no substitute for reviewing a pictorial of the fracture patterns in conjunction with a real or model skull inclusive of the cranium (Fig. 27). It also is helpful to remember that all Le Fort level fractures have one thing in common: all involve fractures through the pterygoid plates. Le Fort Level I Fracture or Transverse (Guerin) Fractures— Le Fort level I fractures are transverse fractures that can traverse across the maxilla at different levels ranging from the base of the maxillary sinus to beneath the orbital rim. They usually occur bilaterally and most commonly traverse at the base of the maxillary sinus and the inferior margin 36 of the piriform aperture. They can be higher and cross just beneath the zygoma and at times reach just under the inferior orbital rims, thus creating a pattern very similar to that seen in a low Le Fort level II fracture or a high Le Fort level I osteotomy. Le Fort Level II Fractures or Pyramidal Fractures—Le Fort level II fractures occur with blows to the central maxilla, especially involving a frontal blow. The fracture begins above the level of the apices of the maxillary teeth laterally and posteriorly in the zygomaticmaxillary buttress, extending through the pterygoid plates. Medially, the fracture line travels superiorly to cross through the medial portion of the inferior orbital rim, extending across the nose. The level of fracture through the nose varies greatly and crosses at a high level across the junction of the nasal bones and the frontal bones (high Le Fort level II fracture), through the mid nose, or through the nasal cartilage (low Le Fort level II fracture). Damage to the ethmoid region is common via the fracture at the medial orbit, and lacrimal system injury can occur if the fracture line traverses the lacrimal fossa. With higher energy impact, fractures include a combination of Le Fort level I and level II fractures, with or without a split palate.235,239 Le Fort Level III Fractures or Craniofacial Disjunction— When fractures extend laterally through the zygomatic arch, zygomatic frontal suture, and orbital floor and medially through the medial orbital rim and nose, the midface is disconnected from the cranium. Occasionally, the midface fracture is a large single fragment, which is only slightly displaced or immobile.225 These fractures might be only minimally displaced and present with “black eyes” and with subtle malocclusion. In these scenarios, the midface is incompletely detached from the base of the skull and suspended by soft tissue and a greenstick fracture.240 Le Fort Fracture Treatment From the time Le Fort fractures were first described in the 1900s by French orthopaedic surgeon Rene Le Fort237 through the period in which these fractures were treated with open reduction of the midface fractures and internal fixation with wires suspended to the upper face, as advocated by Adams in 1942198 and 1956,199 the treatment of midface fractures changed significantly. Advances in the last 25 years have been achieved, including the aesthetic SRPS • Volume 11 • Issue R8 • 2015 I II III Figure 27. Le Fort classification. aspects of fracture treatment.38,241−246 The reasons for this development can be summarized as follows: 1)The increased use of CT scans with fine delineation of the bony and soft-tissue injuries 2)The use of wide exposure of all fractures as opposed to previously advocated limited exposures 3)Open reduction and rigid internal fixation techniques with improved implant materials with use of plates and screws instead of wires, allowing three-dimensional stabilization 4)Immediate bone grafting to replace or augment unusable bone fragments as pioneered by Gruss et al.247 Goals of Le Fort Fracture Treatment Several important goals should be achieved with the treatment of midfacial fractures: 1)Reestablish midfacial height and width.238 2)Reestablish occlusion. 3)Restore the nose and orbit. 4)Restore the bony midface between the buttresses to provide proper soft-tissue support and contour. The untreated midface tends to be elongated and retruded. The most common complication of the treated midface, as originally described by Ferraro and Berggren,248 is reduced midfacial height and projection. Therefore, to restore midface height and projection, it is key to restore the facial buttresses to their anatomic positions. Anteriorly, the nasomaxillary and zygomatic maxillary buttresses should be reduced and reconstructed with bone grafts if needed. Fixation should then be applied. The posterior pterygomaxillary buttress is not reconstructed but rather reduced by means of IMF. If the mandibular condyle and ramus, which constitute the posterior sagittal buttress and provide facial height, are intact, IMF to the anatomically stable mandible provides a guide to correctly achieve posterior height of the midface. If the mandibular ramus or condyle is fractured, ORIF must be achieved before treating the midface. Otherwise, the risk of midfacial height malposition is high. The same problem can occur if a sagittally split palate is undiagnosed, resulting in midfacial lower height, increased width, and malocclusion.235,236 37 SRPS • Volume 11 • Issue R8 • 2015 Vertical or Sagittal Fractures Vertical or sagittal fractures are less common fractures that traverse the maxilla vertically and separate the segments in a sagittal anteroposterior plane.235 These fractures traverse the alveolus and the palate with different patterns that are mostly associated with Le Fort level I fractures but are also seen with Le Fort level II fractures (Fig. 28).236 They often occur at the junction of the maxilla and the vomer.249 Fifty percent of these fractures are associated with other maxillary fractures.250 When these types of fractures are present, treatment of the Le Fort fracture is more complicated and can be complicated by facial and dental arch width problems in addition to vertical and anterior or posterior displacement.251 Diagnosis History—The most common causes of Le Fort fractures are frontal and lateral impacts. Most commonly, the patient is thrown anteriorly onto a dashboard, steering wheel, or other object. A maxillary fracture can occur from upward trauma to the face exerting force to the midface via the mandible.68,252 Displacement of the maxilla usually is posterior and inferior because of the pull of the pterygoid muscles. Midfacial elongation is seen. The maxillary occlusal fragments tilt downward, creating an anterior open bite, often more prominent on one side than the other. Impacted maxillary fractures occur, although less frequently. The maxilla can be so impacted into the interorbital space or pharyngeal space that mobility is not noticed during physical examination.240 Most Le Fort fractures have evidence of bilateral maxillary sinus fluid and malocclusion. Upper level Le Fort fractures have bilateral periorbital ecchymosis. Physical Examination—Malocclusion is the one most sensitive physical finding that suggests midface fracture. Yet the hallmark of midfacial fracture is mobility of the maxillary dentition, if it occurs. Not all midfacial fractures demonstrate mobility of the maxillary segment. Incomplete fractures (greenstick fractures) or singlefragment Le Fort level I fractures without comminution can be diagnosed only by bilateral periorbital ecchymosis and minor malocclusion. Rowe and Killey225 thought that these rare fractures occur in 5% of the cases. 38 Demonstration of bilateral bimaxillary sinus fluid is the most reliable CT finding considering that fracture lines often cannot be seen on the scans. Additional findings of epistaxis, periorbital ecchymosis, facial edema, and subcutaneous hematomas are suggestive of maxillary bone fractures. Because the maxillary segment usually is displaced posteriorly and inferiorly, class three malocclusion and anterior open bite are observed. Intraoral digital examination can reveal soft-tissue tears of the labial vestibule or the palate, indicating alveolar or palatal fracture. After several days, the face might look elongated and retruded. If the zygoma laterally is lower than the maxilla medially, zygoma fracture is suggested. If the maxilla is lower, maxillary fracture is suggested. If nasal mobility is felt, Le Fort level II or III fracture is present because the nose is always involved in these two fractures. During examination, maxillary motion is assessed by holding the forehead with one hand and the maxilla and palate with the other and moving the maxilla. As noted previously, with high Le Fort level III fractures, greenstick fractures might not be discernible. Therefore, even malocclusion, to which patients are highly sensitive, might not always be confirmed by the patient at the time of injury. Occlusion has to be closely examined by the physician, considering wear facets and occasionally needing previous dental records to assess whether the patient had pre-injury malocclusion. CSF might leak from the middle or anterior cranial fossa in high Le Fort fractures and is then apparent in the nose or ear canal.70,253 Radiographic Examination—CT scan of the maxillae from the palate to the cranial fossa is the examination of choice for midfacial fractures. Axial and true coronal views are preferred, but axial views and coronal reconstruction usually are adequate.227,254 Non-displaced or minimally displaced fractures often are difficult to see, even on CT scans, but bilateral fluid collections in the maxillary sinus are always seen with maxillary fractures. Treatment Treatment of midfacial trauma should be approached as any other trauma per the Advanced Trauma Life Support Manual.255 After the airway is secured and hemorrhage controlled, soft-tissue lacerations should be closed and SRPS • Volume 11 • Issue R8 • 2015 Figure 28. Above left, Type 1 posterolateral alveolar fracture. Above center, Midline sagittal palatal fracture in a child. Above right, Paramedian-sagittal palatal fracture. Below left, Para-alveolar sagittal fracture. Below center, Palatal fracture of complex pattern. Below right, Transverse palatal fracture. (Reprinted with permission from Hendrickson et al.236) IMF applied. The latter procedure is the single most important treatment of maxillary fracture.226 IMF can be accomplished at bedside under local analgesia if any delay occurs in bringing the patient to the operating room. Performing open reduction and internal fixation (ORIF) is the gold standard of treatment of any facial fracture, but soft-tissue closure and repositioning are equally important. Two steps must be performed with soft-tissue closure: 1) closure of skin, muscle, fascia, and periosteum at the incisional areas; and 2) fixation of the fascia or periosteum to the skeleton. By doing these simple maneuvers, soft-tissue descent and irreversible retraction of the soft tissue can be prevented. Principles of bony repair are proper exposure, reduction, and internal fixation. In any subunit of the face, the most important dimension to restore is facial width. Bony reduction and fixation must be accurate because they allow correct draping of the soft tissue. If this is not done immediately, the soft tissue develops internal scarring (or “memory”), creating irreversible internal deformity and thickness. A unique property of the midface is the thinness of its bone. The midface therefore can be considered a “dependent” structure.256 Because of the thin bones of the midface, plating cannot be considered rigid fixation but rather a positioning technique. Additionally, with current midface repair techniques, the only relatively strong sagittal buttress that is not addressed is the pterygoid buttress. Therefore, the