Trauma, 7th Ed.

CHAPTER 21. Face

Robert M. Kellman

INTRODUCTION

Facial structures participate in essential functions of human life, including respiration, mastication, deglutition, vision, and the expression of both verbal and nonverbal communication. The face is the focal point of human social interaction.1 Thus, to restore facial form and function is to restore much of a patient’s opportunity to live a normal life.

In order to effectively manage facial trauma, the surgeon must understand care in the emergency room; the anatomy, evaluation, and management of injuries to the soft tissue, visceral, and bony components of the face; and the management of secondary deformities and complications. In this manner, not only is a broad discussion of facial trauma achieved, but the reader is also made aware of the place occupied by facial trauma within advanced trauma life support (ATLS) (see Chapter 10) and subsequent management.

EMERGENCY DEPARTMENT CARE

image Primary Survey of the Face

Care of facial trauma in the emergent setting, as in the management of any trauma, is initially focused on the “ABCs.” The adequacy of airway, breathing, and circulation are determined, and the appropriate ATLS algorithms are instituted. In addition to airway and circulation or bleeding issues, the cervical spine must be appropriately managed, and it adds potential difficulty to management of the airway.

Airway

Injuries to the upper aerodigestive tract and craniofacial skeleton may result in airway obstruction from tissue trauma and edema, foreign debris, or bleeding. The natural mechanisms of airway protection rely on functioning oropharyngeal structures supported by an intact facial skeleton. Injuries may lead to retrodisplacement of these structures, which may cause compromise of the airway. Trauma to the airway itself or neurologic injury can cause direct airway obstruction or loss of vocal cord function.

Airway compromise may be rapidly lethal and is assessed first. The reader is cautioned that significant obstruction of the airway, even impending loss of the airway, may be accompanied by normal or near-normal oximetry. The Glasgow Coma Scale (GCS) is used to rapidly assess for neurologic impairment that may lead to centrally based loss of airway protection. Subcutaneous emphysema may suggest pharyngeal, laryngeal, or tracheal disruption. Stridor (the sound of breathing through a partially obstructed airway) suggests airway narrowing and possible impending obstruction. If time permits, flexible fiberoptic nasopharyngolaryngoscopy allows rapid and definitive evaluation of the potentially compromised hypopharyngeal and laryngeal airway.

Foreign material in the airway may be manually evacuated, and blood and secretions are suctioned from the oral cavity and pharynx. A “jaw thrust,” even in the setting of mandibular trauma, and bag-valve mask (BVM) assistance may allow oxygenation, especially in the setting of injury to the brain or spinal cord. The compromised airway can then be secured via rapid sequence orotracheal or nasotracheal intubation. Orotracheal intubation is preferred in the setting of possible midface fractures, though nasal intubation can be accomplished with care and a thorough knowledge of the anatomy of the nose and skull base anatomy.24 If necessary, the airway should be accessed through an emergent tracheotomy or cricothyrotomy.

Bleeding

After management of the airway, any brisk bleeding should be controlled. The face is very well vascularized, and soft tissue injuries may result in profuse hemorrhage. The scalp bleeds profusely because large vessels are located near the surface and the tissue is relatively inelastic.5 Intraoral and pharyngeal bleeding may be due to injury to the carotid artery or internal jugular vein or their branches and may result in compromise of the airway. After securing the airway, the throat may be packed in order to control pharyngeal bleeding, the source of which may be difficult to determine initially. Injuries to the carotid artery and/or jugular vein may also occur with coincident trauma to the neck. A neck hematoma may threaten the airway via extrinsic compression. Bullet wounds involving the parapharyngeal and retropharyngeal spaces, the nasopharynx, and the infratemporal fossa carry the risk of injury to the internal carotid artery, and emergent angiography may be indicated. Massive, high-energy wounds to the face may present with massive bleeding. Direct pressure and pressure dressings are applied. A pressure dressing secured to the face with a clear synthetic full-face wrap after airway diversion through a tracheostomy or cricothyrotomy has been described.24

Cervical Spine

Facial injuries may also be associated with trauma to the cervical spine and brain. In order to minimize further damage, any patient with suspected injury to the cervical spine should be immobilized on a backboard with a rigid cervical collar until definitive evaluation can be completed.2 Most notably, cervical spine precautions are maintained during intubation or emergent tracheostomy by maintaining a neutral position of the head via inline traction and minimal extension. Various techniques are available to make intubation safer and more dependable.3,4

Disability

Finally, assessment of the patient’s level of consciousness and neurologic function is summarized by the Glasgow Coma Scale score (GCS). Up to 15 points are allocated based on a patient’s motor, verbal, and eye-opening performance. Computed tomography (CT) scan of the head and brain and neurosurgical consultation are indicated with a GCS <14.2

image Secondary Survey

With the airway, breathing, hemodynamics, and cervical spine stabilized, the remainder of the trauma survey is undertaken. At this time, facial and craniomaxillofacial injuries are also identified. The need for imaging should be determined, since radiographic studies are often readily available in the emergency department. With new fast CT scanners in use, the maxillofacial structures can be included in the initial screening scans. If the patient is stable, the input of consultants who care for craniofacial and associated wounds is sought. This may include otolaryngology/facial plastic surgery, plastic surgery, oral and maxillofacial surgery, ophthalmology, and neurosurgery.

