Download Laser in Contemporary Maxillofacial Surgery

Laser in Contemporary Maxillofacial Surgery
BY
RO B E R T A . S T R A U S S, D D S, M D
S T E V E N D. FA L L O N, D M D
PRESENTED BY
H A N I S. A L - M O H A R I B
DENT CLIN N AM 48 (2004) 861–888
Outline
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Introduction.
Types and Wavelenghts.
Principles of Laser Physics.
Advantages and disadvantages.
Techniques for use in OMS.
Introduction
 Lasers are becoming the standard of care for many oral and maxillofacial
procedures.
 They are being introduced as an efficient instrument for a variety of new
applications.
Introduction
 Oral and maxillofacial surgery (OMS) has included the use of lasers since the
mid-1960s.
 Lasers are becoming increasingly popular due to the advent of office-based
lasers, which are:
1. Small.
2. Portable.
3. Easy to manipulate within the oral cavity.
Types and Wavelenghts
 There are many different laser wavelengths that have been used in OMS, Such
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as:
CO2 laser.
Nd:YAG laser.
Er:YAG laser.
Ho:YAG laser.
Argon laser.
Semiconductor diode lasers.
Nd: Neodymium, Y: Yttrium, A: Aluminum, G: Garnet, Er: Erbium, Ho: Holmium
CO2 Laser (10,600 nm)
 CO2 laser is one of the most widely employed lasers in OMS.
 CO2 laser is ideal for most soft tissue surgeries because it has excellent
affinity for water-based soft tissues.
 The absorbed energy causes:
1. Vaporization of the intracellular and extracellular fluid.
2. Blood vessels of approximately 500µ or less are sealed spontaneously.
Nd:YAG Laser (1064 nm)
 The Nd:YAG laser’s active medium is a crystal of yttrium, aluminum, and
garnet doped with neodymium ions.
 Nd:YAG laser exhibits:
Minimal surface tissue absorption.
2. Maximal penetration
This allows for coagulation of tissue in depth so that vessels 2 to 3mm in
diameter can be ablated.
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Nd:YAG
 Because the pulse duration is shorter than the time required to initiate a nerve
action potential, Romanos et al., believed that most procedures could be
performed without local anesthesia and minimal bleeding.
 The Nd:YAG laser also is unique in that it can be used in a contact (excision)
and a noncontact (coagulation) mode.
Nd:YAG
 These properties have led to its use in a variety of maxillofacial procedures,
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including :
Coagulation of angiomatous lesions.
Hemostasis in bleeding disorders.
Arthroscopic surgery of the TMJ.
Resections in vascular tissues.
Palliation of advanced neoplasms.
Er:YAG (2940 nm)
 Er:YAG laser is particularly attractive for use in dental implant surgery.
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Because:
Beam is reflected by polished metal surfaces.
No adverse effects on titanium surfaces.
Application of the Er:YAG laser in dental implant surgery has been advocated
for:
Preparation of hard tissue.
Second-stage surgery.
Revision of soft tissue.
Treatment of peri-implantitis.
Ho:YAG (2100 nm)
 The Ho:YAG laser offers:
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Minimal lateral heat transfer and less peripheral tissue damage.
Profound hemostasis.
Precise cutting and controlled depth of penetration compared with surgical
shavers and scalpels.
Can be used easily through saline solution or lactated Ringer’s solution.
All of these characteristics make the Ho:YAG laser the perfect instrument for TMJ
arthroscopic procedures, such as diskoplasty, diskectomy, and synovectomy.
Argon Laser (514 nm)
 Argon laser is indicated for treatment of dermatologic, labial, and oral lesions
with a large vascular component.
 Argon laser is absorbed by pigment-containing tissues, including hemoglobin
in erythrocytes, melanin in melanocytes, and other dark pigments.
Semiconductor Diode Lasers (805-980 nm)
 The optical penetration is less than that of the Nd:YAG laser; this is potentially
beneficial for the treatment of superficial and interstitial lesions.
 Romanos and Nentwig et al., found that the incision margin using the diode
laser is more precise compared with other systems, including the CO2 and
Nd:YAG lasers.
Principles of Laser Physics
 Lasers are totally absorbed by water within the first 0.1 mm of the tissue
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surface, causing, at 100C:
Intracellular water to vaporize and expand.
