Phẫu Thuật Tạo Hình Grabb & Smith’s (Bản Cập Nhật – Kevin C. Chung)

Facial Nerve Injury
An accurate assessment of facial nerve function should be completed before injecting local anesthetic.
Frontal branch injuries are most likely to occur when a laceration crosses the line described by Pitanguy,
drawn from a point 0.5 cm inferior to the tragus to a point 1.5 cm superior to the lateral eyebrow.
Neurologic deficits from zygomatic and buccal branch injuries are less common, particularly when
lacerations occur medial to the lateral canthus because of the arborization that occurs medially, with
multiple nerve endings innervating a muscle. Buccal branch injuries are most likely to occur with large,
midcheek lacerations. Concomitant parotid duct injuries are common. The marginal mandibular nerve
has little redundancy and is most commonly injured as it crosses the inferior border of the mid-
mandibular body. Cervical branch injuries are less common and also exhibit crossover from multiple sub-
branches.
If facial nerve injury is suspected within a laceration, the wound should be explored in an attempt to tag
the cut ends proximally and distally. Stimulation of the distal cut end is possible up to 72 hours
postinjury; after this period of time, depletion of acetylcholine makes further stimulation impossible.
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Auricular Cartilage Injury
Lacerations that penetrate the auricular cartilage must take into account the limited vascularity of the
cartilage and the need to restore stability. Nonviable segments of cartilage or skin should be minimally
debrided and thoroughly irrigated. The cartilage and skin can usually be reapproximated in a single layer
due to the firm adherence of the skin to the cartilage. In adults, 5-0 polypropylene is an appropriate
suture choice, with 5-0 fast-absorbing gut reserved for children.
Hematoma and chondritis are two major concerns with ear injuries. Hematomas can be seen as ballotable
fluid collections between the perichondrium and cartilage. Prompt drainage is essential to avoid necrosis,
fibrosis, and deformed neocartilage formation, commonly known as cauliflower ear. After repair of an
auricular laceration or drainage of a hematoma, the ear should be bolstered for 5 to 7 days to prevent
hematoma formation or recurrence. A roll of petroleum-impregnated gauze placed on either side of the
ear and secured in place with polypropylene or nylon mattress sutures serves as an appropriate bolster.
Penetrating auricular injuries should receive 7 to 10 days of antibiotic prophylaxis, typically with
ciprofloxacin, to prevent chondritis. 12
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Canalicular Injury
Lacerations near the medial canthus of the eyelid should raise suspicion for injury to the superior and
inferior canaliculi. In these cases, consultation with ophthalmology is warranted. The canaliculi should be
probed acutely to determine if injury is present. Suture repair and stenting are commonly used
techniques for treatment.
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Septal Hematoma
Because cartilage receives its blood supply from the perichondrium, any collection of fluid between the
perichondrium and the cartilage will lead to cartilage destruction. The septum should always be
inspected with a nasal speculum and good lighting to evaluate for hematoma. A septal hematoma will
appear as a bulging, fluctuant collection along the septum. The collection should be aspirated with an 18-
gauge needle or lanced with an 11-blade scalpel, and nasal packing should be placed to prevent fluid
reaccumulation.
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Parotid Duct Injury
The parotid duct (Stenson duct) travels horizontally within the cheek, allowing the parotid gland to drain
intraorally through an opening on the buccal side of the second maxillary molar. Injury should be
suspected with lacerations to the cheek, particularly those that injure the buccal branch of the facial nerve,
as the nerve and duct travel in close proximity. A high index of suspicion is needed, because no
immediate signs of duct injury exist; the injury is usually noted days later when saliva begins draining
from the laceration. The intraoral orifice of the parotid duct can be cannulated with a pediatric
intravenous catheter and injected with methylene blue or saline to examine for injury. If the duct is
lacerated, repair should be conducted over a small-caliber pediatric feeding tube. The tube should be left
in place as a stent for 14 days. A subcutaneous drain left in place for 1 week and facial wrap providing
external pressure for the first 48 hours may also help prevent sialocele (Figure 36.6). 13
FIGURE 36.6 Suspected parotid duct injuries should be explored and repaired over a catheter if possible.
(Adapted with permission from Lewkowicz, AA, Hasson, O, Nahleili, O. Traumatic injuries to the parotid gland and duct. J Oral Maxillofac Surg. 2002;60:676-
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680.)
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Skeletal Injuries
Upper Facial Fractures
Frontal Sinus Fractures
The frontal bone is a particularly strong structure and is capable of withstanding more force than the
other facial bones. For this reason, frontal bone fractures signify high-energy traumatic mechanisms and
are often associated with intracranial injury.
Pneumatization of the frontal sinus begins around the age of 2 years and is completed by 12 years.
Because the bone is thicker in childhood, frontal sinus fractures are not commonly seen. In adults,
management of frontal sinus fractures depends on whether the fracture extends through the anterior or
posterior table or both, the degree of displacement, and the likelihood of nasofrontal outflow tract
obstruction (Figure 36.7).
FIGURE 36.7 Management of frontal sinus fractures. NFOT, nasofrontal outflow tract.
(Reproduced with permission from Rodriguez, ED, Stanwix, MG, Nam, AJ, et al. Twenty-six-year experience treating frontal sinus fractures: a novel algorithm
based on anatomical fracture pattern and failure of conventional techniques. Plast Reconstr Surg. 2008;122:1850-1866.)
Fractures of the anterior table may lead to visible or palpable contour irregularities of the forehead or
instability of the supraorbital bar. Posterior table fractures have the potential for dural tear, cerebrospinal
fluid leak, persistent pneumocephalus, or meningitis.
The nasofrontal outflow tract courses from the inferomedial frontal sinus in the most anterior and
superior extent of the anterior ethmoidal complex to exit in the middle nasal meatus at the hiatus
semilunaris. The nasofrontal outflow tract is likely to be injured with fractures to the inferomedial frontal
bone and the floor of the sinus. The tract may become obstructed with injury, leading to abscess or
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sinusitis. Evaluation of the fracture pattern and location on CT scan will indicate the likelihood of
nasofrontal tract involvement. Nasofrontal outflow tract involvement with obstruction is strongly
correlated with a higher degree of fracture displacement. 14
Several options for management exist. Nonoperative observation should include serial examinations and
CT scans to evaluate for mucocele or persistent pneumocephalus. Obliteration requires surgical curettage
of the sinus mucosa, burring of the sinus bone to remove any invaginations of mucosa, surgical occlusion
of the nasofrontal ducts, and placement of bone, muscle, fat, pericranial, or galeal flaps. Cranialization is
performed by removing the posterior table so the sinus and the anterior cranial fossa are contiguous. The
sinus mucosa must be carefully curetted, the inner portion of the anterior table bone burred away, and
the nasofrontal duct occluded with bone graft. The brain is allowed to fill what was formerly the frontal
sinus space over subsequent months.
Nondisplaced fractures of the anterior table or combined anterior and posterior tables without
nasofrontal outflow tract obstruction should be observed. Displaced fractures of only the anterior table
generally require operative reduction and fixation with low-profile miniplates to restore forehead
contour.
In posterior table fractures, the degree of displacement and presence of a cerebrospinal fuild (CSF) leak
dictate management. Displaced fractures carry a higher risk of dural tear, CSF leak, and meningitis. These
complications are minimized with obliteration for less severe fractures or cranialization for more
displaced or comminuted fractures.
With obstruction of the nasofrontal outflow tract in either anterior or posterior table fractures, the sinus
must be obliterated or cranialized regardless of the degree of fracture displacement. 14
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Complications
Abscesses can occur in acute or delayed fashion and can range from subcutaneous to intracranial. These
are managed with repeat surgical debridement and obliteration or cranialization. Mucoceles result from
the indolent overgrowth of residual basilar sinus mucosa from the diploic veins of Breschet, which are
small mucosal crypts that invaginate into the bone. Mucoceles typically present in a delayed fashion with
chronic headaches, mass effect, visual disturbance, nasal obstruction, or erosion of the frontal bone.
Mucoceles are difficult to treat; therefore, prevention is of primary importance.