NORMAL ANATOMY

In order to make an accurate assessment of craniofacial injuries and to effect an adequate reconstruction, an understanding of the normal anatomy is required.

image Soft Tissue

The scalp covers the entire cranial vault and extends over the upper face. It consists of five layers including skin, subcutaneous fat, galea aponeurosis (including the frontalis muscle in the forehead), loose areolar tissue, and periosteum of the skull known as the pericranium. In the inferior aspect of the temporal scalp, the temporal branch of the facial nerve runs over the superficial surface of the temporalis investing fascia to innervate the frontalis muscle (Fig. 21-1). The supratrochlear and supraorbital neurovascular bundles emanate from notches or foramina in the superior orbital rims and penetrate the frontalis muscle 2–4 cm above the rim. Therefore, subperiosteal dissection of the 3–4 cm above the supraorbital rims ensures protection of these structures until they are encountered at the orbital rim itself.

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FIGURE 21-1 The fascial planes of the temporal scalp and underlying temporalis muscle. The frontal branch of the facial nerve located on or within the superficial layer of deep temporalis fascia. (Reproduced with permission from Kellman RM, Marentette LJ. Atlas of Craniomaxillofacial Fixation. Raven Press: New York; 1995:97.)

The eyelid is a trilamellar structure (Fig. 21-2). The anterior lamella consists of skin and the sphincteric orbicularis muscle and the posterior lamella consists of the conjunctiva. The tarsal plates comprise the middle layer, and they are attached at their transverse extents to the medial and lateral orbital rims by the medial and lateral canthal tendons, respectively. The orbital septum extends from the tarsus to the orbital rim and separates the orbicularis from the orbital fat. Levator and depressor muscles insert on the superior and inferior margins of the upper and lower lid tarsal plates, respectively, and open the eyelids upon stimulation by the third cranial nerve. The orbicularis closes the lids and is innervated by the facial nerve. The conjunctiva, or posterior lamella, covers the inner surface of the lid and extends over the anterior aspect of the globe itself.

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FIGURE 21-2 Cross section of eyelids and schematized globe. (Reproduced with permission from Wobig J. Eyelid Anatomy. In: Putterman AM, ed. Cosmetic Oculoplastic Surgery. 2nd ed. Philadelphia: WB Saunders; 1993:73. © Elsevier.)

The medial canthal tendon (MCT) is derived from the orbicularis oculi muscle, which divides into anterior and posterior slips (Fig. 21-3). These fuse, forming the common anterior and posterior limbs of the MCT, which inserts on the anterior and posterior lacrimal crests, respectively. A third slip of the tendon also attaches more superiorly. Together, these structures surround the lacrimal sac within the lacrimal fossa. Tears enter the lacrimal canaliculi through the puncti of the upper and lower lids and flow into the lacrimal sac. With blinking, the components of the MCT squeeze the sac and force tears into the nasolacrimal duct.

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FIGURE 21-3 The components of the medial canthal tendon are represented by arrows. The resultant vector is best reconstructed by placing the tendon or a canthopexy stitch in a posterior–superior position, at the point X. (Reproduced with permission from Rodriguez L, Zide B. Reconstruction of the Medial Canthus. Clin Plastic Surg. 1988;15:257. © Elsevier.)

The lateral canthal tendon inserts on Whitnall’s tubercle, which is located 2-mm posterior to the lateral orbital rim and 9-mm inferior to the zygomaticofrontal (ZF) suture.

The external ear projects 15–25° from the parasagittal plane. The cartilaginous framework defines ridges and hollows covered by perichondrium and skin with no subcutaneous fat. It has a complex anatomical structure and can be challenging to reconstruct.

The nose consists of nine aesthetic subunits and comprises a bony and cartilaginous framework with an overlying skin–soft tissue envelope. These subunits include the midline dorsum, paired sidewalls, the midline tip, and columella, as well as the paired lateral sidewalls, soft triangles or facets, and alae. The lower third is analogous to a tripod consisting of the septum and the paired lower lateral cartilages.6

Like the eyelids, the lips consist of a sphincteric muscle, the orbicularis oris, levator and depressor muscles, and tendonous support in the form of the modiolus. Loss of muscular attachment to the modiolus may result in rounding of the commissure and oral incompetence. The lip margins consist of vermillion, a thin nonkeratinizing squamous epithelium overlying rich capillary beds. The junction of the vermillion and lip skin is called the white roll, and the junction of vermillion and mucosa is known as the wet line. The philtrum is found in the central aspect of the upper lip, extending vertically from the columella to the vermillion.

The cheeks comprise the lateral aspect of the face. The key aesthetic point of the cheek is the malar prominence. Most of the muscles of facial expression lie within a fibrofatty fascial layer of the cheek known as the superficial muscular aponeurotic system.

image Visceral

The deep aspect of the cheek contains the parotid gland and facial nerve. The parotid duct crosses the lateral surface of the masseter and enters the mouth through an orifice in the buccal mucosa lateral to the second maxillary molar. The duct is intimately associated with the buccal branches of the facial nerve.