midface must be guided in its reduction by a clear anatomically correct structure, usually the mandible. If the lower midface, considered the area below the Le Fort level I fracture line, is guided by the upper midface, which has weak sagittal support, severe facial deformities, such as lack of projection, enophthalmos, malocclusion, or increased facial width, can occur ensued by soft-tissue deformities, such as descent, diastasis, fat atrophy, thickening, and rigidity of skin. IMF in proper occlusion is the single most important maneuver in treating midfacial fractures, and its importance cannot 39 SRPS • Volume 11 • Issue R8 • 2015 be overemphasized.227,257 It is simple and can be performed nearly in any situation, even at the patient’s bedside if necessary. Because of the tendency of the mandible musculature to be in a rest position, close to centric rest, fixating the midface to the mandible repositions it in a near anatomic position and corrects the midface retrusion and elongation. Applying the IMF reduces fragment distraction, often helps with control of bleeding, and places the maxilla at rest. Alveolar Fractures Most alveolar fractures can be digitally repositioned and held in reduction while arch bars are applied. For additional stability, the arch bar can be acrylated. If the alveolar segments cannot be adequately reduced manually or if premature contact occurs between the teeth of the maxilla and the mandible, ORIF usually is necessary. The reason is usually an incomplete fracture or intervening soft issue within the fracture line. In these cases, fixation is performed with monocortical screws in addition to IMF. Fixation should be maintained for at least 4 to 12 weeks or until clinical immobility is achieved.235 The teeth in the alveolar segment often are insensate because of damage to neurovascular structures within the pulp and require proper endodontic evaluation. Palatal Fractures Fractures of the midface are seldom symmetrical, and segmental fractures of the alveolus and palate are common. Several classification schemes of fractures of the edentulous maxilla have been suggested for palatal fractures.236,251,256 Hendrickson et al.236 described six types of palatal fracture (Fig. 28) as follows: Type I, anterior and posterolateral alveolar large individual segments and no comminution. After rigid internal fixation is applied, increased stability often is obtained such that the palatal splint can be eliminated. If the fractures cannot be adequately reduced and rigidly aligned, they are managed with palatal splints. The authors stated, “…splints are necessary for all complex fractures and for some large segment fractures to provide further occlusal alignment.” They also reported that for comminuted fractures, the use of a splint is not only indicated but is the easiest method of providing vault stabilization. Care must be taken not to devascularize the buccal, gingival, or palatal mucosa during exposure of the fracture (Fig. 29).236 Full open reduction must include reduction and stabilization of the palatal vault, the dental arch (alveolus or piriform aperture), and the four anterior vertical buttresses of the maxilla (Fig. 30).236 Park and Ock251 also developed a classification scheme for palatal fractures that is based on anatomic location of the fracture line and related treatment plans (Table 2). The authors found that closed reduction and immobilization for 4 to 6 weeks often is adequate treatment for alveolar fractures. All other fractures of the palate are treated with open reduction and rigid internal fixation followed by IMF for 2 to 6 weeks. The authors used an acrylic palatal splint to check occlusion before and after rigid fixation. Intraoral splints can be useful adjuncts to midfacial fracture reduction and immobilization. They range from the simple type that helps stabilize an isolated alveolar ridge fracture, to sophisticated palatal and Gunning splints used with complex or comminuted fractures of the maxilla. Unfortunately, in the acute trauma setting, it might be difficult to compensate for the fracture lines on the dental model, with a resulting ill-fitting splint (Fig. 31).235 The trend in palatal fracture management, as voiced by both Manson et al.235 and Park and Ock,251 is toward wide exposure with ORIF, using splints only when needed to supplement the fixation. Type II, sagittal Type III, parasagittal Type IV, para alveolar Type V, complex Type VI, transverse The authors reported that fractures selected for internal fixation are oriented anteriorly to posteriorly and have 40 Fractures of the Edentulous Maxilla Fractures of the edentulous maxilla are less common and usually are associated with additional extensive fractures of the middle facial bones.233,258,259 The absence of teeth, which usually transmit the forces to the maxilla, can decrease the chance for bony disruption. The presence of dentures can decrease the energy transmitted to the maxillae by fracturing first. SRPS • Volume 11 • Issue R8 • 2015 If the fracture does not cause facial deformity, adjusting or remaking the dentures can correct any slight discrepancy in the occlusion. In cases in which a significant facial deformity or occlusal discrepancy will occur if the fracture remains non-reduced, ORIF should be performed with a plating system. In cases in which comminution is so severe that accurate reduction Figure 29. Above, Incisions for palatal fracture treatment must be carefully designed. In some cases, the traditional transvesre vestibular maxillary incision (dotted line) should be reoriented vertically (dashed line) to prevent devascularization of the inferior gingival mucosa. Below, In the absence of a vault laceration, incisions in the palatal vault should be longitudinal and should avoid the area of the greater palatine artery, which travels anteroposteriorly just above the palatal mucoperiosteum. The dotted area represents the safe region. (Reprinted with permission from Hendrickson et al.236) is difficult, dentures or splints can be designed to enable IMF to the stable and anatomically positioned mandible. For quick fixation of the dentures, they can be screwed into thicker alveolar bone, if present, to assist in IMF but should be removed after reduction and fixation before making new dentures. Figure 30. Above, the plan for fixation of the maxillary alveolus involves palatal vault and piriform aperture or alveolar plating plus buttress reconstruction. Below, the buttresses of the fractures maxilla and palate include a transverse (circumferential) buttress across the palatal vault, a circumferential buttress across the alveolar ridge, and the six vertical buttresses of the maxilla. With traditional maxillary fracture open reduction techniques, only the four anterior buttresses—the naso-maxillary and zygomatoicomaxillary buttresses (solid vertical lines)—are stabilized. The posteror buttress—the pterygo-maxillary buttress (dotted vertical lines)— is not routinely stabilized. (Reprinted with permission from Hendrickson et al.236) 41 SRPS • Volume 11 • Issue R8 • 2015 Table 2 Classification and Suggested Treatment of Palatal Fractures251 Treatment Immobilization (weeks) Exposure and Rigid Fixation Corresponding Fracture Type per Hendrickson Classification236 Anterior Surface Palatal Surface Closed reduction - - 4-6 Alveolar Anterior + - 2-3 Alveolar, para-alveolar, transverse Anterior and palatal + + 2-3 Sagittal, parasagittal Combined + +/- 4-6 Para-alveolar, complex, transverse Early Complications Hemorrhage—Extensive hemorrhage can occur in association with fractures of the midface. Management might involve the following techniques: 1)Identification of the bleeding vessel and ligation 2)Tamponade by direct pressure, packing, or, most often, by manual reduction of fractures; reduction into IMF 3)Angiographic embolization 4)Ligation of external carotid or superficial temporal artery Airway Obstruction—With most large midface fractures, posterior displacement of the maxillae is combined with swelling of the soft tissues of the nasal, oral, and pharyngeal cavities, leading to partial compromise of the airway. Simple maneuvers, such as sitting the patient in bed and manually reducing large segments, might prevent the need for emergency airway protection but often nasotracheal, endotracheal, or tracheal intubations are necessary for airway protection. 42 Figure 31. Acrylic splint helps stabilize fractured palate after reduction and fixation with intermaxillary elastics. A small wire coapts the segments at the posterior margin of the bone palate. (Reprinted with permission from Manson et al.235) SRPS • Volume 11 • Issue R8 • 2015 Infection—Maxillary infections are less common than mandibular infections.260 Despite the bony fragments that often are pushed into the surrounding sinuses, infection is not common. Infections more commonly occur if the sinuses are diseased or persistent occlusion of the sinus orifices occur as a result of displaced bone or blood clots. If infection does occur, treatment includes removal of devitalized tissue and bone, opening of occluded sinuses, removal of foreign material, and antibiotic treatment based on culture sensitivities and specificities. Lacrimal Obstruction—Lacrimal duct obstruction can lead to dacryocystitis and require external drainage.261 Infection can spread into orbital soft tissue, leading to increased orbital pressure and subsequent blindness.260 CSF Rhinorrhea—CSF rhinorrhea occurs more commonly in association with Le Fort level II or III fractures that involve the cribriform plate. The role of antibiotics is unclear, and antibiotics should be administered for 48 hours after reduction. Long-term prophylactic antibiotics should be avoided to avoid selecting resistant strains. Also, nasal packing and blowing the nose should be avoided to avoid obstruction or backflow of infected nasal content into the meninges. Blindness—Blindness is a rare complication that occurs more often in association with Le Fort level II or III fractures. The common reason is compression of the optic nerve or decrease in its capillary blood supply as it traverses the narrow optic canal rather than optic nerve transection. Late Complications Because many complex maxillary fractures, especially Le Fort level I and II fractures, involve the orbit or malar complex, late complications in these areas are discussed separately in their respective sections. Nonunion—Nonunion of the maxilla is rare100,262 and usually is a consequence of complete neglect or failure to provide any basic type of IMF or open reduction. If nonunion is diagnosed, the approach must include complete exposure of the fracture, removal of all fibrous tissue at the fracture site, reduction of the remaining bony segments, removal of bony proliferation, replacement of the bony gaps with bone grafts, and “rigid” fixation of the fracture with plates and screws.133,263,264 The term rigid is used guardedly considering complete stable fixation with the thin bones of the maxilla is not possible. With this approach, healing is nearly almost the rule. It is essential to bone graft gaps that are larger than 3 to 5 mm in the buttress system265,266 and over the anterior maxillary wall, which strengthens the repair and prevents prolapse of soft tissue into the sinus. Malunion—The maxilla usually heals in within 6 to 8 weeks after the fracture or after fracture repair. Patients suffering from comminuted fractures must be watched for an additional 4 to 5 weeks on a weekly basis to ensure the patient has not moved out of occlusion. If the patient continues to demonstrate mobility of the maxillae, it will usually heal within 4 additional weeks. Close observation is necessary on a weekly basis after IMF is released to verify that occlusion is maintained. If deviation of the occlusion occurs, the first sign usually is an anterior open bite with lack of cuspid contact. Once this is noticed, elastic traction should be initiated. After 4 weeks of stable correct occlusion, the arch bars can be removed. A soft-foods diet should be initiated with progression to a regular diet. Impacted fractures or fractures that are several weeks old might be impossible to reduce despite complete exposure of the fracture. Sometimes application of IMF with elastic bands reduces the fractures.100 In most cases, an osteotomy is required to obtain the necessary reduction and has been shown to be a safe and efficient technique.260 Reduction with Rowe disimpaction forceps is less desirable, especially at Le Fort levels II and III, because of an increased risk of adding fracture lines including into the orbital apex, resulting in blindness.267 If malocclusion occurs secondary to malunion at Le Fort level I, gingivobuccal incisions are made and osteotomies performed. Pterygomaxillary dysjunction might be necessary to mobilize the segment. Increased posterior maxillary height with normal or shortened anterior maxillae is a problem that sometimes occurs. In such cases, resection of the posterior maxillae and portions of the pterygoid plates is necessary. Bone grafting where bony gaps are present, especially at the buttresses, often is essential. 