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Midfacial Fractures
Orbital Fractures
The orbit is a thin-walled, conical, bony box in which the globe rests. Its structure is designed to support
the vertical and sagittal position of the globe, and to absorb blunt trauma to the upper midface to prevent
globe injury. With fractures to the medial wall or floor, the orbital space becomes contiguous with the
ethmoid or maxillary sinus, respectively, and the position of the globe may change. Fractures often
increase orbital volume, causing diplopia when the globe descends (vertical dystopia) or becomes
positioned deeper within the orbital cavity (enophthalmos).
Particularly in children, greenstick fractures of the floor can occur, allowing the inferior rectus muscle to
prolapse into the maxillary sinus with the bony fragment snapping back up into near original position
because of periosteal recoil. This muscular entrapment is a surgical emergency because the prolapsed
portion of the muscle quickly becomes ischemic. If the muscle is not released within 6 to 8 hours, it will
become fibrotic with a high risk of permanent diplopia. Retrobulbar hematoma can acutely increase
intraorbital pressure and quickly lead to optic nerve damage if not promptly diagnosed. Superior orbital
fissure and orbital apex syndromes can be associated with direct injury from fractured bone fragments or
with the subsequent retrobulbar hemorrhage (Figure 36.8; Table 36.3). Surgical reduction of these
posterior fracture fragments is generally met with limited success. Because the compression is often from
soft tissue, treatment is primarily medical, using high-dose corticosteroids. Some cases may resolve
spontaneously as edema subsides. 15
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FIGURE 36.8 In this patient with a small fracture of the orbital roof and lateral wall, the bone fragment caused orbital apex
syndrome with resultant blindness.
TABLE 36.3
Sequelae of Injuries to Periorbital Structures Associated With Orbital Fractures
Clinical Case
Presentation
Structures Involved
Entrapment
Pain during attempted upward gaze
Inferior oblique
Superior orbital fissure
(SOF) syndrome
Ptosis
CN III to levator palpebrae superioris
Proptosis
CN III; loss of retraction forces and bulge of flaccid
extraocular muscles
Ophthalmoplegia
CN III, IV, VI
Pupillary dilation, with loss of direct and
consensual light reflexes
Parasympathetic fibers of CN III
Loss of forehead sensation
V1 supratrochlear and supraorbital nerves
Loss of corneal sensation
V1 nasociliary branch
Orbital apex syndrome
Same as SOF syndrome, with the addition of
blindness
Same as SOF syndrome, with the additional involvement
of optic nerve (CN II)
Orbital fractures should be suspected with any substantial blunt trauma to the face, including a fall from
standing, blow to the face, or motor vehicle collision. Facial CT is the only method of ensuring accurate
diagnosis. Alignment of the orbital floor should be evaluated on coronal and sagittal cuts, and the
dimensions of the fracture in the anteroposterior and mediolateral directions should be measured. The
extraocular muscles can be examined on soft tissue windows to evaluate for entrapment; however, the
only way to accurately diagnose entrapment is by physical exam.
Diplopia is the primary surgical indication in orbital floor and medial wall fractures. Diplopia is more
likely to occur with larger fractures exceeding 1 to 2 cm2. 16,17 Often, when examined in the emergency
room, patients have already developed substantial periorbital edema masking the enophthalmos and
vertical dystopia that will result over time. Patients should be reexamined in 7 to 10 days, after the
swelling has subsided, to determine need for surgical intervention.
Once an incision is selected (Figure 36.9), dissection proceeds to the infraorbital rim; the periosteum of the
orbital floor and involved medial wall is lifted. At this point, an elevator can be used to identify the
borders of the fracture and a rim of stable bone surrounding the fracture (Figure 36.10). The optic nerve is
located approximately 32 to 42 mm posterior to the infraorbital rim 18 ; as dissection proceeds deeper into
the orbit, caution is used to avoid nerve injury. The elevator can be periodically removed to check the
position of its tip by grasping it at the infraorbital rim and measuring the distance from the tip to the
surgeon’s fingertip.
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FIGURE 36.9 Cross-sectional view of incisions for orbital floor exploration.
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FIGURE 36.10 When identifying the borders of an orbital floor fracture, an elevator can be used to palpate medially, laterally,
and posteriorly for a stable rim of bone.
A plate should be selected based upon fracture characteristics (Table 36.4). Complete coverage of the
defect is needed for larger fractures; an anatomic titanium plate with medial extension is often
appropriate for orbital floor fractures extending into the medial wall.
TABLE 36.4
Options for Orbital Implants19
Type
Benefit
Drawback
Autologous
bone
Biocompatible
Requires additional surgery at donor site
Unpredictable resorption
Inflexible; difficult to contour
Silastic sheets,
silicone
FlexibleEasy to use
Forms capsule prone to infection, seroma,
cysts, and sinus tracts
Porous
polyethylene
FlexibleEasy to useTissue ingrowth Reduces
foreign body reaction
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Risk of infection
Difficult removal with tissue ingrowth
Titanium
Rigid, yet malleableAble to
osseointegrate
Risk of
infection
With orbital roof fractures, the most pertinent concern is risk of a growing skull fracture in children who
have years of craniofacial growth ahead of them. Pulsation of the dura at the site of the fracture may
impair normal bone healing, allowing the fracture to expand with growth. In adults, indications for
reduction of orbital roof fractures are limited to patients with dural tears or orbital apex syndrome that
does not respond to medical therapy.
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Complications
Continued diplopia can result from inadequate reduction, or more specifically, inadequate restoration of
orbital volume. The orbital fat that prolapses into the maxillary sinus must be lifted back into the orbit
before placement of the plate to properly support the normal position of the globe. Diplopia can also
result from fibrosis of extraocular muscles or necrosis of the intraorbital fat from manipulation. 17
Lower eyelid malposition can include ectropion, scleral show, and entropion. Risk of ectropion and
scleral show increases with use of a transcutaneous incision; ectropion can complicate 14% of orbital floor
repairs approached through a subciliary incision. 20 A Frost stitch, placed through the lower lid tarsus and
secured to the forehead, helps elevate the lower lid for the first several days until edema subsides.
Although the Frost stitch can prevent acute globe exposure from chemosis, it has not been shown to
prevent ectropion. 21
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Zygomaticomaxillary Complex and Zygomatic Arch Fractures
Fractures of the zygomaticomaxillary complex (ZMC) are also referred to as tripod fractures. In fact, the
zygoma is a tetrapod structure that is stabilized by the zygomaticofrontal suture, zygomaticotemporal
suture, zygomaticomaxillary buttress, and the zygomaticosphenoid suture. 22 The zygomatic bone sets the
width and projection of the midface. Fractures typically displace the zygoma inferiorly, laterally, and
posteriorly, widening and flattening the face. Reduction is of paramount importance to restore midface
structure; therefore, most displaced fractures meet operative criteria. In addition, displacement of the
zygoma can impinge upon the coronoid process of the mandible and its associated muscles of
mastication, causing trismus, a limiting of mandibular excursion. Appropriate reduction alleviates
muscular impingement and restores mandibular motion.
The ZMC can be approached through transconjunctival and upper buccal sulcus incisions. Sometimes a
lateral canthotomy or an upper lid/lateral blepharoplasty incision is necessary as well, depending on the
degree of displacement. Reduction can be performed by placing an elevator or curved bone hook under
the body of the zygoma via the upper buccal sulcus incision and lifting the bone from its impacted
position. Alternatively, a Carroll-Girard bone screw (Figure 36.11) can be inserted percutaneously and
used to joy-stick the fracture into the desired position. Alignment must be determined at the
zygomaticofrontal, zygomaticomaxillary, and zygomaticosphenoid articulations. Of these, the
zygomaticosphenoid buttress is most important in verifying accurate realignment of the zygoma. The
zygomaticosphenoid buttress can be visualized through a lateral canthotomy extension of a
transconjunctival incision, or through a separate lateral rim incision. The buttresses are then stabilized
with titanium miniplates.
FIGURE 36.11 The Carroll-Girard screw can be anchored into the zygoma percutaneously and used to manipulate the bone.
In many cases, ZMC fractures are associated with fractures of the orbital floor. The ZMC must be reduced
first, as its alignment will be based on intact bone at the buttresses described above. The orbital floor
should then be checked for unmasking or widening of a fracture. Any significant fracture should be
repaired as previously described.