The facial nerve exits the stylomastoid foramen of the temporal bone and immediately enters the posterior aspect of the parotid gland. The nerve divides into a superior and inferior divisions and then ramifies further creating five divisions as follows: the frontal, the zygomatic, the buccal, the marginal mandibular, and the cervical. The frontal branch crosses the midpoint of the zygomatic arch. The zygomatic branch travels inferior to the zygomatic arch until it inserts on the deep surface of the orbicularis oculi. The buccal division consists of multiple anastomotic branches that course over the masseter muscle to innervate the buccinator and upper lip and nasal muscles. The marginal mandibular branch innervates the depressor anguli oris and lower aspect of the orbicularis. The cervical branch innervates the platysma muscle.

Sensory innervation of the face is supplied primarily by the divisions of the fifth cranial nerve, though the great auricular nerve contributes some as well.

The contents of the orbit include the globe, the extraocular muscles, the terminal branches of the second, third, fourth, and sixth cranial nerves, as well as terminal branches of the internal carotid arterial system.

image Bony

The upper face (the forehead) is supported by the paired, broad, flat frontal bones that articulate inferiorly with the nasal bone and frontal process of the maxilla medially and with the frontal process of the zygoma laterally. Posterior to the lateral orbital rims, the frontal bone articulates with the greater wing of the sphenoid. Inferiorly, the frontal sinus communicates with the nasal passage through the paired nasofrontal ducts (NFDs) that penetrate the sinus floor medially.

The midface includes the paired maxillae, zygomas, and nasal bones. It articulates deeply with the orbital walls and ethmoid structures. Thickened regions of these structures comprise the medial, lateral, and posterior “vertical buttresses” as well as the “horizontal beams”—lines of thickened cortical bone that withstand greater loads than the intervening regions of thin, weak bone (Fig. 21-4). This lattice-like arrangement of the midface is suspended from the orbital bar and is projected from the skull base via its articulations with the ethmoid, pterygoid, and temporal bones. The vertical buttresses resist the forces of mastication and include the paired nasomaxillary (medial), zygomaticomaxillary (ZM) (lateral), and pterygomaxillary (posterior) struts. The ZM extends from the maxillary alveolus above the first molar, across the ZM suture and the ZF suture in the lateral orbital rim to the suprorbital bar. The nasomaxillary buttress ascends from the canine fossa into the lateral wall of the piriform aperture and superiorly along the nasomaxillary junction to the glabella. The pterygomaxillary buttress comprises thickened bone at the junction of the posterior maxillary sinus and the takeoff of the pterygoid plates.7

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FIGURE 21-4 (A) Classic medial (1), lateral (2), and posterior (3) vertical maxillary buttresses and the infraorbital horizontal buttress. (B) Lines of the classic Le Fort fractures of the midface. (C) Comminuted midface fractures, including right Le Fort III, bilateral Le Fort II, and left Le Fort I fractures as well as frontal sinus, orbital, and palatal fractures, demonstrating the complex pathology commonly resulting from high-speed blunt force trauma. (A) (Reproduced with permission from Forrest CR, Phillips JH, Prein J. Craniofacial Fractures, Le Fort I-III Fractures. In: Prein J, ed. Manual of Internal Fixation in the Cranio-Facial Skeleton. Berlin Heidelberg: Springer-Verlag; 1998:109.) (B) (Reproduced with permission from Ducic Y, Hamlar DD. Fractures of the Midface. Facial Plast Surg Clin North Am. 1998;6:471. © Elsevier.)

The horizontal stabilizers are less robust and include the maxillary alveolar bone, the infraorbital rims, and the supraorbital rims (frontal bone). In addition, the orientation of medial and lateral pterygoid plates provides horizontal stabilization for the posterior buttress. In the anterior/posterior (AP) direction, the zygomatic arches determine the AP position of the midface.7

The lateral orbital wall consists of the greater wing of the sphenoid and the zygoma anteriorly. The orbital floor is predominately formed by the orbital plate of the maxilla, and the zygoma makes a contribution laterally. Vertical processes of the palatine bones also contribute to the medial orbital walls. Posteriorly, the orbital plate of the maxilla sweeps medially and superiorly to meet the lamina papyracea. The orbital roof and floor are mostly concave anteriorly, but the floor is convex anteromedially. Thus, an anteromedial fracture that eliminates this convexity will significantly enlarge the orbital volume and result in enophthalmos.

The zygoma is the keystone structure of the midfacial buttress system. The infraorbital rim and lateral buttress intersect in the body of the zygoma. Thus, the zygoma and maxilla in this region are considered together as a zygomaticomaxillary complex (ZMC) (Fig. 21-5).

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FIGURE 21-5 (A) The vertical and horizontal arcs created by the zygomaticomaxillary (ZMC) complex. (B) Axial computed tomography image of left ZMC fracture demonstrates loss of malar projection. (C) Schematic illustration of use of the bone hook to mobilize the ZMC complex. (A) (Reproduced with permission from Stanley R. The zygomatic arch as a guide to reconstruction of comminuted malar fractures. Arch Otolaryngol: Head Neck Surg. 1989;115:1459. Copyright © 1989 American Medical Association. All rights reserved.) (C) (Reproduced with permission from Markowitz BL, Manson PN. Craniofacial Fractures, Zygomatic Complex Fractures. In: Prein J, ed. Manual of Internal Fixation in the Cranio-Facial Skeleton. Berlin: Springer-Verlag; 1998:133.)