43 SRPS • Volume 11 • Issue R8 • 2015 In cases of malunion at Le Fort level II or III, exposure is obtained via incisions in the gingivobuccal area, appropriate lid incisions, and coronal incisions, which are necessary. After proper exposure, osteotomies, and mobilization, bone grafts often are necessary. Plate Exposure—Plates and screws often are exposed after repair of fractures, more often at Le Fort level I.268 Screws can migrate,205 and plates placed in the alveolus of edentulous fractures might not permit comfortable wearing of dentures and thus require removal. Nasolacrimal Duct Injury—Transections or obstruction of the nasolacrimal duct can occur in midfacial fractures between Le Fort level I and Le Fort level III.86,269 When the canalicular system is intact in the canalicular portion but is obstructed by bony displacement or proliferation, dacryocystorhinostomy is indicated.270 With Le Fort level II and III fractures associated with NOE fractures, the nasolacrimal sac or duct might be blocked by displaced bone at the orbital rim level. Anatomic reduction of the bone usually is the most effective maneuver to avoid these problems, but if occlusion occurs, initial external drainage and then secondary dacryocystorhinostomy are necessary.271 of the three areas are termed panfacial fractures (Fig. 32).13 With panfacial fractures, various areas of the facial skeleton are involved.241,242,246,272 Each area can be treated by applying the techniques previously described to achieve anatomic structural integrity of the facial skeleton. The most common mechanism of injury for these fractures is high-velocity motor vehicle collision, although the fractures occur less commonly since the advent of air bags. These facial injuries typically occur concomitantly with multi-organ system traumatic injuries, and patients are therefore often in critical condition. Timing of Treatment Regardless of the severity of the injuries, cutaneous wounds can be irrigated, debrided, and closed and IMF can be applied. This initial urgent treatment is the minimum that should be administered in cases of mandibular or maxillary injuries. In cases of mandibular fractures, dental impressions can help with planning, old dental records should be obtained, and pre-trauma photos can assist with assessing the premorbid facial dimensions of width, projection, and height. These elements also provide clues regarding pre-injury occlusion. Extraocular Muscle Injury—Extraocular muscle injury can occur as a result of contusion during the initial injury or from surgical dissection. These injuries are more common in midface fractures involving the orbit, NOE, and ZMC. Malpositioning of the globe can occur after repair of such fractures, with malproper alignment of the orbital rim or walls. Orbital enlargement with subsequent enophthalmos is also seen after treatment of NOE fractures, zygomaticmaxillary fractures, and orbital fractures, as discussed in previous related sections. Pan Facial Fractures Definition Panfacial fractures are fractures that involve the upper, middle, and lower portions of the face: the frontal bone, maxillae, and mandible. In reality, fractures involving two 44 Figure 32. Panfacial fractures. (Modified from Mathes.13) SRPS • Volume 11 • Issue R8 • 2015 Perhaps the most important aspect in the treatment of these fractures is understanding the role of the overlying soft tissue in the pathomechanics of the injuries. The soft tissue in facial trauma, especially in panfacial trauma, is severely contused and suffused with blood. The soft tissue tends to scar quickly and to assume the shape of the underlying malreduced or malaligned bones. The soft tissue develops internal thickening, rigidity, and memory that render it nearly impossible to restructure it to its original shape. Only early treatment of the underlying bone can obtain correct draping of the soft tissue envelope. Thus, contraindications for immediate definitive management are few. The contraindications include: 1)Uncontrolled intracranial pressure (>20 mmHg) 2)Acute hemorrhage with depleted clotting factors, as observed with large pelvic fractures or massive intraabdominal bleeds 3)Coagulopathy, as evidenced with severe central nervous system injuries 4)Acute respiratory distress syndrome Coma without associated intracranial hypertension, mechanical ventilation, or other organ injuries is not a contraindication for immediate treatment of facial fractures. In comatose patients, CT scans of the head can be obtained and intraoperative intracranial monitoring can be conducted. Initial physiological resuscitation and stabilization are essential first steps. Further diagnostic workup includes CT scanning of the face. Based on the types of injury, several specialists need to be involved in the surgical planning, including neurosurgeons and ophthalmologists. Treatment The optimal timing for intervention is within a few hours after injury before edema and soft-tissue rigidity begin. This is not always possible if other injuries that take priority occur, such as life-threatening injuries and neurosurgical and ophthalmological emergencies. Onestage skeletal reconstruction to anatomic position is the current preferred method of treatment.242 The incisional approaches are the same as those described in previous sections based on the anatomic area of injury. The coronal incision allows access to the frontal sinus, superior orbital rims, orbital roof, lateral orbit, NOE complex, and upper nose. Lid incisions allow access to the orbital floor and inferior orbital rim, and the gingivobuccal incisions allow approach to the maxilla. The lower gingival and retromandibular incisions provide approach to most mandibular fractures. Because the fractures are in a three-dimensional plane and the surgeon cannot see all the fractures at one time, use of temporary wiring might help with initial positioning until plates and screws are applied. Although previously noted, it cannot be overemphasized: bone grafts are essential for healing and stability in cases of substantial bone gaps (>3−5 mm), especially when reconstructing the structural buttresses of the face.265 If dental alveolar process is missing, a dental splint with an occlusal stop often is necessary to provide stability to the IMF, provide soft-tissue support, and provide correct facial height. Many sequences for treatment of panfacial fractures have been described: top to bottom, bottom to top, outside in, and inside out. Forrest and Antonyshyn273 presented an algorithm for repair of complex fractures of the midface. Gruss and colleagues57,75,274,275 stated that the zygomatic arch is the key area in midfacial fractures that should be reduced and stabilized first to reestablish the pre-traumatic facial width and to prevent further lateral spread. Glassman et al.276 preferred starting from the NOE region proceeding laterally and emphasized that there is no one correct approach. As long as anatomic reduction is safely and correctly achieved, the approach and sequence are less important. Following is the order of reconstruction of panfacial fractures per Glassman et al.276: 1)Place the mandible and maxillae in IMF with arch bars. 2)If the palate is split or the mandible has fractures in the horizontal plane, these fractures should be reduced and plated before proceeding to IMF. The arch bar then acts as a tension band. 3)In alveolar, palatal, and mandibular fractures, impression and model surgery 45 SRPS • Volume 11 • Issue R8 • 2015 assist in putting the mandible and maxillae in the proper arch form. 4)For angle, body, parasymphyseal, and symphyseal fractures of the mandible, intraoral incisions usually suffice for access. 5)For severely comminuted mandibular fractures of the body or angle or condylar fractures, external open approaches usually are preferred. Wires can be used for temporary fixation until alignement is achieved, and rigid fixation can then be applied. 6)Before proceeding to mandibular reduction and fixation in cases of combined midface and mandibular fractures, the maxillary arch should be anatomically reconstructed and can serve as a guide to the mandible. If the palate or alveolus is fractured, it must be reduced and rigidly fixed. A splint can act as an occlusal stop or provide additional stability for patients with highly comminuted fractures or missing bones. Once the dental arch is stable, it serves as a guide for mandibular width, dental inclination, and occlusal position. The mandible is approached as described in items 4 and 5, based on the fracture pattern. If larger bone gaps occur, the reduction might need external fixation or a 2.4-mm reconstruction plate can be used to bridge the gap until final reconstruction with bone and soft tissue, if needed, is performed. The basal portion of the mandible usually is reconstructed first, and then ORIF of the ramus is performed via Risdon, preauricular, or retromandibular incisions or a combination of incisions in cases of severely comminuted ramal fractures when better exposure is required. The reduction should be performed when the mandible is in IMF. Once reduction is completed, the IMF should be released and the occlusion checked while the condyles are carefully seated in the fossa by finger pressure. 7)The coronal incision is used for exposure 46 of the frontal sinus, superior orbital rims, zygomatic frontal process, medial and lateral orbital walls, zygomatic arch, and the NOE complex area. Glassman et al.276 preferred reducing the nasoethmoid area first and then aligns the zygoma to the medial maxilla. Anatomic position of the zygoma is best determined by inspecting alignment of the lateral orbital wall at the suture of the orbital process of the zygoma to the greater wing of the sphenoid. One should remember that the arch is straight rather than “arched.” 8)The orbital floor should be reconstructed anatomically. A small ledge of bone usually is present in the posterior orbital floor, as far back as 35 to 38 mm. This bony ledge serves as a guide for the angle and slope of the bone graft or reconstruction plate. Preformed reconstruction plates are also available from different companies. The orbital rim is reconstructed with 1.0- to 1.3mm plates and should be flat, not curved inferiorly. 