Isolated fractures of the zygomatic arch are problematic if they are depressed enough to affect facial
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contour or cause trismus. Direct exposure cannot be achieved through limited incisions, given the
conspicuous location and close association with the temporal branch of the facial nerve. For badly
displaced and comminuted fractures a coronal incision must be used, because this is the only approach
for the necessary access for plate fixation.
For depressed fractures with inherent stability, a Gillies approach may be used to reduce the fracture. A
2-centimeter horizontal incision is made within the hair-bearing portion of the temporal region 2.5 cm
anterior and superior to the helical root, after palpating and avoiding the temporal artery. Dissection
proceeds to the deep layer of the deep temporal fascia, which directly overlies the temporalis muscle. The
fascia is then incised, exposing the muscle. An elevator is inserted and directed inferiorly, just under the
zygomatic arch. Application of manual pressure reduces the fracture through this minimal access
technique.
Alternatively, the arch can be approached from a 2-centimeter upper buccal sulcus incision (Keen
incision) at the base of the zygomaticomaxillary buttress. The incision is made through the mucosa only,
allowing an elevator to be passed under the zygomatic arch that is in direct proximity to the incision.
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Nasal Bone Fractures
The nasal bones are the most commonly fractured facial bones, 23 accounting for over 55% of facial
fractures. 1,23 The nose serves both aesthetic and functional purposes, and dissatisfaction with nasal
appearance (13%–32%) and/or nasal airway patency (14%–36%) is high after fracture. 23
Fractures of the cartilaginous septum are particularly prone to nasal deformity and airway obstruction.
Even after closed reduction of the nasal bones, in the presence of an incomplete septal fracture, the bones
will tend to deviate toward the displaced portion of the septum during the healing process. 24 In addition
to restoring architecture of the nasal airway, reduction of the cartilaginous septum counteracts this
deforming force of the septum on the nasal bones and improves final alignment.
The nasal bones and septum can be reduced under local anesthesia depending on fracture complexity
and patient cooperation. Closed nasal reduction under general anesthesia has not been shown to have
superior outcomes to that under local anesthetic, 23 but may be more appropriate for anxious or young
patients, or more severely displaced fractures.
Regardless of the setting, the equipment and technique for closed nasal reduction are the same (Figure
36.12). Local anesthetic is injected within the soft tissue of the nasal dorsum to anesthetize the
infratrochlear nerves, around the infraorbital nerve, and along the base of the columella and nasal floor
(branches of the anterior and posterior ethmoidal nerves and sphenopalatine ganglion). Nasal pledgets
impregnated with a topical vasoconstrictor such as oxymetolazone or cocaine are inserted into each
nostril for 10 minutes and vasoconstriction is allowed to occur. To prevent inadvertent intracranial injury,
the distance from the external nasal aperture to the displaced nasal bone is measured by holding an
elevator on the exterior of the nose and grasping the distal portion of the elevator at the naris. The
elevator is then inserted and manual pressure applied while stabilizing the head and palpating the
displaced bones externally with the other hand. Once the nasal bones are reduced, the septum can be
grasped with Asch forceps and manipulated to its anatomic, median position.
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FIGURE 36.12 Closed nasal reduction can be accomplished with simple tools, including local anesthetic, oxymetolazone- or
cocaine-soaked pledgets, bayonet forceps, Killian nasal speculum, Boies elevator, and Asch forceps.
After manipulation of the septum, pressure should be applied to prevent septal hematoma. This can be
done by transseptal mattress sutures, or with Vaseline-impregnated gauze packing that is left in place for
24 hours. Alternatively, silicone septal splints, such as Doyle or bivalve splints, can be sutured in place for
5 to 7 days. The nasal dorsum should be stabilized with an external thermoplastic splint. Curing of the
thermoplastic material is an exothermic process, so the thin nasal skin should be protected with a layer of
surgical tape to prevent skin burns. Because the nasal bones are reduced but not fixated, a too-tight splint
may cause bony displacement.
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Nasoorbitoethmoidal Fractures
The nasoorbitoethmoidal (NOE) complex is an area of thin bone in the upper midface that encompasses
the superior nasal cavity and ethmoidal air cells. It is bordered superiorly by the frontal sinus, cribriform
plate, and anterior skull base; anteriorly by the nasal bones, frontal process of the maxilla, and nasal
process of the frontal bone; laterally by the lacrimal bone and lamina papyracea of the ethmoid bone; and
medially by the septum and the perpendicular plate of the ethmoid. The thin bones of the anterior cranial
fossa at the fovea ethmoidalis and the tight dural adhesion at the cribriform plate make NOE fractures
particularly susceptible to CSF leak. The medial canthal tendon attaches the tarsal plates and the
orbicularis oculi to the medial orbital wall, inserting onto the anterior and posterior lacrimal crests. The
medial canthal tendon sets the intercanthal distance and the angle of the palpebral fissure.
NOE fractures are often the result of high-impact injuries to the midface. Comminution and instability are
typical. Classification is based upon the involvement of the central fragment, or the fragment of bone to
which the medial canthal tendon attaches. 25 Class I NOE fractures involve a single central fragment with
relative stability (Figure 36.13A). In class II NOE fractures comminution is present, but the medial canthal
tendon remains attached to a central fragment that is large enough for stabilization with a miniplate or
microplate (Figure 36.13B). Class III fractures are characterized by detachment of the medial canthal
tendon from bone, extensive bony loss, or a high degree of bony comminution such that fixation cannot
be accomplished with traditional measures (Figure 36.13C).
FIGURE 36.13 Nasoorbitoethmoid fractures can be divided into types I (A), II (B), and III (C).
Management is dictated by the fracture type. Class I fractures are stabilized with miniplates at the
frontomaxillary, zygomaticomaxillary, and medial maxillary buttresses. Placement of miniplates for class
II fractures is similar to class I, with the addition of miniplates or microplates for stabilization of the
central fragment. In some class II and all class III fractures, instability of the medial canthal tendon
requires transcanthal wiring. A 3-0 stainless steel wire is passed from a point superior and posterior to the
medial canthal attachment through holes drilled to the contralateral medial orbital wall. In some cases,
placement of a bone graft is necessary beforehand to attain bony stability sufficient to support the wire.
Adequate restoration of the tendon attachment is critically important to avoid alteration of the palpebral
fissure or telecanthus. Vertical asymmetry of as little as 2 mm is noticeable at conversational distance. The
medial canthi should be positioned no more than 25 mm apart. Transcanthal wires placed anterior to the
medial canthal attachment site will not prevent lateral migration of the canthus, thus leading to
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permanent telecanthus and a broad nasal base. Often, multiple surgical approaches are necessary to attain
proper fracture reduction.
Management of soft tissue edema is of equal importance as bony reduction. Subperiosteal seroma,
hematoma, or postoperative edema can lead to permanent soft tissue thickening, which effaces the
normal contours of the nasoorbital region. Splinting with a padded metal bolster is recommended. The
splint is fixated with transcanthal wires designed for soft tissue support alone. Careful monitoring is
required to avoid soft tissue pressure injury during the period of postoperative edema.
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Maxillary Fractures
The French surgeon René Le Fort classified three patterns of maxillary fractures that result from blunt
trauma to the adult facial skeleton. A key component of each fracture type is the disruption of the
ipsilateral pterygoid plates, which are a major source of midfacial stability. The LeFort fracture
classification scheme should be used as a guideline, as true fracture patterns are often combinations of the
classic patterns and are most accurately described using anatomic terms. Fracture patterns may differ on
each side of the face. In these cases, the term hemi-LeFort is often used.
LeFort I fractures occur in a horizontal pattern parallel to the occlusal plane, extending from the piriform
aperture laterally through the pterygomaxillary junction (Figure 36.14). LeFort II fractures are pyramidal,
extending from the pterygomaxillary junction through the zygomaticomaxillary buttress and orbital floor
obliquely to the nasofrontal junction. LeFort III fractures are horizontally-oriented fractures through the
upper midface that produce a separation of the cranium from the face, termed craniofacial disjunction.