The mandible is the primary component of the lower third of the face. The mandibular alveolus is the arch of tooth-bearing bone that extends anteriorly from the angle. As might be expected, the bone is thickest in the tooth-bearing areas. The vertical rami extend from the angles to the temporal bones at the temporomandibular joint. The inferior alveolar nerve enters the lingual side of the ramus and runs through the mandibular body to exit as the mental nerve.

EVALUATION

image Soft Tissue

Soft tissue injuries are generally obvious on initial physical examination; however, all soft tissue wounds must be accurately evaluated and documented. After adequate local anesthesia, wounds should be carefully probed and examined to determine depth, extent and involvement of visceral structures.

The severity of the injury depends upon the amount of energy transferred to the wound. Close-range ballistic wounds may cause severe tissue damage, and they can be classified according to the region of tissue loss. Shotgun wounds are commonly inflicted from close range and impart energy to an even wider field of tissue. Suicide attempts represent the most common shotgun wounds, and these usually direct energy to the lower face and midface from below.8

Skin does not respond to blunt trauma randomly. Lee et al.9 determined that blunt trauma results in repeatable patterns of soft tissue wounding. In a study of blunt wounds to cadaver heads, they found that in approximately 80% of wounds the skin broke along cleavage planes as previously defined by others. These cleavage planes resemble the relaxed skin tension lines along which wrinkles occur.

image Visceral

High-energy cause, deep soft tissue wounds, craniofacial fractures, and multiorgan trauma suggest the possibility of an intracranial injury. The neurologic examination should be repeated, and a head CT should be obtained routinely. Ophthalmologic examination should be performed and repeated, and injury to the lacrimal drainage system must be considered. The loss of facial sensation may suggest the depth or extent of injury. Facial paralysis must be identified, since primary facial nerve anastamosis should be attempted during primary repair of a facial wound. Wounds to the cheek or submental region that injure the salivary glands or ducts should be identified.

image Bony

Most often, craniofacial fractures occur along well-recognized lines of weakness in the midfacial skeleton and in repeated patterns in the mandible. Clinical evaluation is directed by knowledge of these typical fractures.

Upper Face

A laceration of the forehead skin and depression of the forehead suggest a possible fracture of the frontal sinus. The presence of an anterior table fracture associated with mental status changes or cerebrospinal fluid (CSF) rhinorrhea should alert the surgeon to possible posterior table involvement, a dural tear, or a traumatic brain injury.

Midface

The lattice system of medial and lateral buttresses usually prevents random fractures through the midface.10 Instead, the midface most commonly fractures along the classic weak lines described by Rene Le Fort in 1901, although variations in the pattern and in the combination of Le Fort fractures are the rule11 (Fig. 21-4). A Le Fort I fracture separates the maxillary alveolus and palate from the upper midface. Horizontal impact of the upper midface usually results in Le Fort II fracture line, which crosses from the nasal dorsum, ascending process of the maxillae, and lacrimal bones into the orbit. In the orbit, the fracture line descends through the floor and infraorbital rim into the anterior and lateral antral walls, and through the pterygoid plates. This separates a pyramidal central midfacial and alveolar segment from the zygomas and pterygoid plates. In contrast, downward, oblique impact separates the facial skeleton from the skull base (“craniofacial disjunction”) via fractures across the nasofrontal suture, the lacrimal and ethmoid bones, and into the orbital floor. At the inferior orbital groove, the fracture trifurcates, extending across the ZF suture, the zygomatic arch, and the pterygoid plates.

Clinical examination of the vertical and horizontal buttresses involves inspection and palpation. Mobility of the midface relative to the skull base suggests a Le Fort fracture. Palatal fractures in the sagittal plane are suggested by palatal lacerations, widening of the dental arch, and abrupt changes in the vertical level of dentition. Step-off deformities of the infraorbital rims may be palpated. The upper midface fractures classically cause the face to recede posteroinferiorly, creating a flat or “dish-face” appearance. This commonly results in early posterior contact and anterior open-bite.

The zygomatic fracture typically results in loss of the anterior, lateral, and vertical position of the malar eminence. Despite varying degrees of edema, malar flattening is evident from the vertex or basal perspective.

Fractures of the weak, central compartment of the midface result in characteristic naso-orbital ethmoid (NOE) injuries. The sine qua non of the NOE fracture is telecanthus. Disruption of the bony attachment of the medial canthi can be determined through inspection and palpation. The nasal root will appear broad and flat, and the canthus will appear rounded and lateralized, and it may be displaced inferiorly. The central bony fragments may be easily mobilized, and the canthal tendons may give easily with gentle lateral tugging. The canthi should be no further apart than the alar base of the nose and should be roughly one half of the interpupillary distance. In general, an intercanthal distance of greater than 35 mm is suggestive of telecanthus, and greater than 45 mm is usually definitive.12

Orbit

Isolated orbital blowout fractures (fractures of the orbital walls without associated fractures through the orbital rims) occur when blunt force is applied directly to the orbital contents and transmitted to the walls. Intraorbital volume is increased and the globe recedes posteriorly (known as “enophthalmos”). Diplopia is readily recognized by the patient. Enophthalmos is often evident on the basal or vertex view of the patient, although orbital and periorbital edema may fill the enlarged orbital volume, temporarily preventing recession of the globe. Orbital wall fractures may also result in herniation and entrapment, most commonly of the inferior or medial rectus muscles, restricting extraocular movements (Fig. 21-6). Chemosis, scleral injection, periorbital ecchymosis, and diplopia suggest orbital fractures.