9)The nasoethmoid region should be reduced and fixed with transnasal wiring and rigid fixation. 10)The medial and lateral orbital wall can be approached via the coronal approach if a coronal incision is made and either bone grafted or plated with titanium plates or MEDPOR.276,277 11)Before fixation at Le Fort level I, the mandible must be reconstructed. It is essential that the ramus height and anterior projection be reconstructed anatomically. If they are fractured, ORIF should be performed. Before applying the IMF, it is crucial to verify that the condylar heads are sitting in the glenoid fossas. Only then is IMF applied. Once IMF is achieved, reduction and fixation of the nasoethmoidal and zygomatic areas are completed. At this stage, fixation of the upper and midface is performed at the nasomaxillary and SRPS • Volume 11 • Issue R8 • 2015 zygomaticomaxillary buttresses on both sides. In severe cases in which the height of the buttresses is difficult to assess and reconstruct because of loss of bone, the lip-tooth position can be used as a guide for buttress height reconstruction. 12)Soft-tissue repositioning is key to successful restoration of premorbid appearance. Successful ORIF is not sufficient. If the soft tissue is not fixed to its presurgical position, soft-tissue ptosis will result. Closure must include the periosteum over the zygomatic frontal suture, attaching the orbital periosteum to the temporalis fascia and the malar periosteum to the inferior orbital rim, and closure of the muscle layers at the gingivobuccal incisions. Marking the periosteal layers during the inferior orbital rim incisions helps resuspend them anatomically after bony reduction is completed. If the mentalis muscle is degloved, it should be repositioned at its original position or else lower lip ectropion can ensue. Correcting soft-tissue descent is much more difficult secondarily and results in worse outcomes versus performing it correctly the first time. Complications Complications in treatment of panfacial fractures include those of the bones and soft tissue. 1)Instability of fixation in micro-fractures: Because of the small size and thin bone of the microsegment, the inserted screws can pull out, resulting in deviation and malreduction. 2)Unstable reduction or malreduction of the mandible can result in displacement of the maxillae. 3)Misplaced or malreduced condylar fractures can cause loss of height of the midface. If the mandible is adapted to impacted maxillae and the condyle is pulled anterior to the glenoid fossa during maxillomandibular fixation, the patient will drop into an open bite upon release of the MMF. 4)Soft-tissue ptosis can result from inadequate repositioning and reattachment of the fascial layers before closure of the skin. Despite the classic teaching of maximum exposure of fractures, the soft-tissue stripping can be kept to a minimum in certain cases in which exposure is sufficient. Gunshot Wounds to the Face Definition and Pathomechanism Gunshot wounds to the face involve ballistic injuries of different energy intensities and different levels of loss of soft tissue and bone.278 The degree of injury depends on the energy transferred to the tissue, which correlates to the mass and speed of the projectile. Additional factors that affect the degree of injury are area of contact, trajectory of the missile, tumbling, soft-tissue drag, tissue density, and soft-tissue penetration. For a more in-depth explanation of the mechanisms of injury, one should read the review of common misconceptions in wound ballistics presented by Fackler.279 Hollier at al.280 presented a review of 121 patients with facial gunshot wounds. Multiple gunshot wounds to the face occurred in one-third of the patients. The overall mortality rate was 11%. Two-thirds had skeletal injury, and three-fourths required surgery. Onefifth of the patients had intracranial injury, half of which required surgery. Classification Ballistic injuries can be divided into low-, medium-, and high-energy injuries.281,282 Low-energy ballistic injuries usually result from civilian handgun gunshot wounds and include both soft-tissue and bone injuries with little loss of those components. Conversely, medium- and high-energy ballistic injuries usually result from military or hunting rifles or shotguns and include substantial soft-tissue and bone injury with loss of those components. Each group of ballistic injuries is divided into four types based on the anatomic location of the injury and the degree of softtissue and bone injuries and loss (Fig. 33).283 47 SRPS • Volume 11 • Issue R8 • 2015 Low-Velocity Injuries Low-velocity ballistic injuries usually do not result in a substantial amount of soft-tissue or bone loss. The majority of the soft-tissue injury is within the path of the projectile. Conceptually, the majority of these injuries can be treated as facial fractures with overlying soft-tissue lacerations and thus should be treated primarily with reduction and internal fixation and, if necessary, primary bone grafting, especially of the upper face, with repair of the overlying soft tissue. Based on the study of ballistic injuries conducted by Manson,238 four anatomic injury types were recognized and are the basis for the following classification. Type I (Lower Face) Injuries of this type usually involve the tongue, floor of the mouth, and mandible. Figure 33. Four patterns of gunshot wounds of the face. Type I, lower facial wounds involving the mandibular area and tongue. Type II, injuries involving the lower midface and lower orbit. Type III, injuries characterized by involvement of the bilateral orbit and zygomatic and temporomandibular joint areas. Type IV, injuries involving the frontal bone and the orbit. Dashed lines, bullet tracks. (Reprinted with permission from Clark et al.283) Treatment Treatment of ballistic injuries to the face remains controversial. Some authors advocate delayed treatment, especially for patients in whom future rehabilitation might be difficult, as in cases of suicide attempts.284-286 Conversely, immediate reconstructions of the soft and bony tissues with second-look procedures have more recently been advocated.283,287 Immediate reconstruction of the bones and then immediate soft-tissue reconstruction provides both improved functional anesthetic results with shorter periods of disability and improved rehabilitation. When formulating a plan for treatment of gunshot wounds to the face, it is helpful to identify the entry and exit wounds, to identify the presumed path of the bullet, and to appreciate the mass and velocity of the projectile. Doing so can help predict the amount of soft-tissue and bone injury and the amount of soft-tissue and bone loss. 48 1)Approximately one-fourth of these patients develop marked edema that warrants consideration of either prolonged intubation or tracheostomy. 2)Soft-tissue loss generally is minimal with this type of injury. Débridement of the bullet track, including the entry and exit wounds, is recommended. Drainage of the neck, floor of the mouth, and ballistic track is necessary. 3)In the majority of these cases, the bony fragments of the mandible can be internally reduced and fixed. Ramus and condylar injuries should generally be treated with ORIF, with short periods of intra-maxillary fixation and early mobilization. 4)When a maxillary defect is present, primary bone grafting can be delayed for secondary procedures if the oral mucosa is not intact. Bone graft infections occur at a high percentage if oral communication exists. It is better to assure a surgically clean wound with intact oral mucosa before performing bone grafting. Vascularized bone flaps might be preferred, especially if the bone defect exceeds 4 cm. SRPS • Volume 11 • Issue R8 • 2015 Type II (Midface) Type IV (Craniofacial) Type II injuries involve the lower midface, including the maxillary alveolus, maxillary sinuses, and lower portion of the nose and zygoma. Type IV injuries are characterized by intracranial involvement. The supraorbital bones, orbital roofs, frontal bones, and frontal sinus are involved. Globe or optic nerve injuries are present in 40%, with blindness in 25%. 1)Some patients require only drainage of the maxillary sinuses. In others, ORIF of the zygoma or maxillary fractures is necessary. In cases of teeth or palatal injuries, palatal fistulae can be closed with local rotational flaps. 1)Exploration of the cranial base fractures often is needed with the assistance of the neurosurgical team. 2)In case of significant nasal oral swelling, airway management might be indicated. 2)Neurosurgical débridement of dural or cerebral lacerations with the repair of dural fistulae and elimination of frontal sinus function by mucosal stripping and burring of the walls is necessary. 3)With this type of injury, Le Fort fractures are not seen. 3)Immediate bone grafting of frontal bone should be performed. Type III (Orbital) Intermediate- and High-Velocity Injuries Type III injuries involve the orbital and nasoethmoidal complex. The contralateral temporomandibular joint (TMJ) often is involved. Intermediate- and high-velocity injuries usually involve both soft-tissue and bone loss. The primary goal of treatment is to achieve anatomic reduction of the bone and immediate soft-tissue coverage. Soft-tissue coverage can be obtained by approximating skin-to-skin, mucosa to mucosa, or mucosa to skin. This should be followed by serial débridement of soft tissue until all necrotic tissue, hematomas, and fluid collections are removed and drained. In most cases, the loss of bone and soft tissue is less than initially appreciated. With civilian casualties, most injuries occur from shotgun or high-energy rifle gunshot wounds and often are the result of suicide attempts. Close-range shotgun wounds usually result in extensive soft-tissue and bone loss. Hollier et al.280 described free tissue transfer as an early stage of treatment. 1)All bony injuries are best treated with open reduction and immediate bone grafting, if necessary. 2)Considering that damage to the globe occurs in almost 90% of cases, with bilateral blindness in 50% and unilateral blindness in 40%, careful ocular examination is imperative. 3)Lacrimal injuries occur in one-third of the patients, and disruption can be managed by primary simple intubation or repair of the lacrimal system, as described by Callahan.288 Secondary reconstruction might require dacryocystorhinostomy. 4)The TMJ can be treated by expiration and débridement, and if a small gap exists, it can be left and early mobilization permitted. If larger gaps exist, definitive reconstruction with a costal chondral graft covered by a vascularized temporal parietal flap with postoperative mobilization and elastic guidance is an option. The four types of intermediate- and high-velocity injuries are based on patterns of soft-tissue and bone loss. The extent of soft-tissue and bone injury usually far surpasses the area of soft-tissue and bone loss (Fig. 34).283 Type I (Central Lower Face) Type I injuries are characterized by injury to the central mandible, lower lip, upper lip, inferior nose, and midmaxilla, extending up to the orbit and at times involving the cranial base and causing cranial injury. They can also extend posteriorly to the posterior portion of the mandible. 49 SRPS • Volume 11 • Issue R8 • 2015 be addressed at a later procedure. 