These fractures extend from the zygomatic arch, through the pterygomaxillary junction, lateral orbital rim
and orbital roof, to the nasofrontal junction.
FIGURE 36.14 A. LeFort I fractures occur transversely across the maxilla. B. LeFort II fractures have a pyramidal pattern. C.
LeFort III fractures represent a craniofacial disjunction.
Although LeFort I fractures may be treated through an upper buccal sulcus incision, LeFort II and III
fractures benefit from the exposure of a coronal approach. Reduction can be accomplished with Rowe
disimpaction forceps. Restoring normal occlusion is the primary goal of reduction; normal facial width,
height, and projection should follow secondarily. Facial stability is restored by placing plates along the
involved facial buttresses. LeFort fractures are typically the result of high-energy trauma and are rarely
isolated fractures. In these cases, sequencing of fracture reduction becomes an important consideration.
Palatal fractures usually occur in the sagittal plane, splitting the alveolar ridge between the central
incisors or between the lateral incisor and canine. Alternatively, the maxillary tuberosity containing the
molars may be split from the rest of the alveolar ridge. Palatal fractures often occur in conjunction with
LeFort I fractures. After reduction, stability can be restored anteriorly with a miniplate in the area of the
piriform, and posteriorly with a plate across the palatal concavity for maintenance of palatal width.
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Lower Facial Fractures: The Mandible
Biomechanics
The biomechanical properties of the mandible are the most complex of the facial skeleton. The mandible
acts as a curved beam, supported on its ends by the muscular pterygomasseteric sling. The masseter and
temporalis function to elevate the mandible and create a strong bite force. The medial and lateral
pterygoids protrude the mandible and help with opening, or excursion. The suprahyoid muscles,
comprised of the digastric, stylohyoid, mylohyoid, and geniohyoid muscles, function to elevate the hyoid
and base of tongue during deglutition, and depress the mandible. In the fractured mandible, the muscles
of mastication displace the posterior segment superiorly, whereas the suprahyoid muscles pull the
anterior segment inferiorly. 26
During mastication, external downward forces exerted by tooth-to-tooth contacts cause surrounding
areas of compression balanced by the tension created either contralaterally or posteriorly by the upward
pull of the muscles of mastication. The areas of tension and compression are dependent on the site of
mandibular loading.
The mandible can also be thought of as a ring structure, articulating with the temporal bone at the TMJs.
Similar to opening the rings of a binder, the mandibular ring is often disrupted through faults created in
at least two areas. About 1/2 to 2/3 of mandibular fractures involve fractures at multiple sites. 27,28
Commonly, an anterior impact such as in a motor vehicle collision will result in condylar, symphyseal,
and parasymphyseal fractures, whereas a lateral impact from assault will fracture the body and
contralateral angle. 27
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Principles of Management
The most important objective in treating mandibular fractures is restoration of normal occlusion;
anatomic reduction is a secondary goal. Stable, nondisplaced fractures may be treated nonoperatively
with a soft diet. Sometimes, partially luxated teeth will prevent fracture reduction and will obscure
normal occlusion; in these cases, teeth in the line of the fracture must be extracted. Tooth extraction is also
recommended whenever the tooth roots are fractured.
Given the normal biomechanical loads exerted on the mandible, types of fixation fall into two categories:
rigid and functionally stable. In rigid fixation (load-bearing), no micromotion is translated through the
fracture site and primary bone healing occurs. This type of fixation bears more mechanical forces of the
mandible and is useful if healing is delayed, such as in atrophic bone, bony defects, smokers, poor oral
hygiene, or patients with multiple comorbidities. An example is a reconstructive plate applied to the
inferior mandibular border. In functionally stable fixation (load-sharing), micromotion is allowed at the
fracture site, and a bony callus forms during the process of secondary bone healing. Miniplates rely on
the accumulation of bone at the fracture site to share mandibular loading before they become prone to
fatigue failure. Examples of load-sharing fixation include a Champy plate along the external oblique
ridge, a lower border miniplate with maxillomandibular fixation (MMF), or upper and lower border
miniplates with monocortical screw fixation. In addition to plates, MMF uses contact at the apices of the
teeth to serve as another point of functionally stable fixation. 28 In the multiply fractured mandible, at
least one fracture site should be treated with heavier, more rigid plates due to the increased complexity of
biomechanical stress forces.
Because of the curved nature of the mandible, locking plates are often desirable. Screws that lock to the
plate fixate the plate in the position in which it was placed by the surgeon with lower risk of displacing
the fracture fragments. Conversely, nonlocking screws can lag the plate into closer coaptation with the
bone. Although the lag concept is useful in other anatomic areas, its use in the mandible can displace the
fracture of the curvilinear bone and lead to malocclusion. Non-locking screws are typically only used in
oblique mandibular fractures, and lag screws are usually only used at the symphysis.
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Symphyseal and Parasymphyseal Fractures
The mandibular symphysis lies between the apices of the central incisors and is characterized by thick
bone and short incisor tooth roots. The parasymphysis is defined by the lateral border of the central
incisor root and the lateral border of the canine. A fixation technique unique to the symphysis is the
placement of two bicortical lag screws in the coronal plane, perpendicular to the line of the fracture. A
lower border plate is a common method of symphyseal or parasymphyseal fixation. This can be placed
with bicortical screws below the level of the tooth apices for added stability. Rigid fixation can be attained
with the addition of an upper border plate with monocortical screws. MMF is usually preferable as an
extra point of stability.
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Body and Angle Fractures
The mandibular body extends from the lateral canine to the medial border of the third molar. The body
conducts the inferior alveolar nerve to the mental foramen, typically located between the first and second
premolars where it exits as the mental nerve. The body contains longer tooth roots, the longest of which is
the canine. During fracture fixation, avoiding injury to the inferior alveolar nerve and tooth roots is
critical.
The angle contains the third molars and connects the body with the ramus. The body and angle
experience tensile forces along the upper border and compression along the inferior border under axial
loads. A neutral zone exists centrally, along the neurovascular canal. Methods of fixation take these
biomechanical properties into account (Table 36.5). Fractures of the angle have the highest incidence of
complications, particularly in the presence of partially erupted or impacted third molars. 28,29
TABLE 36.5
Options for Mandibular Fixation. By Convention, Plates are Named According to the Outer Diameter of the Screws They
Accommodate
Region
Rigid Fixation
Functionally Stable Fixation
Symphysis, parasymphysis
Locking reconstructive plate
(2.8 mm)
Two lag screws (2.4 mm)
Lower border plate + upper border plate
(2.0 mm each)
Body
Lower border plate (2–2.4 mm) + maxillomandibular
fixation (MMF)
Lower border plate + upper border plate (2 mm
each) ± MMF
Single monocortical miniplate in the central neutral zone
(2 mm) + MMF
Angle
Champy plate (2 mm tension band across oblique
ridge) + MMF
Champy plate + lower border plate (2 or 2.4 mm) ± MMF
Condyle, subcondylar region
N/A
MMF
Two miniplates (1.5 or 2 mm)
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Subcondylar and Condylar Fractures
Fractures of the condylar head and subcondylar region are common, accounting for 25% to 35% of
mandibular fractures in adults. 26 Loss of condylar height presents with early posterior tooth contact
ipsilaterally and an anterior open bite. Risks of open treatment include facial nerve palsy, scarring, and
inadequate reduction. Due to the high incidence of stiffness with an open approach, condylar and
subcondylar fractures are often treated in a closed fashion. Normal occlusion is established and stabilized
with MMF for 2 to 3 weeks. Open treatment is best reserved for displaced fractures without comminution
and requires specific training and experience on the part of the surgeon.
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Complications
Malocclusion can result from insufficient reduction or loss of reduction during the healing process due to
inadequate fixation, poor bone quality, or suboptimal patient compliance. This may cause malunion or
nonunion. Injury to tooth roots can occur from drilling or placement of bone screws. Facial nerve injury
may result from a Risdon incision (marginal mandibular nerve) or condylar approaches (main trunk or
any of its branches). Paresthesias can occur if the inferior alveolar or mental nerves are injured; even
without transection, neuropraxia is common due to traction of the nerve. Stiffness of the TMJ can result
from inadequate seating of the condyle during fixation, condylar head fracture, or prolonged MMF.