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FIGURE 21-6 Coronal computed tomography image of orbital blowout fracture with disruption of the orbital floor and medial orbital wall. Entrapment of the medial rectus muscle is also seen.

Mandible

Clinical evaluation can be directed by knowledge of the mechanism of injury. In addition, gingival lacerations, ecchymoses, and bleeding are signs of underlying fracture. Malocclusion, facial asymmetry, stepoff deformities of the dental arch, mobility of the arch with palpation (performed gently), pain, and trismus (restricted mandibular movement) are obvious indications for radiographic imaging.

Radiographic Evaluation

CT scanning has essentially replaced plain film radiography for evaluation of craniofacial fractures. Studies have shown that CT evaluation of the mandible will reveal fractures not visible on plain and panoramic radiographs, though orthopantomograms are still helpful for following mandible fractures.13 Perhaps the most significant advancement in imaging is the three-dimensional (3D) reconstruction of axial CT sections (Fig. 21-7). Three-dimensional CT images can be rotated 180 or 360° on a variable axis and clearly reveal fracture lines as well as the relations of small bony fragments. With multiple complex fractures, 3D images facilitate surgical planning; however, it must be kept in mind that the computer algorithms that create the 3D images do create some inaccuracies, so that careful analysis of directly obtained CT images remains essential.14

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FIGURE 21-7 (A) Three-dimensional computed tomography scan of the mandible demonstrates the ease with which the special orientation of the segments of this subcondylar and ramus fracture are visualized. (B) Three-dimensional computed tomography scan of the same patient with mandible in situ. Evident are the cross bite and anterior open bite as well the facial asymmetry that results from vertical shortening of the left ramus.

MANAGEMENT

image Soft Tissue

Low-energy Wounds

Careful written and photographic documentation of injuries and their repair may be useful in counseling patients and in interacting with the legal system, which may be necessary. Most soft tissue wounds are then managed at the bedside using local anesthesia.

After local anesthesia is achieved, wounds are debrided and cleansed. Contamination and foreign material are sources of deep tissue infection, and granules of foreign material embedded in the skin can cause permanent tattooing. Copious saline irrigation is commonly performed, although one group found that irrigation does not significantly reduce the risk of infection or improve the cosmetic outcome in facial wounds that are superficial, minimally contaminated, and less than 6 hours old.15 They suggest that irrigation may damage tissue and that such wounds are amenable to cleansing with saline and gauze.

Debridement is limited to frankly necrotic soft tissue. Given the abundant vascularity of the face, tissue that appears compromised, but not necrotic, is likely to survive.

The following general principles may then be applied to the closure of soft tissue wounds of the face. First, with adequate debridement and irrigation, the robust vascularity of the face supports primary closure of almost all facial wounds. With proper antimicrobial therapy, the incidence of secondary infection is low, even in the setting of bite wounds less than 24 hours old. Closure of facial wounds by secondary intention typically results in unacceptable scars. Second, wounds should be closed in a layered fashion. Mucosa is closed with interrupted absorbable sutures, whereas muscle should be reapproximated with braided, absorbable suture. Failure to reapproximate muscular layers can result in loss of function and facial deformity, as well as depressed and excessively wide scars. Skin closure is accomplished with interrupted absorbable polyglycan 4-0 dermal stitches (except in the thin skin of the nose, eyelids, and ear) followed by 5-0, or 6-0 monofilament sutures in the epidermis. In small children, where suture removal presents an additional challenge, 6-0 fast absorbing gut may be used. Every attempt is made to achieve eversion of wound edges. Where tissue is lost via avulsion, undermining the skin up to 2–4 cm from the wound edge will often allow primary closure. Undermining is usually accomplished in the subcutaneous plane, although the forehead and scalp are undermined in the subgaleal plane, and nasal skin is undermined in the submuscular plane. In larger avulsions, local or regional flaps may be needed. Alternatively, a skin graft can be used in the acute setting, and definitive closure can be achieved in the future when the full range of reconstructive techniques may be more available. Facial sutures should be removed early, often at 4–5 days and certainly within 1 week, in order to prevent “railroad track” scars.

Lips

The mucosa, the orbicularis, and the skin are closed in discrete layers. The primary aim is reapproximation of the white roll and the vermillion margin, as well as the wet line and the orbicularis. Great care is taken to precisely reapproximate the vermillion-cutaneous junction, and the authors commonly begin lip closures with a single interrupted skin suture at the vermillion-cutaneous border followed by a muscular stitch that also contributes to precise alignment. Next, the mucosa is closed with interrupted absorbable sutures. The remainder of the muscle and skin is then closed.

Multiple algorithms exist for the reconstruction of full-thickness lip defects, and these are handled in the same fashion as lip reconstruction after tumor resection.16

Eyelids

Similar to lip repair, eyelid closure involves layered closure of the lamellae, as well as careful reconstruction of the lateral supporting structures, in this case the canthal tendons. The tarsus is reapproximated with interrupted absorbable 6-0 stitches; however, the levator aponeurosis must be repaired to prevent lid ptosis. The grey line is reapproximated with 6-0 silk suture. The conjunctiva may be closed with interrupted, absorbable sutures, though it is not always necessary. Finally, the skin and orbicularis may be closed as a single flap.