3)The maxillary and bony deficiencies should be addressed when soft-tissue coverage is obtained. In the interim, both the mandible and maxilla should be placed in anatomic positions and stabilized with a combination of rigid internal fixation or IMF throughout the period of soft-tissue and bone reconstruction to avoid malocclusion and the effects of concentric soft-tissue scarring. 4)Reconstruction of bony defects of the mandible or maxilla usually is obtained by applying free osteo-cutaneous flaps, such as fibular flaps, free iliac flaps, or any other osteo-cutaneous flaps. Type II (Lower Lateral Face) Figure 34. Four patterns of soft-tissue and bone loss (shaded areas) in shotgun injuries. I, Central mandibular and midface. II, Lateral mandibular. III, Maxillary and orbital. IV, Orbital and cranial. (Reprinted with permission from Clark et al.283) Type II shotgun injuries are the most commonly seen high-velocity ballistic injuries. They are characterized by soft-tissue and bone injuries in the lateral mandibular region. Treatment— Treatment— 1)Maxillary and mandibular bone loss generally occurs anteriorly and should be treated by external fixation or by plate and screw fixation in the anatomic position, reducing and stabilizing the bone defect. Plating and screws can be used whether coverage can be obtained acutely or secondarily. 2)Soft-tissue coverage often can be obtained primarily. This can be accomplished by approximating skin-to-skin, mucosa-tomucosa, or, when necessary, skin to mucosa. Serial débridement procedures usually are necessary, but after each débridement procedury, soft-tissue closure should be the goal. If closure of soft tissue causes lip shortening, nasal distortion, or distortion of any other facial structure, the distortion an 50 1)Primary closure of intraoral, skin, and soft-tissue defects should be attempted. Intraoral defects should be closed with nonabsorbable sutures. Skin defects usually can be closed by applying regional skin flaps, such as neck or cheek flaps. 2)If intraoral soft-tissue defects are not amenable to primary closure, for smaller defects, local tongue flaps can be used and for larger defects, free tissue transfer might be the choice. 3)Bone defects of the mandible should be addressed by anatomic reduction and either external or internal fixation. In case of very communited fractures, bone segments can be absorbed over time. Bone grafting should be performed only when mucosal continuity is achieved. In general, bone grafts are less reliable than free osteo-cutaneous flaps. SRPS • Volume 11 • Issue R8 • 2015 Type III (Midface) Type IV Injuries (Craniofacial) Type III defects involve the maxilla, zygoma, orbit, and maxillary sinus. The naso-ethmoid region is always involved. The unique aspect of these injuries is involvement of the maxillary sinus in the lack of sinus lining after the injury. High-velocity type IV ballistic injuries involve the upper third of the face. This involves the zygoma, orbit, globe, frontal bone, frontal sinus, and, occasionally, the NOE complex. They can also involve intracranial injury. Treatment— 1)In any situation in which primary closure of mucosa and skin can be achieved, bony reduction and fixation should be performed, including necessary bone grafting if indicated. This constitutes the best treatment plan. The major problem associated with these injuries is combined loss of maxillary lining and maxillary bone. If a substantial amount of maxillary lining of the sinuses is absent, the chances of successful bone grafting to an area of bone loss is low. Most bone grafts in these situations end up infected and necrotic and need to be removed. It is therefore necessary to either achieve continuity of the lining or obliterate the maxillary sinuses. Sinus obliteration can be performed by inserting a soft-tissue free flap, whether muscle or omentum, to obtain closure of the sinus and vascularized lining on which bone reconstruction can be performed. 2)In cases of substantial lining or bone loss of the maxillary sinus, bone reconstruction should in general be performed in a delayed fashion after sinus lining continuity is reestablished. In cases in which small sinus lining defects occur, the defects can be allowed to heal secondarily or attempted to be close primarily with permanent sutures. If skin and soft-tissue defects are closed under tension where there is no sinus lining continuity, the chances of skin breakdown are notable. 3)All bone fractures in the zone of injury where there is no bone loss should be reduced and fixed in the anatomic position. 1)In cases in which sufficient soft-tissue coverage or lining is present, primary reduction and fixation of the bones with possible bone grafting is indicated. Primary bone grafting is safe even when one-third of the orbital lining is compromised. Often times, the amount of bone and soft tissue loss is less than initially appreciated. In cases with substantial loss of lining or softtissue coverage, local flaps should be used for closure. Free flaps might be indicated. In such cases, bone grafts can safely be performed once the surgical site is clean and lining is available. Success rates of bone grafting in the middle and upper face are much higher than in the mandible. 2)In any case, bony reduction fixation should be performed even if serial débridement procedures are necessary. Bone grafting can proceed if soft-tissue coverage and lining are achieved or can be performed at a later stage after reconstruction of the soft-tissue envelope and lining. Mandibular Fractures Fractures of the mandible are common, and correct treatment to avoid long-term morbidity is paramount. Before the advent of rigid internal fixation, treatment of mandibular fractures was limited to closed techniques or open techniques with wire osteosynthesis. The trend toward open reduction and rigid internal fixation (plating) avoids maxillomandibular fixation and is supported by biomechanical and bone healing studies. Concepts in fracture management, specific patient populations, and the management of complications are herein reviewed. 51 SRPS • Volume 11 • Issue R8 • 2015 Surgical Anatomy The tooth-bearing portion consists of a thick, compact anterior border supporting a superiorly located alveolar process. The ascending ramus terminates in the coronoid process and condyle. The angle, ramus, coronoid process, and condyle are insertions for the muscles of mastication (Fig. 35). The condyle articulates with the cranium to form the TMJ, a compressed fibrous disc interposed between the mandibular condyle and articular fossa. Mandibular blood supply is two-fold: the inferior alveolar artery and the muscular attachments. The inferior alveolar artery arises from the mandibular portion of the maxillary artery. It descends between the sphenomandibular ligament and the mandibular ramus. It enters the mandibular foramen just below the lingula on the medial aspect of the ramus and courses inferiorly and laterally, traversing the body to exit via the mental foramen with the inferior alveolar nerve. Throughout the mandibular canal, the inferior alveolar artery sends numerous apical and periodontal branches. The major muscle groups of the lower face supply blood to the mandible through perforating periosteal arterioles. The inferior alveolar nerve innervates the mandible and mandibular teeth, paralleling the course of the inferior alveolar artery within the bone. The Angle classification of dental occlusion describes the relationship of the mesial buccal cusp of the maxillary first molar to the mesial buccal groove of the mandibular first molar (Fig. 36). Abnormal occlusal relationships are caused by skeletal deformities, malalignment of the teeth, or a combination of the two. border alternate compressive or tensile forces during the masticatory cycle, thus yielding an overall torsion effect. The TMJ functions by hinge and translational movement. Rotation about the center of the condyle occurs early during jaw opening, whereas sliding translational motion occurs later during wider opening as the condyle moves anteriorly and inferiorly along the articular eminence of the temporal fossa. Condyle Coronoid process Ramus Angle Body Symphysis Figure 35. Anatomic regions of the mandible. Figure 36. Angle classification of occlusal status. Class I, normal; Class II, mesial; Class III distal. Biomechanics An adequate soft-tissue envelope and appropriate functional loading are paramount for normal mandibular development. Deformation results when functional and dynamic forces, such as muscle contractions and chewing, place an unbalanced load on the mandible.289 Generally, tensile forces predominate along the alveolus and superior border and compressive forces act on the inferior border. Proximal to the canines in the symphyseal area, the prevailing force varies with type of occlusal loading, producing a torsion effect at the alveolus and inferior border (Fig. 37).290 The alveolus and inferior 52 SRPS • Volume 11 • Issue R8 • 2015 Figure 37. Natural forces acting on the mandible from the pull of the masseter, medial and lateral pterygoids, and temporalis muscles (tension) and the geniohyoid, genioglossus, mylohyoid, and digastric muscles (compression). (Reprinted with permission from Niederdellmann and Shetty.290) The overall shape of the mandible is also affected by the presence or absence of teeth. Without tooth eruption, the alveolar bone will not develop. The alveolar bone resorbs if teeth and their functional stimuli are lost. An edentulous mandible will atrophy at the alveolar ridge, with consequent decrease in vertical dimension of its tooth-bearing portion. Bone Healing Mandible healing is similar to that of long bones, depending largely on bone contact at the fracture site and the degree of movement. Primary healing is direct bone formation without multistage connective tissue and cartilage differentiation.291 Fibroblasts form along the long axis of the fractured bone, followed by osteoblasts, which produce new osteons. Direct union of touching fragments is accomplished via remodeling of haversian canals. Absolute stability, such as that achieved after placement of rigid bone plates and screws, is necessary for this type of contact healing to occur. Gap healing occurs in closely adapted and compressed fractures in which not all bone surfaces are in contact. Lamellar bone is deposited perpendicular to the long axis of the fractured bone and is subsequently remodeled, thus achieving final healing in two stages. Secondary healing, which occurs when there is relative instability of the reduced fracture and mobility of bone ends, such as with MMF with wires, has well-defined phases.292 Disruption of the Haversian systems results in bone death and resorption of the fracture ends. A callus consisting of clot, fibrous tissue, and osteogenic cells of periosteal and endosteal origins is formed to stabilize the fractured segments. Differentiation of osteogenic cells forms new trabecula or chondroblasts, which in turn form cartilage. Callus remodeling ultimately replaces cartilage with bone (Fig. 38). Despite the intermediate stages of tissue differentiation in secondary as compared with primary healing, the time to stable bone is equivalent. Classification Fractures are classified as closed or open, displaced or nondisplaced, complete or incomplete, and linear or comminuted.159 Angulation of the fracture line is of little clinical significance. A fracture is considered open if it communicates with the external environment through a tear in the mucosa or skin or with a tooth socket. Nondisplaced fractures often occur in the condyle, coronoid process, and ramus, partly because large muscle masses