Leading to cellular rupture.
Loss of 75% to 95% of the cell volume as steam.
At higher temperatures, the residual organic matrix also vaporizes, resulting
in total tissue ablation.
Principles of Laser Physics
 Given enough time, heat begins to leak laterally by thermal conduction.
 This leads to useful hemostasis, 500 µm of thermal damage in skin uniformly
results in scarring.
 Control of lateral thermal damage is paramount to the use of lasers in OMS.
Principles of Laser Physics
 Three parameters controllable by the surgeon function to control the laser’s
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effect on tissues:
Power.
Time on target.
Effective spot size of the beam.
By adjusting these parameters, one can create a deep thin cut into tissue for
incision or excision or a wide superficial surface vaporization for tissue
ablation.
Advantages
A.
The hemostatic nature of the laser allows surgery to be performed more
precisely and accurately because of increased visibility of the surgical site.
B.
Decreased swelling allows for increased safety when performing surgery
within the airway.
Advantages
Tissue healing and scarring also are improved with the use of the laser due
to a combination of:
1- Decreased lateral tissue damage.
2- Less traumatic surgery.
3- Precise control of the depth of tissue damage.
4- Fewer myofibroblasts in laser wounds compared with scalpel wounds.
D. Decreased postoperative pain often can be obtained with the use of lasers
for surgery.
C.
Disadvantages
A.
B.
Lasers does not yet compare favorably with conventional techniques for
osseous surgery (eg, extraction of impacted teeth and osteotomies).
Speed of healing usually is prolonged compared with other types of wounds
due to:
1- Sealing of blood vessels and lymphatics.
2- The need for neovascularization for healing.
- Typical intraoral healing takes 2 to 3 weeks for wounds that normally
would take 7 to 10 days.
Techniques for use in OMS
 There are basically three photothermal techniques for laser use on soft tissues
within the oral cavity and on the face:
1. Incisional procedures.
2. Vaporization procedures.
3. Hemostasis.
Incisional and excisional procedures using the CO2 laser
 This technique allows the surgeon to perform almost any intraoral procedure
that normally would be done with a scalpel, such as incisional or excisional
biopsy, lesion removal, or incision for flap access.
 this technique would require a fairly high-power density using a small spot
size to create a deep but thin cut, as would be needed to make an incision.
Incisional and excisional procedures using the CO2 laser
 Typical lesions treated by excision and incision include the following:
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Fibroma.
2.
Mucocele.
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Papilloma.
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Gingival lesions.
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Benign salivary gland lesions.
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Salivary stones.
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Malignancy removal.
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Incisional biopsy.
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Excisional biopsy.
10. Vestibuloplasty.
11. Epulis fissurata.
12. Hyperplastic tissue excision.
13. Implant uncovering.
14. Peri-implantitis.
15. Tongue lesions.
basic technique for laser excision demonstrated in the removal of a mucocele.
(A) Outlining specimen in a repeating pulse fashion.
(B) Connecting outlined dots to create a vertical cut around lesion.
(C) Undermining and removing the specimen.
Excision of T1N0M0 carcinoma of lateral tongue. (A) Outline of lesion. (B) Undermining and excision of lesion. (C)
Resultant defect with large margins left unsutured. (D) Two-year postoperative view displays excellent healing with
minimal scarring and functional deficit.
Excision of tissue for second-stage implant surgery.
(A) Note lateral angulation of laser for exposure to avoid direct contact with implant fixture. An attempt should be made
to minimize removal of attached tissue.
(B) Exposure of implant.
Ablation and vaporization procedures
 Tissue ablation (also called vaporization) is used when the surgeon wishes to
remove only the surface of the target or to perform a superficial removal of
tissue.
 In these situations, the lesion usually is confined to the epithelium or to the
epithelium and underlying superficial submucosa.
 The laser is defocused by pulling the laser back from the target and allowing
the beam to widen to a spot size of 1.5 to 3 mm.
Ablation and vaporization procedures
 Typical lesions treated by vaporization include the following:
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Leukoplakias.
Dysplasia.
Lichen planus.
Papillary hyperplasia.
Hyperkeratosis.
Oral melanosis.
Papillomatosis.
Tissue hyperplasia.
Laser ablation of leukoplakia of buccal mucosa. (A) Diffuse leukoplakia of buccal mucosa. (B) Outline of lesion.