The canthal tendons must be repaired if torn or if displaced from the orbital rims. There is a common misconception that the lateral canthus attaches more superiorly than the medial canthus; however, recent analyses have revealed that these attachments are actually along a horizontal line.17 Repair of the MCT is covered below in a discussion of nasal orbital ethmoid complex fractures. The medial canthal ligament is repaired by fixing it to the lacrimal bone, usually with a transnasal suture or wire.

Nose

The principles of augmentive rhinoplasty and of nasal reconstruction of skin cancer defects are utilized in repairing soft tissue trauma of the nose. Superficial lacerations can often be closed primarily. The relatively inelastic nasal skin is, however, prone to scar contracture, trapdoor deformity, and scar depression. Therefore, wound edges are everted via submuscular undermining, deep sutures are used to reapproximate wound margins, and skin closure is with vertical mattress sutures. Small areas (<1 cm) of skin loss located in concavities of the nasal surface (such as the nasofacial or alar facial sulci) can be left to granulate, as these tend to heal nicely by secondary intention.18 Lacerated cartilages should be reapproximated with interrupted 4-0 polydioxanone sutures. The alar rims, especially in the soft triangles, are especially prone to notching as a result of scar contracture. Here, eversion of wound edges is essential, and skin is supported with underlying cartilage batten grafts harvested from the septum or auricular conchae.

For extensive tissue loss, the principles of cancer reconstruction are applied. These involve reconstruction of all affected layers, including mucosa, cartilage framework and skin, utilizing a variety of available grafts or flaps, including free tissue transfer when indicated.18

The septum must be examined. Hematomas must be aspirated or drained via incision and drainage to prevent cartilage loss and resultant late saddle nose deformity. A quilting stitch or a nasal pack is placed in order to coapt the cartilage and mucoperichondrium to prevent reaccumulation.

Ear

As with the nose, ear skin is inelastic and supported by a cartilaginous framework. Lacerations of skin and cartilage must be meticulously repaired. Auricular cartilage is directly repaired and/or the anterior and posterior perichondrium are reapproximated, and, where the cartilaginous support is absent, supporting cartilaginous grafts may be introduced and wound edges everted in order to prevent notching. Analogous to the septal hematoma, an auricular hematoma separates the skin from the underlying cartilage and must be evacuated. A hematoma may be removed through needle aspiration or a small stab incision, and a bolster is then sewn to the ear.

Significant tissue loss requires grafting of cartilage, often taken from the contralateral concha, and soft tissue coverage. For large defects, pedicled, staged soft tissue flaps provide coverage. Postauricular skin flaps cover the helix and antihelix well, and the temporoparietal fascial flap covered by a skin graft is useful for larger defects.

For complete or near-complete avulsion, primary reattachment of the auricle, two-stage postauricular skin flap coverage of the auricle, and microvascular reanastomosis may be used, though simply sewing the avulsed segment into place is unlikely to succeed. In this case, the cartilage may be denuded of all skin and perichondrium and buried in a subcutaneous pocket for later reconstruction. Complete reconstruction using carved rib cartilage may be used as well.

image Visceral

Injuries to the cheek involving deep tissue must be explored for possible trauma to the parotid gland and duct. Laceration of the gland itself is often not reparable, although an attempt at closure of the parotidomasseteric fascia may be made. Injury to the parotid gland may result in a salivary-cutaneous fistula or sialocele.

It is important to assess for a possible injury to Stensen’s duct. Treatment options for ductal injuries include primary anastomosis, creation of an oral fistula, ductal ligation, and conservative nonoperative measures. Repair requires cannulation and microsurgical anastomosis. Some authors favor conservative management.19,20 When the duct is not repaired, antisialogogues are useful to reduce salivary output and pain.21

Salivary cutaneous fistula and sialoceles may result from injury to the gland, an unrecognized ductal laceration, or intentionally conservative management of parotid injury. Sialoceles should be aspirated in serial fashion, and a pressure dressing may be applied. Most will resolve, though more aggressive measures may be required.

Injury to facial nerve branches often accompanies injury to the parotid gland. If evidence of paralysis in one or more regions of the seventh nerve is found on physical examination, an attempt at primary microsurgical reanastomosis should be made at the time of initial wound repair.

image Facial Skeleton

Approaches

If facial lacerations exist, they may provide adequate exposure with minimal extension. Otherwise, the principles of soft tissue approaches include minimizing (and avoiding) incisions in facial skin and protecting neurovascular structures while achieving maximal exposure.

The coronal approach exposes the entire upper face down to the nasal bones as well as the anterior calvarium, lateral orbital rims, and zygomas.22,23 The scalp is incised in serpentine, geometric, or gently curved (Soutar) fashion from the root of one auricular helix to the other. A scalp flap is raised anteriorly in either the subgaleal or the subperiosteal plane between the temporal lines. If a pericranial flap will be harvested, the subgaleal plane is often followed, leaving a healthy layer of loose areolar tissue down on the pericranium. Alternatively, the pericranium can be raised with the scalp and harvested from the scalp flap secondarily.