Hardware infection may be managed with a period of observation and antibiotics with or without
surgical irrigation; ideally, hardware removal is delayed until union occurs.
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Panfacial Fractures
The definition of panfacial fractures is variable in the literature, at times referring to fractures spanning
each third of the face, and at other times indicating fractures involving the maxilla, mandible, and ZMC.
30,31 With panfacial fractures, the face assumes a spherical shape, with loss of vertical height, reduction in
anteroposterior projection, and increase in facial width. Extensive facial fractures are the result of high-
energy trauma, and comminution is expected. Plastic surgeons must recognize mechanisms of injury that
suggest risk of concomitant injuries and consult the trauma team when warranted.
Restoration of facial dimensions must build from a stable, known skeletal base as a reference point. This
can be sequenced in a top-down, bottom-up, or inside-out fashion. The most common sequence involves
rebuilding the skeleton upwards after restoring mandibular stability. Restoring the preinjury occlusion
with MMF allows the occlusal subunit to function as one, and ZMC and NOE fractures can be reduced
from this reference point. Alternatively, the surgeon can work downwards from a noninjured cranial base
and zygomaticofrontal suture. Primary bone grafting may be necessary to replace devitalized or highly
comminuted bone.
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Questions
1. A 14-year-old boy presents to the emergency department after an unwitnessed ATV accident in
which he was found lying without a helmet on the trail. He complains of jaw pain and his right eye is
swollen shut. What is the best next step in management?
a. Maxillofacial CT scan with 1.0 mm cuts
b. Evaluation of extraocular motions to rule out entrapment
c. Adherence to spinal precautions and palpation of the neck for tenderness
d. Checking occlusion to compare to the patient’s baseline
2. Which of the following is most likely to lead to late deformity?
a. Bilateral subcondylar mandible fractures
b. Comminuted nasoorbitoethmoidal fracture with canthal bowstringing
c. Nasal bone fracture with septal deviation
d. Zygomaticomaxillary complex fracture without displacement at the lateral orbital rim
3. A 23-year-old man presents to the emergency department with multiple stab wounds. His facial
lacerations were not fully evaluated during his workup. Which of the following are appropriate
combinations of injury location and long-term complications?
a. Floor of mouth; Stenson duct leak
b. 1 cm inferior to the auricular lobule; lack of ipsilateral lower lip depression while smiling
c. Lateral infraorbital rim; inability to elevate ipsilateral eyebrow
d. Central and medial lower eyelid; epiphora
4. Which fracture is most likely to require operative intervention?
a. Anterior table frontal sinus fracture with obstruction of the nasofrontal duct
b. Orbital roof fracture extending into the lateral wall
c. Orbital floor fracture 1 cm in diameter in a patient without diplopia
d. Concomitant LeFort I and ipsilateral ZMC fractures with normal occlusion
5. A 50-year-old woman sustains panfacial fractures in a high-speed motor vehicle collision in which
she was the unrestrained passenger. Which is the most appropriate sequencing of fracture reduction
and fixation?
a. ZMC, orbital floor, mandibular angle, LeFort I, anterior table of the frontal sinus
b. Anterior table of the frontal sinus, LeFort I, mandibular angle, orbital floor, ZMC
c. Mandibular angle, LeFort I, ZMC, orbital floor, anterior table of the frontal sinus
d. Anterior table of the frontal sinus, orbital floor, ZMC, LeFort I, mandibular angle
6. You are reviewing the postoperative course of your most recent four operative mandible fractures.
Which patient is the most likely to have had complications?
a. 21-year-old man with right angle fracture sustained during an altercation
b. 34-year-old woman with bilateral subcondylar fractures from a motor vehicle accident
c. 18-year-old boy with symphyseal fracture after an ATV accident
d. 31-year-old man with subcondylar and contralateral body fracture after falling from a roof
1. Answer: c. Many patients whose mechanism of injury is sufficient to produce facial fractures are
also at risk of more significant multisystem traumatic injuries. Evaluation must first focus on airway,
breathing, circulation, and disability. Almost 10% of patients with facial fractures will have
concomitant cervical spine injuries. Protecting the spine in at-risk patients must be a priority until the
spine can be cleared. The remaining actions would be appropriate after serious concomitant injuries
are ruled out. Priority should be placed on ruling out plastic surgical emergencies, including
entrapment of the extraocular muscles which is diagnosed clinically by physical exam. Workup
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would also include a careful examination to determine occlusion status and a maxillofacial CT scan
with thin cuts.
2. Answer: b. NOE fractures are notoriously difficult to treat. The central midface lacks sagittal
buttresses to support adequate projection, giving the region a high propensity to heal in a depressed
position. The medial canthal tendon inserts into the thin bone of the medial orbit and establishes the
appropriate intercanthal distance. When canthal bowstringing is present, the surgeon must
determine whether the bone fragment to which the medial canthal tendon attaches is stable enough
to fixate with miniplates. If the fragment is too small or comminuted transcanthal wiring will be
necessary, with or without primary bone grafting. NOE fractures have a high incidence of late
deformity. Bilateral subcondylar mandible fractures are commonly treated with maxillomandibular
fixation, with the greatest concern of inadequate treatment being a late anterior open bite. Both nasal
bone and septal fractures can be reduced and stabilized more easily than the thin bones of the NOE
region. The ZMC is unlikely to be displaced if the zygomaticofrontal buttress at the lateral orbital rim
remains well aligned.
3. Answer: d. Lacerations of the medial upper or lower eyelid may involve the canalicular system. If
canalicular injury is suspected, ophthalmologic consultation is warranted to probe and repair or
bypass the ductal system. Untreated canalicular injury may lead to excessive eye tearing, or
epiphora. Injury to the parotid duct (Stenson duct) should be suspected with deep cheek lacerations.
The duct travels from the anterior parotid gland through the midcheek in close proximity to the
buccal branch of the facial nerve to open into the oral cavity adjacent to the second maxillary
premolar. A laceration to the floor of the mouth would risk injuring other salivary glands but the
Stenson duct. Inability to depress the lower lip while smiling is characteristic of a marginal
mandibular nerve injury. This branch of the facial nerve exits with the main trunk from the
stylomastoid foramen 1 cm anterior and inferior to the tragal pointer. It is part of the inferior or
cervicofacial division that separates from the temporofacial division within the parotid gland and
then divides from the cervical branch at the pes anserinus. The nerve travels anteriorly along the
mandibular body or 1 to 2 cm below the lower mandibular border to innervate the mentalis and
produce lower lip depression. A laceration directly inferior to the lobule would be too posterior to
injure this branch. The temporal branch of the facial nerve innervates the frontalis and is responsible
for brow elevation. This branch separates from the main trunk as part of the temporofacial division.
The temporal branch is at highest risk of injury along a line drawn from 0.5 cm inferior to the tragus
to 1.5 cm superior to the lateral eyebrow, known as the Pitanguy line. A laceration at the lateral
infraorbital rim would be too medial to injure this branch.
4. Answer: a. Frontal sinus fractures that involve the nasofrontal duct have a high incidence of
complications. These fractures should be treated by cranialization or obliteration to avoid mucocele
or abscess formation. Orbital roof fractures are often managed nonoperatively, unless they create
dural tears and cerebrospinal fluid leaks at the anterior cranial base. Indications for orbital floor
repair include diplopia and entrapment. No definitive size cutoff exists over which an operative floor
fracture requires fixation, although fractures larger than 1 to 2 cm2 are more likely to be associated
with persistent diplopia. Maxillary fractures meet operative criteria if they are displaced or unstable.
A primary indication of displacement is malocclusion. Nondisplaced LeFort I and ZMC fractures can
be managed with a soft diet and close observation.
5. Answer: c. Panfacial fractures distort many of the landmarks typically used for fracture reduction,
so sequencing fracture reduction and fixation is critical. Strategies that build from known to
unknown in a top-down or bottom-up fashion are most likely to be successful. In the patient
presented, the mandibular condyles can be used as stable reference points to reduce the mandibular
angle fracture; then place the patient in MMF and reduce the LeFort I fragment using the teeth as a
point of reference. Of note, the ZMC should be reduced and fixated prior to the orbital floor because
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ZMC reduction may change the size and orientation of the orbital floor fracture but not vice versa. In
this patient, a top-down strategy would also be effective, but the ZMC must be addressed before the
orbital floor fracture.