in those areas serve to stabilize the fractures. Displaced fractures can be the direct result of the trauma sustained or can occur secondary to muscle contraction and subsequent distraction of the fractured segments. Common sites of displaced fractures are the body, symphysis, and angle, probably because of the lack of support by major muscle groups in the direction of muscle pull in these regions. Epidemiology The thick, cortical, inferior border of the mandible renders it an efficient stress-absorbing structure. Its prominent position and its mobility predispose it to injury from trauma directed at the lower facial third. More than half of all mandibular fractures are caused by personal assault. Motor vehicle collision is the second most common cause. Fracture site is related to type of trauma. Personal assault, usually involving a laterally directed impact, will produce frequent body and angle fractures and fewer condylar, symphyseal, and alveolar fractures. Motor vehicle collisions, which involve posteriorly directed 53 SRPS • Volume 11 • Issue R8 • 2015 Figure 38. Types of bone healing. A, Primary bone healing by direct contact of the fractured ends. B, Primary healing in which lamellar bone bridges the gap between the segments. C, Secondary bone healing involving callus formation and remodeling. forces along the anterior mandible, produce fractures in the symphyseal, alveolar, and condylar regions.293 One series cites a 24.5% incidence of multiple fractures of the mandible. Otherwise, most fractures seem to occur in the body of the mandible.294-298 translation of the ipsilateral condyle, indicating a possible condylar fracture. The TMJ is assessed via palpation of the external auditory canal and preauricular area. A positive tongue blade test (patient able to grasp and hold tongue blade against attempt to remove it) excludes mandibular fracture.299 Physical Examination—Palpation elicits tenderness and can define fracture edges or cause movement of segments. Pain, malocclusion, trismus, swelling, anesthesia, paresthesia, hemorrhage, and ecchymosis are associated with fractures. If the injury is several days old, pain and swelling might be secondary to an inflammatory process and the ecchymosis might have migrated away from the fracture along fascial planes. Avulsed, loose, or fractured teeth found during intraoral examination should be documented. Multiple crowded, rotated, or missing teeth make fracture reduction more difficult. Malocclusion should be recorded and compared with the preinjury occlusion, recognizing that malocclusion often is present in the general population and is not necessarily the result of a fracture. Preinjury occlusion is ascertained by matching the wear facets on the cusps of the mandibular teeth with the opposing wear facets on the maxillary teeth. Ecchymosis in the floor of the mouth often indicates a fracture. Function is assessed by measuring incisional opening and lateral excursion. Mandibular protrusion and deviation during opening denotes limited Radiographic Evaluation—Three imaging techniques evaluate suspected mandibular fractures: mandibular series, Panorex, and CT scanning. A mandibular series Diagnosis 54 SRPS • Volume 11 • Issue R8 • 2015 consists of facial radiographs in the anterior, posterior, right and left lateral, oblique, and Towne projections. Condylar and subcondylar areas frequently are obscured by superimposed structures in the Towne view, but careful interpretation should disclose any fractures in the region. A properly performed and interpreted mandibular series yields 90% sensitivity. A Panorex image is the best diagnostic tool in cases of suspected mandibular fractures, allowing easy identification of condylar and ramus fractures and showing relation of the fracture line to the mandibular teeth. Properly performed and interpreted Panorex imaging has a sensitivity of 90% and is highly cost effective.300 Panorex plus anteroposterior view radiograph is perhaps the best combination of plain films. Although a CT scan cannot provide the details of dental occlusal relationships that a Panorex does, the sensitivity for all anatomic fractures is close to 100%.301,302 Cervical spine injuries must be ruled out in all patients with mandibular fractures. Based on an analysis of mandibular fractures and related cervical spine injury, Andrew et al.303 recommended using liberal guidelines for obtaining cervical spine films of any patient with cervical tenderness, neurological deficit, multisystem injury, or loss of consciousness. Management Goals 1)Achieve anatomic reduction and stabilization 2)Reestablish pretraumatic functional dental occlusion 3)Restore facial contour and symmetry 4)Balance facial height and projection Conservative treatment includes a soft or liquidonly diet for at least 30 days after trauma, restricting mouth opening, and maintaining oral hygiene.304 Patients must be followed closely to ensure that pretraumatic occlusion is preserved until the fracture is completely healed. Surgical Treatment Restoration of pretraumatic occlusion is paramount, regardless of the specific anatomic site of injury. The location and condition of fracture dictate the type of reduction and immobilization in each case. Closed reduction is used for either nondisplaced or minimally displaced fractures. Arch bars and wires are applied, and then maxillomandibular wires or elastics are added for 2 to 6 weeks to ensure stable reduction.297,305 Displaced fractures usually require open reduction with or without internal plate fixation. Timing of Reduction Reduction should be performed as soon as possible to minimize pain, prevent progression of soft-tissue injury, and reduce risk of infection. If treatment must be delayed, the fracture should be temporarily stabilized with bridle wires around the teeth adjacent to the fracture. Edentulous patients can be temporarily stabilized with external dressings such as a Barton bandage or cervical spine collar. Open fractures should be immobilized within 72 hours of injury.306 If definitive treatment is delayed longer than 3 days, infection at the fracture site should be treated with MMF and intravenously administered antibiotics before performing ORIF. Oral hygiene should be maintained in the interim until reduction. Nonsurgical Treatment Treatment by Fracture Site The following characteristics indicate conservative treatment: Many mandibular body fractures can be managed by closed techniques, particularly if the fracture is isolated and reducible and the teeth are intact. If multiple teeth are missing or if substantial displacement or comminution is present, ORIF is indicated. 1)Radiographic evidence of minimal or no displacement 2)Pretraumatic dental occlusion 3)Normal mandibular range of motion The fracture usually is approached through an intraoral incision. After reduction and IMF, a plate is 55 SRPS • Volume 11 • Issue R8 • 2015 applied along the inferior border. Although not usually necessary, an extraoral approach via Risdon incision (Fig. 39) also provides access to the fracture.307 Either an arch bar at the alveolar process or a second monocortical plate at the superior border is indicated as a tension band.308 Masseter muscle Skin incision Marginal mandibular branch of VII Periosteal incision Figure 39. Risdon incision. VII, cranial nerve VII. (Modified from Fonseca and Walker.307) Traditional treatment of severely comminuted mandibular fractures is by closed reduction to avert periosteal stripping. Smith and Johnson309 were successful using an extraoral approach with 2.0-mm miniplates for 16 comminuted fractures. All patients healed to bony union without grafting and with satisfactory postoperative form and function. Angle fractures often are the result of personal assault. A single lateral blow to the side of the face can produce a mandibular angle fracture, commonly associated with a fracture of the contralateral mandible.295 The angle is prone to fracture for several reasons, including the presence of third molars, which decrease osseous support; a thinner cross-sectional area; and biomechanical lever effect on the angle. Patients with third molars sustain a higher percentage of angle fractures.310 Management of third molars at the site of a mandibular angle fracture is controversial. Damaged or diseased teeth and those preventing reduction should be extracted. Otherwise, the molar should be maintained because it contributes to the strength and stability of the angle region. 56 Angle fractures are associated with the highest surgical complication rate, and their treatment has evolved substantially during the past 15 years.310 Most angle fractures are best managed with ORIF because of their tendency toward displacement of the proximal segment. The fracture can be exposed and plated via a buccal vestibule incision, which leaves no external scar and reduces the risk of marginal mandibular nerve injury. Angle fracture fixation methods have evolved from absolute rigid fixation using plates larger than 2.4 mm along the inferior border to the use of smaller double 2.0-mm non-compression plates to the application of a single, malleable, non-compression miniplate for bony fixation.310-315 Ellis310 presented a landmark 10-year study of mandibular angle fractures treated by closed reduction or intraoral ORIF with a rigid AO/ASIF reconstruction bone plate or by two 2.0-mm mini dynamic compression plates, two 2.4-mm dynamic compression plates, two non-compression miniplates, or a single non-compression miniplate. The large series had a high complication rate (17%) associated with closed reduction and nonrigid fixation. The use of either extraoral ORIF with the AO/ ASIF reconstruction plate or intraoral ORIF with a single miniplate was associated with the fewest complications. Ellis contended that angle fracture complications are inversely proportional to the rigidity of the fixation applied. He noted the following: 1)Higher complication rates are associated with two points of fixation versus singlepoint fixation. 2)Single miniplate fixation requires more limited dissection than absolutely rigid, two-plate fixation. 3)Absolute rigidity might not be required for mandibular angle fracture healing. 