Extreme care is required to avoid injury to the temporal branches of the facial nerve. Dissection over the temporal fat pads can be performed either just over the deep temporal fascia, hugging the fascia to avoid nerve injury, or, to be safer, the deep fascia can be incised where it divides into two layers, and the dissection can be continued inferiorly just over the fat (Fig. 21-1 and Fig. 21-8A). The dissection can then be carried forward to the superior and lateral orbital rims and inferiorly to the zygomatic arches. Supratrochlear and supraorbital neurovascular bundles are carefully protected.

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FIGURE 21-8 Surgical approaches. (A) The left half of a coronal approach. The plane of dissection is carried deep to the superficial layer of deep temporal fascia thereby protecting the facial nerve. (B) The transconjunctival approach with the preseptal plane of dissection demonstrated. (C) The midface degloving approach combines bilateral sublabial approaches and circumferential incisions in the nasal vestibule, permitting access to nearly the entire midface. (Reproduced with permission from Kellman RM, Marentette LJ. Atlas of Craniomaxillofacial Fixation. New York: Raven Press; 1995: 98, 113, 116.)

Scalp closure is achieved in layers. A wide scar is prevented by taking particular care to reapproximate the galea. The skin may be sutured or stapled.

Exposure of the midface is obtained through either a sublabial or a midface degloving approach (Fig. 21-8B). After an incision in the superior oral vestibule is made perpendicular to mucosa and then deepened perpendicular to bone, a subperiosteal dissection over the face of the maxilla is performed, using care to avoid the infraorbital nerve.

When greater exposure is required, a bilateral sublabial approach may be converted to a midface degloving approach.24 Subperiosteal dissection is extended into the floor of the piriform aperture and into the nose. The nasal vestibule is incised circumferentially, connecting the nasal floor, membranous septum and intercartilagenous region. Thus, the lower one third of the nose is raised with the flap.

The orbits are directly approached through modified brow and blepharoplasty incisions.22,24 Although the brow incision for access to the lateral superior orbit and lateral orbital rim has been advocated for years, many surgeons have abandoned it in favor of the upper lid blepharoplasty incision.22 Lower lid blepharoplasty incisions provide the best direct exposure of the orbital floor and inferior, medial, and lateral walls. In the lower lid, a subciliary skin incision can provide access to the inferior rim and floor, but it does produce a facial scar (even though fine) and does carry greater risk of lid retraction than does an approach through the conjunctiva. The transconjunctival approach may include a lateral extension, which requires a canthotomy and inferior cantholysis. In this case, it is initiated with the lateral incision and canthotomy. Otherwise, only the conjunctival incision is used. The surgeon develops either a pre-or post-septal plane and carries the dissection to the inferior rim (Fig. 21-8C). The conjunctiva may be left open or is closed with a 6-0 fast absorbing gut suture.

The inferior oral vestibular approach exposes the mandibular symphysis and body. Subperiosteal dissection exposes the mental nerves and the anterior two thirds of the mandible. Closure is water-tight, and the soft tissue of the mentum must be resuspended from the skeleton. An incision along the anterior border of the ramus is used to expose the vertical mandibular structures, including the coronoid process, the sigmoid notch, and the condylar neck. This ramus approach combined with a transbuccal stab incision is usually adequate for reduction of a subcondylar, ramus, or angle fracture.

Occasionally, the mandible may be approached through external skin incisions. These are positioned in appropriate skin creases (relaxed skin tension lines), and care is taken to avoid branches of the facial nerve.

Fundamentals of Rigid Fixation

Skeletal support for the soft tissue and visceral structures of the face must be reconstituted. The surgeon reduces and fixates fractured skeletal elements in order to restore proper form and function and to optimize bony healing.22,2527 Interfragmentary motion prevents the formation of the delicate vascular support of growing bone, thereby preventing osteoblastic bone formation and the development of a stable population of osteocytes. Rigid fixation not only maintains alignment of bone segments, it also eliminates motion in the fracture gap.25 Lack of adequate fixation increases the chance of device failure and nonunion as well as wound infection and osteomyelitis.22,26,27

Traditional fixation for most of the 20th century was performed by wiring the teeth in occlusion using maxillomandibular fixation (MMF), frequently in combination with interosseous wiring. In the 1970s and 1980s, rigid fixation of the facial skeleton with plates and screws began to gain popularity, and these techniques now predominate.

Rigid fixation, as the name suggests, involves properly applying fixation devices to bone so that the dynamic forces of distraction in function are overcome. When properly adapted to bone using screws, a plate provides immobilization and strong, rigid splinting. Multiple plating strategies have been developed. Compression plates take advantage of eccentric, ramped screw holes that force the turning screw to slide down the shoulders of the screw hole, thereby bringing a bone fragment with it and compressing it against an opposing bone fragment (Fig. 21-9).22 Recently however, compression plates have fallen out of favor, not because they are ineffective, but as a result of comparably high success rates with the technically easier and more tolerant miniplate approaches. Miniplate technology reliably achieves complete healing with comparable success rates.28

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FIGURE 21-9 Compression plate fixation demonstrated. As the screw is driven against the ramped screw hole, the plate and bone are displaced in opposite directions, resulting in axial compression of the fracture segments. (Reproduced with permission from Kellman RM, Marentette LJ. Atlas of Craniomaxillofacial Fixation. New York: Raven Press; 1995:63.)