6. Answer: a. Multiple studies have demonstrated that fractures of the mandibular angle have the
highest incidence of complications. The presence of the inferior alveolar nerve, impacted third
molars, and opposing muscle forces make this region more challenging to treat. Risk of infection is
slightly heightened if a wisdom tooth is present within the fracture line. The other fracture patterns
are not specifically associated with an increased risk of complications. Complications are also more
likely to be experienced in ballistic injuries, edentulous patients, and smokers.
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References
Allareddy, V, Allareddy, V, Nalliah, RP. Epidemiology of facial fracture injuries. J Oral Maxillofac Surg. 2011;69:2613-2618.
Mithani, SK, St Hilaire, H, Brooke, BS, et al. Predictable patterns of intracranial and cervical spine injury in craniomaxillofacial trauma:
analysis of 4786 patients. Plast Reconstr Surg. 2009;123:1293-1301.
Manson, PN, Clark, N, Robertson, B, et al. Subunit principles in midface fractures: the importance of sagittal buttresses, soft-tissue
reductions, and sequencing treatment of segmental fractures. Plast Reconstr Surg. 1999;103:1287-1306.The authors present a classic description
of how facial buttresses influence the technique and outcome of midfacial fracture reduction. Common pitfalls are addressed with recommendations as to
how secondary complications can be avoided.
Manson, PN, Hoopes, JE, Su, CT. Structural pillars of the facial skeleton: an approach to the management of Le Fort fractures. Plast Reconstr
Surg. 1980;66:54-61.
Zide, BM, Swift, R. How to block and tackle the face. Plast Reconstr Surg. 1998;101:840-851.
Eppley, BL, Custer, PL, Sadove, AM. Cutaneous approaches to the orbital skeleton and periorbital structures. J Oral Maxillofac Surg.
1990;48:842-854.
Mundinger, GS, Borsuk, DE, Okhah, Z, et al. Antibiotics and facial fractures: evidence-based recommendations compared with experience-
based practice. Craniomaxillofac Trauma Reconstr. 2015;8:64-78.
Brooke, SM, Goyal, N, Michelotti, BF, et al. A multidisciplinary evaluation of prescribing practices for prophylactic antibiotics in operative
and nonoperative facial fractures. J Craniofac Surg. 2015;26:2299-2303.
Chole, RA, Yee, J. Antibiotic prophylaxis for facial fractures: a prospective, randomized clinical trial. Arch Otolaryngol Head Neck Surg.
1987;113:1055-1057.
Ellis, E. Antibiotics and mandibular fracture update. J Oral Maxillofac Surg. 2016;74:1911-1912.
Zix, J, Schaller, B, Iizuka, T, Lieger, O. The role of postoperative prophylactic antibiotics in the treatment of facial fractures: a randomised,
double-blind, placebo-controlled pilot clinical study. Part I: orbital fractures in 62 patients. Br J Oral Maxillofac Surg. 2013;51:332-336.
Thill, MP, Horoi, M, Ostermann, K, et al. Acute external ear lesions: clinical aspects, assessment, and management. B-ENT. 2016;26:155-
171.This article provides a detailed, comprehensive approach to auricular hematoma, perichondritis, laceration, and burn with treatment algorithms for
each clinical problem.
Lewkowicz, AA, Hasson, O, Nahleili, O. Traumatic injuries to the parotid gland and duct. J Oral Maxillofac Surg. 2002;60:676-680.A literature
review was conducted to supplant the experience of a single center in treating traumatic injuries to the parotid duct. An algorithm for treatment is
proposed.
Rodriguez, ED, Stanwix, MG, Nam, AJ, et al. Twenty-six-year experience treating frontal sinus fractures: a novel algorithm based on
anatomical fracture pattern and failure of conventional techniques. Plast Reconstr Surg. 2008;122:1850-1866.This article reviews 857 cases of
frontal sinus fractures treated at a tertiary hospital. A treatment algorithm is proposed, and the incidence of complications is described within the
framework of the proposed algorithm.
Chen, CT, Chen, YR. Traumatic superior orbital fissure syndrome: current management. Craniomaxillofac Trauma Reconstr. 2010;3:9-16.
Manson, PN, Grivas, A, Rosenbaum, A, et al. Studies on enophthalmos: II. the measurement of orbital injuries and their treatment by
quantitative computed tomography. Plast Reconstr Surg. 1986;77:203-214.
Chaudry, O, Isakson, M, Franklin, A, Maqusi, S, El Amm, C. Facial fractures: pearls and perspectives. Plast Reconstr Surg. 2018;141:742e-
758e.This review article discusses concepts in treating facial fractures primarily and managing secondary complications. Multiple videos are available
online with further detail on fracture management and surgical techniques.
Danko, I, Haug, RH. An experimental investigation of the safe distance for internal orbital dissection. J Oral Maxillofac Surg. 1998;56:749-752.
Mok, D, Lessard, L, Cordoba, C, et al. A review of materials currently used in orbital floor reconstruction. Can J Plast Surg. 2004;12:134-140.
Al-Moraissi, EA, Thaller, SR, Ellis, E. Subciliary vs. transconjunctival approach for the management of orbital floor and periorbital fractures:
a systematic review and meta-analysis. J Craniomaxillofac Surg. 2017;45:1647-1654.
Bartsich, S, Yao, CA. Is frosting effective? The role of retention sutures in posttraumatic orbital reconstruction surgery. J Plast Reconstr Aesthet
Surg. 2015;68:1683-1686.
Lee, EI, Mohan, K, Koshy, JC, Hollier, LH. Optimizing the surgical management of zygomaticomaxillary fractures. Semin Plast Surg.
2010;24:389-397.
Basheeth, N, Donnelly, M, Smyth, D, Shandilya, M. Acute nasal fracture management: a prospective study and literature review.
Laryngoscope. 2015;125:2677-2684.
Rohrich, RJ, Adams, WP. Nasal fracture management: minimizing secondary nasal deformities. Plast Reconstr Surg. 2000;106:266-273.
Markowitz, BL, Manson, PN, Sargent, L, et al. Management of the medial canthal tendon in nasoethmoid orbital fractures: the importance of
the central fragment in classification and treatment. Plast Reconstr Surg. 1991;125:843-853.This landmark article describes the classification
system for NOE fractures and a detailed treatment strategy for reduction and fixation of each type.
Morrow, BT, Samson, TD, Schubert, W, Mackay, DR. Evidence-based medicine: mandible fractures. Plast Reconstr Surg. 2014;134:1381-1390.
King, RE, Scianna, JM, Petruzzelli, GJ. Mandible fracture patterns: a suburban trauma center experience. Am J Otolaryngol. 2004;25:301-307.
Ellis, E, Miles, BA. Fractures of the mandible: a technical perspective. Plast Reconstr Surg. 2007;120:76S-89S.This introductory article describes the
biomechanics of the mandible as related to fracture fixation. Techniques of osteosynthesis in each region of the mandible are discussed in detail, along
with depictive photographs and radiographs.
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Chuong, R, Donoff, RB, Guralnick, WC. A retrospective analysis of 327 mandibular fractures. J Oral Maxillofac Surg. 1983;41:305-309.
He, D, Zhang, Y, Ellis, E. Panfacial fractures: analysis of 33 cases treated late. J Oral Maxillofac Surg. 2007;65:2453-2465.
Kelly, KJ, Manson, PN, Vander Kolk, CA, et al. Sequencing LeFort fracture treatment (organization of treatment for a panfacial fracture). J
Craniofac Surg. 1990;1:168-178.
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C H A P T E R 3 7
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Head and Neck Cancer and Salivary Gland
Tumors
Matthew M. Hanasono and Brian A. Moore
Key Points
Alcohol and tobacco use are the two most important risk factors for head and neck cancer,
particularly cancers of the oral cavity, oropharynx, hypopharynx, and larynx, whereas human
papillomavirus is increasingly recognized as a risk factor for oropharyngeal cancer.