4)Complications arising from single miniplate fixation are more easily managed and often do not require readmission or reoperation. The use of a solitary lag screw has been described for the treatment of mandibular angle fractures.316 Although lag screws provide highly satisfactory fracture reduction and a low complication rate, the results are sensitive to the operative technique used. Comminuted angle fractures are SRPS • Volume 11 • Issue R8 • 2015 rare, but when multiple fragments are present, an external Risdon incision improves access to the fracture for better control of fragment reduction and stabilization. Stable symphyseal fractures in patients with normal occlusion can be treated by closed means. True midline fractures are rare; parasymphyseal fractures are common. ORIF is appropriate for many of these fractures via intraoral incision. Reduction forceps are used to anatomically align the bone fragments, and the jaws are placed in pretraumatic occlusion while plates or lag screws are applied to immobilize the fracture.316 Lag screws are elegant, minimally invasive, and well suited for reduction of symphyseal and parasymphyseal fractures. Biodegradable polylactide screws have also been used with good success.317 Stabilization typically requires two 2.0-mm miniplates, a single 2.4-mm or 2.7-mm plate, or an inferior border miniplate and an arch bar. Care must be taken to avoid stretching or avulsing the mental nerves exiting the mental foramen. Ramus fractures seldom are displaced, probably because of the splinting effect of the masseter, temporalis, and medial pterygoid muscles. Vertical and horizontal fractures of the ramus usually are treated by closed reduction and MMF. Similarly, fractures of the coronoid process seldom require ORIF and are managed conservatively. Condyle fractures are grouped into head, neck, and subcondylar regions. The neck is prone to fracture because of its relatively small diameter. During blunt impact to the mandible, kinetic energy is transferred along the length of the jaw to the condylar neck, where the force of the blow frequently exceeds the compressive strength of the bone.318-320 In contrast, a condylar head fracture is an intracapsular injury and has a proclivity for ankylosis. If no malocclusion has been generated by the fracture, these injuries can be treated without MMF and the patient can be placed on a soft diet. If malocclusion is present, the patient should be placed in MMF with either rigid fixation or elastics for 2 weeks, at which time a regimen of intraoral elastics is started. A postfixation physiotherapy program is essential. Stretching exercises consisting of active incisor opening and lateral excursions eventually progress to active and digitally assisted jaw levering. Open versus closed reduction of subcondylar and condylar neck fractures remains a contentious point. Previous work321,322 supports a conservative approach (closed reduction) of these fractures. In 1947, a report from the Chalmers J. Lyons Club presented data on 120 cases of condylar fractures that favored closed reduction.321 A more recent study from Austria322 compared 229 consecutive patients with subcondylar and condylar neck fractures, 161 of which were treated with MMF. The other 68 were treated with ORIF. The results showed no significant differences in mobility, joint problems, or occlusion. Another landmark study293 examined 348 patients with condylar fracture for distribution patterns and fracture causes. The results of conservative treatment were reported, revealing similar occlusal and functional results in patients treated with ORIF, supporting conservative, nonoperative treatment of condylar fractures. Joos and Kleinheinz323 list the following indications for nonsurgical treatment of condylar fractures: 1)Condylar neck fractures in children 2)High condylar neck fractures without dislocation 3)Intracapsular condylar fractures Proponents of ORIF are critical of the conservative approach, believing that TMJ dysfunction has been underreported and that a higher incidence of traumatic arthritis, decreased range of motion, and malocclusion might exist than previously suspected in closed reduction series.323-325 Zide and Kent320 described four absolute indications for open reduction of condylar neck fractures: 1)Displacement of the condyle into the middle cranial fossa 2)Difficulty obtaining adequate occlusion by closed reduction 3)Lateral extracapsular displacement of the condyle 4)Foreign body within the condyle 57 SRPS • Volume 11 • Issue R8 • 2015 Treatment method is determined by the degree of fracture displacement and condylar dislocation. Klotch and Lundy326 provided a particularly useful algorithm (Fig. 40). Ellis and colleagues170,327−332 reported a 10year, 200-patient experience with condylar fractures and concluded the following: 1)More consistent occlusal results can be expected in fractures of the mandibular condylar process treated by open reduction. 2)Greater postoperative condylar mobility is expected in patients treated by open reduction. 3)More consistent facial symmetry is achieved with open reduction techniques. Bilateral subcondylar fractures associated with midfacial fractures traditionally are managed with ORIF of the condylar neck, at least unilaterally, to reestablish the vertical facial dimension. Newman333 presented an analysis of long-term outcomes of bilateral condylar fractures that supports ORIF. However, proceedings of the Netherlands meeting in 1988 found little scientific evidence that a period of rigid IMF has any benefit, that it might adversely affect future joint function, and that closed treatment normally consists of a delay while swelling and spasm settle. Non-rigid MMF with elastics is then applied for 1 to 6 weeks.325 Proponents of endoscopic fixation of condylar fractures334-337 asserted that the technique offers the benefits of direct fracture reduction with better visualization and precise anatomic alignment of the bony segments without the facial scars and nerve injuries associated with open techniques. Endoscopic techniques have been expanded to the management of late complications. Troulis et al.171 described a series of 10 consecutive patients treated by endoscopic condylectomy and costochondral graft reconstruction followed for a mean of 17 months. Indications included idiopathic condylar resorption (seven cases), malunion of a fractured condyle (two cases), and degenerative joint disease (one case). No complications occurred, and good correction of occlusion and mandibular position were reported. Transient facial nerve weakness is the most common complication of open treatment of condylar process 58 fractures.332 Hypertrophic scarring, which in the series presented by Ellis338 averaged 7.5%, ranks second. The clinical and surgical factors predisposing to malocclusion, hypomobility, facial asymmetry, and dysfunction have also been examined.338 Facial morphology after open (n = 65) versus closed (n = 81) treatment for condylar fractures revealed increased facial shortening with closed techniques.338 Fixation Devices External Appliances—External skeletal fixation (with the Joseph Hall Morris biphasic appliance) was previously widely practiced.305,339-345 Although largely replaced by internal fixation techniques, external fixation is still useful in stabilizing large, comminuted defects from gunshot wounds or severe mandibular infections with osteomyelitis. Splints—The indication for splinting is lack of adequate dentition on which to place arch bars for MMF, such as in children who are at mixed dentition stage or in adults who are missing teeth. Maxillomandibular Fixation—Problems associated with the use of MMF include feeding difficulties and subsequent nutritional insufficiency, airway compromise, social and communication difficulties, and poor oral hygiene. In an otherwise healthy patient, these are not serious consequences, but in the elderly and otherwise compromised patients, MMF can be problematic.346 The duration of fixation clearly is dependent on the specifics of the fracture. Chuong et al.347 achieved clinical union by 4 weeks in 79% of fractures and by 5 weeks in 90%, based on weekly palpation and manipulation of the fracture site. In most cases, release of fixation is possible by the third or fourth week.347 Rigid Internal Fixation—Since the early 1970s, rigid internal fixation has undergone many modifications.348,349 Current trends are toward the use of rigid internal fixation techniques and smaller hardware to achieve fixation, and the period of MMF is minimized. SRPS • Volume 11 • Issue R8 • 2015 Dentulous Bilateral Unilateral Not dislocated or telescoped Dislocated or telescoped IMF Generally ORIF Not dislocated or telescoped Dislocated or telescoped No midface Unstable midface No midface Unstable midface IMF Possible ORIF ORIF at least one side ORIF both sides Figure 40. Algorithm for treatment of condylar neck fractures in the adult dentulous mandible. (Modified from Klotch and Lundy.326) An understanding of the biomechanical principles of jaw function and the forces acting on the mandible is paramount to the success of internal fixation techniques. Masticatory movements of the jaw result in tension along the alveolus in the body and angle and compression along the inferior border in the same areas. Fixation plates must be applied so as to counteract these deforming forces. AO/ASIF versus Champy—AO/ASIF espouses rigid fixation. Champy philosophy advocates less rigid but functionally stable fixation. Champy proposes strategic placement of plates along natural lines of force to sufficiently stabilize fractures and achieve union and avoids the inherent disadvantages in using larger plates (i.e., difficulty in plate contouring, wide exposure, malocclusion).350-352 Szabó et al.353 described the technique of internal fixation of mandibular fractures using these principles, the best example of which is the use of a single miniplate along the oblique ridge of the mandible to stabilize an angle fracture.354-356 Outcome studies comparing the two philosophies showed similar results. Davies et al.356 treated 64 consecutive displaced fractures using Champy principles without postoperative IMF and showed favorable results with an overall complication rate of 3% and no postoperative malocclusion. Chuong and Donoff,357 Dierks,358 Souyris et al.,359 and Nishioka and Van Sickels308 detailed transoral fracture plating schema. Regardless of technique, the main advantage of plates and screws to treat mandibular fractures is the elimination of IMF. In the majority of plated fractures, postoperative IMF is unnecessary unless 59 SRPS • Volume 11 • Issue R8 • 2015 concomitant fractures (subcondylar) dictate the need for jaw immobilization. Compared with MMF, plating dramatically shortens the time to normal jaw function and helps maintain body weight.360-362 Lag Screws—Ellis and Ghali316,363 reviewed lag screw fixation, confirming that a properly placed lag screw of the right length and design creates sufficient bony compression and stability to successfully repair oblique fractures of the body, symphysis, and angle (Fig. 41).364 Shetty and Caputo365 evaluated the biomechanics of a solitary lag screw technique in the management of mandibular angle fractures, finding that the solitary screw, as a tension band, provides sufficient compression and stability to withstand functional mandibular loading. Niederdellmann and colleagues290,366 popularized the use of a 20- to 40-mm lag screw in the angle, reducing the fracture via an intraoral incision and single transbuccal lag screw. Leonard367 reviewed the many uses of lag screws in mandibular fractures. Locking Reconstruction Plates—Originally developed for postresection mandibular reconstruction, locking plates are available in a wide range of sizes and provide rigid fixation with low-profile, high-strength plates that do not require absolutely precise plate contouring.368-373 Advantages include the following: 1)Easier adaptation to bone contour 2)Less plate hole deformation 3)Less plate palpability 4)Stable fixation, even in poor-quality bone 5)Less risk of screw loosening or stripping 6)Less sensitive to operative technique Herford and Ellis368 analyzed the results of mandibular reconstruction with a locking bone plate and screw system in 84 patients. The authors found loss of fixation in one case and no cases of malocclusion or technical difficulties. Stability without requiring the plate to be compressed to the bone was cited as a major advantage over conventional plating techniques. Kirkpatrick et al.370 noted a 6.4% infection rate, although no loss of fixation occurred in their series. 