(C) Ablation completed and char layer removed. (D) Resultant tissue defect left unsutured.
Ablation and vaporization procedures
 Many clinicians believe that the hemostatic effect of the laser results in
decreased tendency for hematogenous or lymphatic seeding of the malignant
cells.
Premalignant lesion of mandibular gingiva. (A) Preoperative photograph shows extensive growth, making excisional
procedure difficult. (B) Defocused ablation of gingival lesion with remaining char layer.
Cosmetic Laser Surgery
 A common procedure performed is cosmetic skin resurfacing.
 This procedure treats facial lesions and skin wrinkles by:
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Removing the surface layer of the epidermis and superficial papillary dermis.
Contracting the dermal collagen.
Allowing the skin to reepithelialize in a more uniform manner.
Ablation of pigmented facial nevus. (A) Pigmented facial nevus on left brow. (B) Resultant char layer after ablation of
pigmented lesion. (C) Removal of char layer shows lack of remaining pigment.
Laser-assisted uvulopalatoplasty
 LAUP
has become an attractive alternative to traditional scalpel
uvulopalatopharyngoplasty (UPPP) for treatment of snoring and mild sleepdisordered breathing.
 The procedure is designed to enlarge the posterior airspace and reduce or
eliminate pharyngeal obstruction during sleep.
Dental implants
 Applications of the laser for implant surgery have focused primarily on:
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Soft tissue revision.
Second-stage surgery.
Decontamination of implant surfaces.
Treatment of peri-implantitis.
Dental implants
 Properties of the laser offer significant advantages for soft tissue management
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surrounding dental implants, including:
Improved control of possible hemorrhage.
Less mechanical trauma to the soft and hard tissues.
Prevention of local infection.
Less postoperative inflammation and pain.
Improved healing.
Decreased risk of postoperative bacteremia.
Dental implants
 Concerns have been raised regarding the hazards of laser applications around implants.
When using the laser, some of the energy may be absorbed or transferred to the
implant, causing deleterious effects.
Dental implants
 Kreisler et al., assessed the effects on different implant surfaces of Nd:YAG, Ho:YAG,
Er:YAG, and CO2 lasers and concluded that the first two types should not be used for
implant surgery because they harm the surface of all endosseous implants. The CO2 and
Er:YAG lasers can be used only at low power because they can affect the implant surface.
Dental implants
 Thermal damage also has been implicated in implant failures with adjunctive laser
surgery.
 Temperature increases of 47ºC to 50ºC have been shown to induce tissue damage in the
bone leading to necrosis and failed osseointegration.
Dental implants
 In second-stage implant surgery, bone often is found above the healing cap or at the
implant margins. Traditionally, this tissue has been removed using a combination of
rotary or manual instruments.
 In either case, extreme caution must be used to prevent damage to the implant surface.
This situation has led to the advent of lasers for implant uncoverings.
Dental implants
 Peri-implant infection results in inflammation of the surrounding soft tissues and can
induce a breakdown of the implant-supporting bone.
 The CO2, Er:YAG, and diode lasers have been shown to be safe and effective for treating
peri-implantitis.
Temporomandibular joint surgery
 Arthroscopic surgery has become the primary treatment of choice for surgical internal
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derangements of the TMJ. Lasers have several advantages compared with conventional
cutting instrumentation and techniques, such as:
Diseased tissues can be removed without mechanical contact.
Decreased trauma to the articular cartilage and synovial surfaces.
Hemostasis within the joint without causing thermal damage.
Technical precision of laser surgery is far superior.
Eliminates the possibility of instrument breakage and retrieval.
Temporomandibular joint surgery
 Using this technique, such procedures as:
Diskectomy.
2. Diskoplasty.
3. Synovectomy.
4. Hemostasis.
5. Posterior attachment contraction.
6. Eminectomy.
7. Debridement of fibrous ankylosis
- All these can be performed on an outpatient basis through two incisions less than 2 mm
each.
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Temporomandibular joint arthroscopy using a holmium:YAG laser. Separate ports are required to provide the surgeon
with visibility of the laser tip during use.
Summary
 The incorporation of lasers OMS has led to exciting advances in surgical therapy and
improved patient care.
 Advances in laser technology undoubtedly will yield new procedures and have a major
role in the future of minimally invasive surgery.
Thank You