Treatment for head and neck cancer depends on the location of the tumor and the stage and can
include surgery, radiation, chemotherapy, and/or targeted therapy.
Cervical lymphadenectomy (neck dissection) is indicated for nodal disease and cancers at high risk
for regional spread.
About 80% of salivary gland tumors occur in the parotid glands, followed by the submandibular and
minor salivary glands, and only about 1% occur in the sublingual glands.
About 80% of parotid gland tumors are benign, and the parotid gland is the most common location
for salivary gland malignancies; about 50% of submandibular gland tumors and 80% of minor
salivary gland tumors are malignant.
This chapter will provide an overview to cancer staging and treatment of the upper aerodigestive tract
(UADT), including the oral cavity, pharynx, and larynx, and the salivary glands. Although a
comprehensive text is not possible in this space, our goal is to provide the reconstructive surgeon with
adequate knowledge to communicate with the ablative surgeon and anticipate the surgical defect. Being
able to predict the surgical defect helps the reconstructive surgeon to plan the reconstruction
appropriately. Furthermore, knowledge of the cancer’s biology and current recommended treatment
assists the surgeon to factor in the possible need for adjuvant therapy, such as radiation, as well as get a
sense of the patient’s prognosis, both of which may affect choice of reconstructive techniques to be
performed.
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Upper Aerodigestive Tract Cancers
Over 95% of UADT tumors are squamous cell carcinomas (SCCs). 1 Overall, 5-year survival for these
cancers is about 65% but varies substantially based on site, stage, and histologic findings. 2 Other cancers
affecting the UADT include salivary gland malignancies, sarcomas, mucosal melanomas, and
lymphomas.
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Anatomy
The anatomic subsites of the oral cavity include the labial mucosa, buccal mucosa, floor of mouth,
alveolar ridge and gingiva, anterior two-thirds of the tongue (anterior to the circumvallate papillae), hard
palate, and retromolar trigone (Figure 37.1). The oropharynx lies posterior to the oral cavity and consists
of the soft palate, base of tongue (posterior to the circumvallate papillae), palatine tonsils, palatoglossal
folds, valleculae, and posterior pharyngeal wall. The nasopharynx is superior to the oropharynx and
includes the mucosa over the posterior body of the sphenoid and basilar part of the occipital bone
superiorly, the adenoids and pharyngobasilar fascia posteriorly, and the Eustachian tubes and the lateral
pharyngeal recesses (fossae of Rosenmüller) laterally. The hypopharynx spans from the hyoid bone down
to the inferior cricoid cartilage and includes the piriform sinuses, postcricoid area, and the pharyngeal
wall. The larynx comprises the supraglottis, glottis (vocal folds), and subglottis.
FIGURE 37.1 Upper aerodigestive tract (UADT) sites and subsites.
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Incidence and Risk Factors
Tobacco is a major risk factor for UADT SCC. A meta-analysis by Gandini et al. 3 found a relative risk of
3.4 for oral cavity and 6.8 for oropharynx SCC in current tobacco smokers compared with nonsmokers.
Tobacco and concomitant alcohol consumption synergistically increase the risk 10- to 15-fold. Alcohol has
also been shown by many studies to be an independent risk factor. 4 Smokeless tobacco and betel nut also
significantly increase the risk for oral cavity cancers. Although lip cancers are included in the oral cavity
cancer staging system, they are different in that sun exposure is highly correlated with their development.
Leukoplakia (white patches) and erythroplakia (red patches) in the oral cavity are considered
premalignant lesions but may harbor dysplasia or malignancy on histology evaluation up to 20% and
over 50% of the time, respectively. 4
Besides tobacco and alcohol, human papillomavirus (HPV) has been recognized as a major etiologic
factor in SCCs of the oropharynx and is felt to be the cause of the rise in incidence of this cancer over the
past 20 years. Recent studies suggest that HPV-associated cancers account for 73% of oropharyngeal
SCCs, representing an increase of 225% between 1988 and 2004. 5,6 Compared with patients with HPV-
negative tumors, patients with HPV-associated cancers tend to be younger, healthier, and have a better
prognosis; middle-aged men with limited to no smoking history constitute the most commonly affected
demographic. 7 HPV is the most common sexually transmitted infection, and certain subtypes, most
commonly HPV-16, are associated with the development of malignancy in the oropharynx as well as of
the cervix and anogenital tract. SCCs of the oropharynx can be tested for HPV positivity using
immunohistochemical stains to identify p16 protein (cyclin-dependent kinase 2A, a tumor suppressor
protein that is overexpressed in HPV-associated oropharyngeal cancer) or HPV DNA or RNA to help
convey prognostic information to the patient. Because of its lower cost and ease of testing, p16
immunohistochemistry has evolved as an acceptable surrogate marker for HPV-associated cancers. 8 HPV
vaccination in adults after the diagnosis of HPV-positive oropharyngeal SCC is not felt to be of any
benefit, but there is apparent benefit in primary disease prevention if administered to boys and girls
according to established guidelines. 7,9
Nasopharyngeal cancer (NPC) is most common in southern China and other parts of Southeast Asia and,
in endemic regions, is strongly associated with the presence of Epstein-Barr virus (EBV). Salt-cured fish
and meats, rich in nitrosamines, which are popular in some Asian countries, have also been linked to
NPC. Tobacco and alcohol use may also be risk factors, but the link is less clear.
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Preoperative Considerations
Biopsies, Imaging, and Metastatic Workup
Following thorough history and physical examination, suspicious lesions of the UADT should be
biopsied. Because of the relatively high risk of synchronous primary cancers, panendoscopy
(laryngoscopy, bronchoscopy, and esophagoscopy) is often performed as part of the workup. Computed
tomography (CT) helps identify nodal metastases as well as bony invasion, which is important for staging
and surgical planning. If there is a question regarding the extent of soft tissue involvement or perineural
spread, magnetic resonance imaging (MRI) may be preferred or obtained in addition to CT. Positron
emission tomography (PET) and PET-CT may be used to look for distant metastases and second primary
cancers. A metastatic workup should include a chest X-ray for early-stage/low-risk lesions or a chest CT
or PET scan in advanced-stage cancers, as well as liver function tests.
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Staging
In broad terms, small tumors without obvious nodal metastases represent early stage I and II cancers,
whereas larger, more extensive tumors and/or the presence of cervical nodal metastases represent
advanced stage III and IV cancers. Factors that have been linked to poorer outcomes include advanced-
tumor stage, increased soft-tissue depth of invasion, presence of nodal metastases, perineural invasion,
lymphovascular invasion, and extranodal extension (ENE). 4 These factors are used to guide treatment
and provide patients with prognostic information. As a general rule, the presence of nodal metastases
reduces survival by 50%, except in HPV-associated (p16-positive) oropharyngeal cancer. 10
The TNM classification, based on the extent of the tumor (T), spread to the lymph nodes (N), and the
presence of metastasis (M), is used to communicate information about tumor size and spread as well as
provide prognostic data. At the time of this writing, the eighth edition of the American Joint Committee
on Cancer (AJCC)/International Union Against Cancer (UICC) staging system has replaced the seventh
edition. 11 For oral cavity cancers, the depth of invasion is now incorporated into the T classification
because of the negative effect this parameter has on prognosis. Similarly, ENE has a profound adverse
effect on the prognosis and is now part of the N classification. Another major difference is the division of
oropharyngeal cancer classifications based on HPV positivity, because HPV-associated oropharyngeal
cancer is markedly different in prognosis and behavior from non-HPV–associated cancer. Staging based
on clinical and pathologic information is denoted by a “c” or “p” because surgical pathologic data, such
as the number of involved lymph nodes or microscopic ENE, provide greater detail regarding adverse
features with significant prognostic impact.