60 Figure 41. Lag screw is inserted through a drill hole of the same diameter as the screw threads. In the inner cortex of the bone, the drill bore should match the inside diameter of the screw. (Modified from Spiessl.364) Children Mandibular fractures represent 5% to 50% of pediatric facial fractures, with the most common cause being motor vehicle collision.372 During early childhood, the mandible is weakened by numerous unerupted and developing permanent teeth, which limit the amount of bone and create regions susceptible to fracture (Fig. 42).373 Nevertheless, fractures in children tend to be incomplete and minimally displaced because of the relative lack of thick cortical bone and tissue elasticity, which allows the bones to bend rather than break.374 Two-thirds of mandibular fractures in children younger than 10 years occur in the condylar region.375-379 The proportion drops to approximately 40% in children who are 11 to 15 years of age. The treatment of mandibular fractures in children is different from that in adults because of the presence of deciduous and unerupted teeth.380 Other factors influencing management options are the capability for rapid healing in children and the risk of treatment interfering with future mandibular growth. Most fractures are best managed by closed reduction. ORIF often is difficult because the developing tooth buds leave little room for placement of fixation devices.380-382 SRPS • Volume 11 • Issue R8 • 2015 establish preinjury occlusion. An acrylic splint is fashioned to the lingual surface of mandibular dentition and is secured with circummandibular wires. Permanent canine Premolars First permanent molar Permanent incisors Second permanent molar Second permanent molar Premolars First permanent molar Permanent incisors Permanent canine Figure 42. Location of developing permanent tooth buds in the pediatric maxillofacial skeleton must be kept in mind when applying rigid plate fixation. (Modified from Winzenburg and Imola.373) Regarding closed reduction, stabilization is most frequently achieved with either IMF or lingual splints. The use of arch bars in children younger than 9 years frequently is problematic. It is difficult to maintain wires around the bases of the deciduous teeth because of the absence of a distinct cingulum and because these teeth are prone to extrusion when the wires are tightened. IMF is best achieved using a circummandibular wire anteriorly connected to a wire passed through a drill hole in the piriform aperture. Stabilization of parasymphyseal and body fractures can also be achieved using lingual splints fashioned from dental impressions. In the case of displaced fractures, the models are cut at the fracture site and are repositioned to Condylar head fractures in children are associated with risk for growth disturbance.42,381-387 The condyle in children is highly vascular and can fragment when subjected to compressive trauma, with resultant hemarthrosis and subsequent ankylosis. Early mobilization to prevent ankylosis and close follow-up to detect growth disturbances are imperative. In condylar neck or subcondylar fractures, preservation of ramus height and TMJ function are key. Closed reduction usually is sufficient, with lingual splints to bridge other associated fractures. Immobilization is limited to 5 to 10 days, and active exercises then begin.372-377 Multiple long-term outcome studies support conservative management of pediatric condylar fractures.42,361,388−392 Nørholt et al.42 found that the functional and aesthetic results 10 years after condylar fractures were satisfactory after conservative treatment in 55 patients whose ages were 5 to 20 years. For patients older than 18 years, however, operative treatment proved superior. Posnick et al.393 noted that 34% of 318 pediatric facial fractures involved the mandible. Based on that series, the authors advocated conservative treatment of most condylar process injuries and nondisplaced, simple body and angle fractures. Comminuted or displaced fractures are treated by ORIF. Rémi et al.394 retrospectively reviewed 30 fractures in 19 pediatric patients with a mean follow-up duration of 28 months. The condyle was involved in 16% and the subcondylar region in 28% of cases. Conservative functional (closed) treatment was used in the majority of cases. Body and condyle fracture combinations were treated by ORIF and MMF. No infections or facial growth disturbances were reported. One patient had TMJ pain syndrome. Conservative treatment of condylar fractures in children, when followed by early restoration of function and diligent physiotherapy, can be expected to produce good healing, normal growth of the jaw, and little or no interference with movement of the TMJ. 61 SRPS • Volume 11 • Issue R8 • 2015 Edentulous Patients Fractures in edentulous patients are difficult to treat because: 1)Teeth on which to anchor maxillomandibular fixation are lacking. 2)The alveolar ridge often is atrophic and the mandibular cross-section is small, so that muscle pull easily displaces the fragments. 3)The fractured bone is primarily cortical, with little capacity for repair. Fixation with skeletal wires attached to dentures frequently is inadequate and unstable without risking soft-tissue necrosis. Closed management involves the use of existing dentures or Gunning splints to stabilize the fracture or the use of external fixators such as the Morris appliance. Closed treatment avoids periosteal stripping of already atrophic bone. However, a series presented by Bruce and Ellis395 of 104 consecutive edentulous fractures found higher rates of delayed or fibrous union in closed treatment versus ORIF (25% versus 12.6%) and increased morbidity, increased disability time, worse jaw function, and worse aesthetics. Plates should be large (>2.4 mm), and screws should be locking screws. The authors correlated treatment results with degree of atrophy and recommended supraperiosteal plating along with primary bone graft when alveolar height is significantly reduced. Teeth in the Line of Fracture With increasing understanding of jaw function biomechanics, teeth are retained whenever possible and removed only when nonrestorable or severely broken.399-402 Even then, they sometimes are retained for stabilization and carefully extracted only after MMF release. Shetty and Freymiller403 offered guidelines for the management of teeth in the line of fracture: 1)Intact teeth in the fracture line should be left in situ if they show no evidence of severe loosening or inflammatory change. 2)Impacted molars, especially complete bony impactions, should be left in place to provide a larger repositioning surface and for the application of tension bands. The exceptions are partially-erupted molars with pericoronitis or associated with a follicular cyst. 1)Edentulous patients tend to be older and have systemic disease. 3)Teeth that prevent reduction of fractures are removed. 2)Associated anesthetic risks and postoperative morbidity are high. 4)Teeth with exposed root apices or where the fracture line follows the root surface from apical region to gingival margin tend to develop healing complications. Hemisection should be considered as an alternative to extraction. Bone plate placement is controversial. Bradley396,397 demonstrated that the main blood supply to the edentulous mandible is via a subperiosteal plexus dependent on overlying soft tissues and therefore recommended supraperiosteal plating. However, treatment failures are recognized as secondary to fragment instability rather than inadequate blood supply.312 Luhr et al.398 presented a report of 84 edentulous fractures treated with compression plates without postoperative MMF, proposing a classification system for mandibular atrophy that is based on midpoint body vertical bone height, as follows: 5)Teeth with crown fractures may be retained, provided emergency endodontic therapy. All teeth with fractured roots must be removed. 6)Teeth that appear nonvital should be treated conservatively, recognizing recovery potential. 7)Primary extraction is preferred when extensive periodontal damage with broken alveolar walls and a deep pocket. •• Class I, 16−20 mm •• Class II, 11−15 mm •• Class III, <10 mm 62 A 117-patient study conducted by Baykul et al.404 SRPS • Volume 11 • Issue R8 • 2015 further supports the practice of retaining asymptomatic impacted teeth in the uncomplicated fracture line. Open fractures were treated with IMF, and no unerupted teeth were extracted. No complications occurred, and fractures healed without sequela. Tooth fractures range in severity from cracks in the enamel to complete breaks in the crown. A partial fracture of the crown in a tooth that is otherwise intact with a stable root is an indication for restorative dentistry.290,405-407 Postoperative Care The airway is the primary concern in patients treated with MMF. A nasogastric tube, positioned during surgery, should be left in place until the patient is ready for extubation. A patient with MMF applied should not be extubated until fully awake. Prophylactic antibiotics are recommended for all open facial wounds, such as compound mandibular fractures. Zallen and Curry408 reported a 50% infection rate without antibiotics. No correlation exists between infection and the removal or retention of teeth. Feeding should progress from clear liquids, to a high-protein full-liquid diet, to a blended diet.409 Complications Potential complications include infection, malocclusion, malunion, nonunion, plate exposure, and nerve injury. Nonunion frequently is the result of inadequate fracture immobilization or alignment, interposition of tissue or foreign body between fracture fragments, infection, segmental bone loss, and plate misapplication.410 A series of 308 patients presented by Moulton-Barret et al.411 revealed a 14% overall complication rate, with infection accounting for half of the complications and malunion and malocclusion the remainder. The incidence of nonunion is 3.2%, with the mandibular body comprising most of these. Haug and Schwimmer412 identified risk factors predictive of nonunion, finding that inadequate immobilization, location (mandibular body), teeth in the line of fracture, and late postsurgical infections correlated well with the development of fibrous union. Alcohol and drug abusers and noncompliant patients are also at high risk for nonunion. Conversely, age, race, sex, mechanism of injury, and failure to use antibiotics were not risk factors. Treatment of nonunion includes removal of infected teeth, débridement the fracture, and reapplication of rigid internal fixation with or without bone grafting.412 Mathog et al.413 analyzed a 906-patient series (1432 fractures) to identify factors contributing to nonunion and found that multiple fractures were associated with nonunion, the mandibular body was often involved, and osteomyelitis was a frequent finding. Failure to provide antibiotics, treatment delay, teeth in the fracture line, alcohol and drug abuse, surgeon inexperience, and patient noncompliance also correlated with complications. Pretreatment inferior alveolar nerve sensory abnormalities are found in 56% of patients with fractures between the mandibular and mental foramina and become permanent in 19%.414-416 Malocclusion is entirely preventable. The most common cause of malocclusion is maladaption of the plate used for fixation, with resultant bony malreduction and movement of dentition. This should be recognized at the end of surgery when MMF is released and occlusion assessed. Any occlusal discrepancy should prompt the surgeon to remove fixation, reestablish MMF, and reapply bone plates. Considering that postoperative malocclusion secondary to internal fixation requires repeat operation in the vast majority of cases, the surgeon should not rely on elastics or MMF to correct the problem. 63 SRPS • Volume 11 • Issue R8 • 2015 REFERENCES 1. Prein J, Rahn BA. Scientific and technical background. 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