Download Maxillary Reconstruction

Maxillary Reconstruction
 Maxillectomy defects become more complex when critical structures such as the
orbit, globe, and cranial base are resected
Anatomy
 The maxilla can be described as a geometric structure with six walls
(hexahedrium)
 The roof of the maxilla supports the ocular globe. The medial wall is the lateral
wall of the nasal cavity and is part of the lacrimal system
 The floor of the maxilla forms the anterior portion of the hard palate and the
alveolar ridge
 Several walls of the maxilla contribute to formation of the paranasal sinuses, and
the maxillary antrum is contained within the central portion of the maxilla.
 two horizontal and three vertical buttresses of the maxilla are responsible for
midfacial projection and vertical facial height.
 most muscles involved with facial expression and mastication are inserted on the
maxilla. These muscles, together with the overlying skin and/or intraoral mucosa,
constitute the lower eyelid, cheek, upper lip, and oral commissure.
 maxillary bone is usually included when resecting tumors that arise from the
paranasal sinuses, palate, nasal cavity, orbital contents, overlying skin, or intraoral
mucosa.
Classification (Cordiero PRS June 2000)
1. Type I defects (limited maxillectomy)
 resection of one or two walls of the maxilla, excluding the palate
2. Type II defects (subtotal maxillectomy)
 resection of the maxillary arch, palate, anterior and lateral walls (lower five
walls), with preservation of the orbital floor
3. Type III defects (total maxillectomy)
 resection of all six walls of the maxilla
 type IIIa, - the orbital contents are preserved
 type IIIb,- the orbital contents are exenterated
4. type IV defects (orbitomaxillectomy)
 resection of the orbital contents and the upper five walls of the maxilla, with
preservation of the palate
Reconstruction
 Free-tissue transfer provides the most effective and reliable form of immediate
reconstruction for complex maxillectomy defects.
 The rectus abdominis and radial forearm flaps in combination with immediate bone
grafting or as osteocutaneous flaps reliably provide the best aesthetic and
functional results.
 Bone replacement is essential in the floor of the orbit to maintain position of the
ocular globe- otherwise, the orbital contents sink into the cheek, creating a
dystopia, diplopia, and essentially nonfunctional eye.
 It is also useful in the maxillary arch to provide anterior projection of the midface
and bone stock for osseointegrated implants
 Bone grafts can be effectively used in conjunction with soft-tissue flaps (free or
pedicled) for reconstruction of the orbital floor, because this area requires minimal
supportive strength.
 Vascularized bone is indicated in the maxillary arch if osseointegration is required.
 Free flaps generally are indicated when skin islands are necessary for intraoral
cheek, palatal, nasal lining, or external resurfacing.
 The space between the restored anterior, superior, and inferior walls of the maxilla
can usually be filled with soft tissue (muscle/fat)
 nasal lining may or may not be necessarily restored.
 The temporalis flap covers bone effectively in these types of reconstruction but
does not close the palate; this requires subsequent use of an obturator. It is
therefore indicated primarily in older patients who are not candidates for freetissue transfer
 A superficial tunnel in the face-lift plane allows transfer of vessels; or, if the
maxillary tubercle is resected, access can be gained by a parapharyngeal approach
medial to the mandible
(Above) Type I (limited maxillectomy) defect. Note resection of anterior and medial
walls of maxilla (left). Resected specimen demonstrates skin/soft-tissue resection in
combination with bony resection (center, left). This creates a large surface-area/low
volume defect. The radial forearm fasciocutaneous flap (donor site depicted in inset)
provides multiple large skin surface areas with minimal volume (center, right).
(Right) Radial forearm fasciocutaneous flap is shown in place, demonstrating skin
islands to resurface anterior cheek and medial nasal lining. (Below) Type II (subtotal
maxillectomy) defect. Note resection of lower five walls of maxilla, including the
palate, but sparing the orbital floor (roof of maxilla) (left). Resected specimen
demonstrates palatal/nasal floor lining and bony resection. This creates a large
surface-area/medium volume defect (center, left). The radial forearm osteocutaneous
sandwich flap (donor site depicted in inset) provides large skin surface area with
vascularized bone and moderate volume (center, right). (Right) Radial forearm
osteocutaneous flap is shown in place, demonstrating strut of vascularized bone to
reconstruct the anterior maxillary arch deficit sandwiched between two skin islands
that replace palatal and nasal lining.
Above) Type IIIa defect. Note resection of all six walls of the maxilla, including the
floor of orbit and hard palate. The orbital contents have been preserved (left).
Resected specimen demonstrates the orbital floor, vertical maxillary buttresses, and
palatal resection (center, left). This creates a medium surface-area/medium volume
defect. Cranial or rib bone graft is used to reconstruct floor of orbit and is covered
with single-skin-island rectus abdominis myocutaneous flap (center, right). The rectus
abdominis myocutaneous flap (donor site depicted in inset) provides medium surface
area with medium volume. The bone graft is rigidly fixed to reconstruct the floor of
orbit. The rectus abdominis myocutaneous flap is inset with the skin island used to
close the roof of the palate, soft tissue to fill in midfacial defect, and muscle to cover
bone graft. Note extended length of deep inferior epigastric vessels to neck (right).
(Below) Patients who are not free-flap candidates may be reconstructed with split
calvarial bone grafts, covered with the temporalis muscle, transposed anteriorly. The
zygomatic arch should be osteotomized and removed temporarily to increase
excursion of the temporalis muscle.
(Above) Type IIIb defect. Note resection of all six walls of the maxilla, including the
floor of the orbit as well as orbital contents (left). Resected specimen demonstrates
resection of external eyelid, cheek skin, and orbital contents, in combination with
entire maxilla and palate (center, left). This creates a large surface area/large volume
defect. A three-skin-island rectus abdominis myocutaneous flap design is shown in
the inset. This flap provides multiple large surface areas with large volume of soft
tissue and muscle to fill in the defect (center, right). Rectus abdominis myocutaneous
flap (inset) demonstrates skin islands to resurface the external skin and palatal defect
with muscle and subcutaneous fat used to fill in soft-tissue deficit. If technically
feasible, a third skin island can be used to reconstruct the lateral wall of nose (right).
(Below) Type IV (orbitomaxillectomy) defect. Note resection of upper five walls of
maxilla, including the orbital contents but sparing the palate (left). Resected specimen
demonstrates resection of orbital contents, eyelid, and cheek skin, in continuity with
bone (center, left). This creates a large surface area/large volume defect. Note design
of single-skin-island rectus abdominis myocutaneous flap (depicted in inset). This
flap provides large surface area with large volume to reconstruct the defect (center,
right). Rectus abdominis myocutaneous flap in place, demonstrating skin island to
resurface the external skin defect with muscle and subcutaneous fat used to fill in the
soft-tissue deficit (right).
Combined nasal reconstruction
 Because the nose is not essential from the functional standpoint,
reconstructionshould be delayed.
 When the maxilla is resected in combination with the nose, the resulting defect is
massive.
 Local tissues (septum, nasal lining flaps, nasolabial flaps) that are usually used for
reconstruction of the nose are often unavailable.
 An additional free flap is often necessary to provide adequate tissues for lining and
support and often yields marginal aesthetic results.
 The quality of prostheses is so much better than with reconstructiont using the
paucity of local tissues (often irradiated). Most would advocate a prosthesis for
these patients. A delayed reconstruction of the nose can then be carefully planned
if indicated.