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Sites
Oral Cavity Cancer
The oral cavity is the most common site for SCC of the head and neck (Figure 37.2). Most oral cavity
cancers are treated surgically with the goal of achieving clear 1 to 2 cm margins. 10 Neck dissection is
performed when lymph node metastases are detected or when there is elevated risk of occult lymph node
metastases, and there is growing evidence to support sentinel lymph node biopsy for oral cavity
malignancies. 12 Radiation can be used as definitive treatment; however, it is not routinely used because
of the elevated rates of osteoradionecrosis associated with the higher therapeutic doses required for
definitive versus adjuvant treatment. Advanced-stage cancer is usually treated with surgery and adjuvant
radiation or combined chemotherapy and radiation when there are adverse findings (e.g., positive
margins, locally advanced disease, perineural or lymphovascular invasion, N2 or N3 nodal disease, and
ENE). 13–16 Most surgery is performed transorally, except for very posterior lesions, which may require a
mandibulotomy or a transcervical approach.
FIGURE 37.2 Cancer of the oral tongue seen on the right lateral tongue.
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Oropharyngeal Cancer
Oropharyngeal cancer is distinctly different from oral cavity cancer, although here too SCC
predominates, accounting for approximately 90% of cases. 5,7,17 The tonsillar region and base of tongue are
the most common sites for oropharyngeal cancer, and specimens should be tested for p16 protein or HPV
DNA or RNA for staging. 17
Compared with treatment of oral cavity SCC, management of oropharyngeal SCC is more controversial.
For early stage cancers, surgery alone or radiation alone results in comparable overall survival. Radiation
has been favored at many centers to preserve speech and swallowing function. 18 However, transoral laser
microsurgery (TLM) and transoral robotic surgery (TORS) have emerged as alternatives with improved
functional outcomes over traditional open techniques. 19 For advanced cancers, current evidence supports
the use of either combined chemotherapy and radiation therapy or surgery. 18 If surgery is performed, it
may be followed by adjuvant therapy depending on the pathologic findings and stage.
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Nasopharyngeal Cancer
The World Health Organization (WHO) classifies NPC into three subtypes 20 :
Type I: Keratinizing squamous cell carcinoma
Type II: Nonkeratinizing squamous cell carcinoma
Type III: Undifferentiated carcinoma
It is type III that accounts for over 95% of nasopharyngeal carcinomas in high-incidence areas, specifically
southern China and Southeast Asia, with a strong association with EBV. 20 Presenting symptoms are often
confused with benign and infectious processes, potentially leading to late diagnosis, and include a neck
mass from nodal metastasis, middle ear effusion with hearing loss (from Eustachian tube obstruction),
nasal obstruction, and sore throat. Flexible fiberoptic nasopharyngoscopy is performed to visualize the
nasopharynx in patients suspected of NPC.
NPC is a radiosensitive malignancy, and radiation therapy to the primary and to the neck with or without
concurrent chemotherapy is the mainstay of treatment for all types of NPC. 20,21 Neck dissection is
performed for residual neck disease or resectable regional recurrence. Surgery with or without
reirradiation is performed for resectable local recurrences. 20 Surgery of nasopharyngeal tumors can be
complex because of limited access and perilous because of risk to the optic nerves as well as the internal
carotid artery and cavernous sinus. Targeted treatment for NPC with monoclonal antibodies such as
cetuximab, pembrolizumab, and nivolumab is being actively investigated. 20,21
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Hypopharyngeal Cancer
Hypopharyngeal and laryngeal cancers are often contiguous with each other as well as with the cervical
esophagus. Additionally, many of these tumors are multicentric. Early stage hypopharyngeal cancers can
be treated by surgery alone or radiation alone with comparable 5-year survival and local disease control. 4
Surgical approaches are most commonly transoral for early stage cancers, including robotic and laser
resections, and transcervical for late stage cancers. 22 Advanced-stage piriform sinus cancers usually
require a total laryngectomy and pharyngectomy (Figure 37.3). Advanced-stage cancers are given
postoperative radiation. Alternately, they may be treated with combined chemotherapy and radiation
with surgery reserved for salvage of residual or recurrent disease. As with laryngeal cancer, organ
preservation (i.e., larynx preserving) protocols (induction chemotherapy followed by radiation with
surgery reserved for salvage or concurrent chemoradiation therapy) have shown equivalent overall
survival to the traditional approach of surgery and adjuvant radiation; therefore, many centers favor
chemoradiation as the initial treatment for most hypopharyngeal cancers, although the prognosis for
hypopharynx cancer remains grim.
22 The prevalence of neck metastases on presentation of
hypopharyngeal cancers is 65% to 80%, and hypopharyngeal cancer is associated with the worst
prognosis of all UADT SCCs, with an overall 5-year survival of around 35%. 21
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FIGURE 37.3 Laryngopharyngectomy specimen from a patient with hypopharyngeal cancer.
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Laryngeal Cancer
Most laryngeal cancers occur in the glottis (64%), followed by the supraglottis (34%), and only rarely in
the subglottis (2%). 4 Only about 5% of laryngeal SCCs occur in nonsmokers and nondrinkers. 4 HPV has
been reported to be associated with laryngeal cancer but with much less frequency than in oropharyngeal
SCC. The incidence and pattern of nodal spread varies with the location of the primary tumor. Lymphatic
drainage of the glottis is sparse, and early stage primary cancers rarely spread to the lymph nodes. Also,
because hoarseness is an early symptom, most glottic cancers are diagnosed at an early stage. Thus,
cancer of the glottic larynx has an excellent average cure rate of 80% to 90%. 4
TLM and TORS can be used for early stage glottic and supraglottic tumors if adequate visualization of the
tumor can be achieved. Early stage glottic tumors are frequently treated with TLM or open cordectomy. If
there is extension to the arytenoids, then a hemilaryngectomy can be performed. Such surgeries are
aimed at preserving the laryngeal functions of phonation and airway protection.
Advanced laryngeal cancers are treated with total laryngectomy or combined chemotherapy and
radiation therapy. Chemoradiation is usually the preferred initial treatment modality based on the results
of the landmark Veterans Administration Laryngeal Cancer Study and subsequent RTOG 91-11 study,
which showed comparable survival for patients treated with total laryngectomy versus an organ
preservation protocol with surgical salvage. In this study, the laryngeal preservation rate was 67%. 23,24
Subsequent studies have confirmed these findings and have established concurrent chemotherapy with
cisplatin and radiation therapy as the standard of care. 25–27 Bulky T4 cancers with either thyroid cartilage
penetration or ≥1 cm base of tongue extension are an exception and should be treated with surgery. Also,
patients with laryngeal dysfunction prior to treatment should not undergo organ preservation treatments
because laryngeal preservation is valuable only if the core functions of breathing, speech, and airway
protection during swallowing are preserved. 27
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Unknown Primary Cancer
Neck metastases without a primary tumor that can be localized by physical examination or radiographic
imaging are known as unknown primary or occult primary cancers. Unknown primary cancers account
for 1% to 4% of head and cancers. 28 A painless neck mass in an adult should be considered a malignancy
until proven otherwise. Fine-needle aspiration (FNA) is used to confirm the diagnosis. Metastatic UADT
SCC is the most common cancer presenting as an unknown primary neck mass, followed by papillary
thyroid cancer and cutaneous SCC. 28 The oropharynx is most frequently the origin of cancer in patients
presenting with a cervical metastasis and an unknown primary. HPV detected in FNA specimens
suggests an oropharyngeal primary, most commonly arising from either the tonsil or base of tongue.
Further workup consists of imaging with CT or MRI and panendoscopy with directed biopsies, usually
including the nasopharynx, both sides of the base of tongue (including potential lingual tonsillectomy),
bilateral tonsillectomies, and both piriform sinuses, although biopsy sites may be selected based on the
level(s) of neck disease and can vary slightly from institution to institution. 28,29
When the primary remains unknown despite complete workup, most patients are treated with
multimodality therapy, either resection (neck dissection) followed by adjuvant radiation with or without
chemotherapy, or primary chemoradiation with or without posttherapeutic neck dissection. Radiation is
usually given to both sides of the neck and to the nasopharynx, oropharynx, and hypopharynx/larynx.
An exception is early stage cancers (T0N1 and HPV-associated T0N2a without other risk factors), which
are usually treated with a single modality consisting of either surgery alone or radiation alone. 28
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Treatment
In general, early-stage tumors are treated with single modality therapy and late-stage tumors are treated
with multimodality therapy, usually surgery followed by adjuvant radiation with or without
chemotherapy with the exceptions noted earlier.
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