The newer “locking plates” add a margin of safety by fixing the screw heads to the plate itself. The heads of locking screws thread-lock to the plate hole, and functions more like an external fixator. Therefore, it requires less precision in adapting the plate.29

Compression fixation is also achieved with lag screws—either alone or in combination with a plate (Fig. 21-10). Lag screws can be used whenever bone fragments overlap or meet in a way that allows fixation of the screw in the second cortex.30

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FIGURE 21-10 Lag screw fixation of a manibular angle fracture through an inferior oral vestibular approach. Note that the proximal segment is overdrilled and that a countersink is created in its cortical surface. (Reproduced with permission from Kellman RM, Marentette LJ. Atlas of Craniomaxillofacial Fixation. New York: Raven Press; 1995:238.)

Titanium is currently the metal of choice for nearly all metal craniofacial plates. Titanium does not corrode and does not interfere with imaging, and it seems to “integrate” with bone, with osteocytes adhering directly to the material without a fibrous interface.31

Mandibular Repair

The goals of treatment are restoration of form, manifested by normal occlusion, and restoration of function, or the capacity to bear the load of mastication. Although many fractures could heal solely through the application of MMF, there is increased risk of malunion due to less dependability of maintenance of position and increased risk of nonunion due to lack of adequate stabilization. Therefore, most fractures are treated with open reduction and internal fixation (ORIF) so that healing is accelerated and patient comfort and safety are improved. Interestingly, there is even a recent trend toward completely avoiding the application of arch bars and proceeding directly to rigid fixation of the fracture fragments, though this approach remains quite controversial. It is certainly agreed, however, that there are benefits of avoiding postoperative MMF, particularly in the patient with a traumatic brain injury or one who is seizure prone. Still, most maxillofacial repair is started with application of arch bars and wires.

As noted above, the goal of rigid fixation is to overcome the forces that will tend to distract the fracture fragments. To accomplish this, Champy et al.32 proposed “ideal lines” of osteosynthesis, along which miniplates should be placed (Fig. 21-11). With tension at the superior border and compressive forces at the inferior border of symphysis, parasymphsysis, and body fractures, Champy demonstrated the mechanical advantage of placing a “tension band” plate across the superior border. For fractures of the symphysis and parasymphysis, Champy proposed a second plate, placed inferiorly to overcome any rotational forces. Champy’s technique also suggests that a single miniplate along the ideal line will stabilize a body or angle fracture of the mandible, though several groups have demonstrated better outcomes when two miniplates are fixed at the angle.33,34 Increasingly sophisticated techniques, including computer modeling, have demonstrated the differential loads borne by discrete areas of the mandible relative to the placement of fracture lines and bite force.35

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FIGURE 21-11 Dotted lines represent “Champy’s Ideal Line of Osteosynthesis” as defined by Professor Maxime Champy. Miniplate fixation along these lines counteracts the predominant forces acting in each region. (Reproduced with permission from Kellman RM, Marentette LJ. Atlas of Craniomaxillofacial Fixation. New York: Raven Press; 1995:43.)

Management of condylar and subcondylar fractures remains controversial. Although it is widely agreed that fractures of the condyle and the subcondylar region may cause a significant disturbance of masticatory movement, the patient’s ability to adapt to such a disturbance may be great.36 Furthermore, there has been great concern about the risk of facial nerve injury when open reduction of these fractures is performed. This has led to decreased use of open reduction, a choice made more acceptable by the tolerable results seen with closed treatment. It should be noted, however, that closed approaches do not reduce these fractures, so that the term “closed reduction” should be removed from the lexicon. Instead, it should be called “closed management,” with the realization that management of the occlusion is a form of “forced adaptation” of the occlusion to a less than ideal anatomic position of the underlying bone. Furthermore, despite the development of a “functional occlusion” in most cases, this result is achieved at the expense of physiologic adaptation, including altered kinematics of the jaw while chewing37 and possible foreshortening of the mandible on the fractured side. This may produce significant facial asymmetry at rest and with mouth opening.36,38,39 Moreover, some patients may not be capable of adaptation, and altered jaw movement may result in chronic pain or trismus.36,37

Recently, a randomized, prospective, multiinstitutional study in Europe has demonstrated a fairly clear advantage to open reduction of subcondylar fractures of the mandible. It is an excellent study, and the reader is referred to the original publication for further elaboration.40

The introduction of the endoscope into the armamentarium of the maxillofacial trauma surgeon may minimize the main concern associated with open reduction of subcondylar fractures of the mandible.39,41The endoscope allows for an intraoral approach and has been shown to reduce the risk of injury to the facial nerve and to eliminate facial scarring while effecting excellent results in selected patients39,41,42(Fig. 21-12).

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FIGURE 21-12 Endoscopic subcondylar fracture repair. (A) Frame of a coronal computed tomographic scan demonstrating a right subcondylar fracture with lateral overlap of the proximal fragment. (B) Lateral overlap of the proximal fragment as seen through the endoscope. (C) Artist’s depiction of B. (D) Wire through the angle of the mandible. Inset, inferior traction on the distal fragment allows the proximal fragment to fall into a reduced position. (E) Proximal fragment falling into place as inferior traction is applied. (F) Artist’s depiction of E. (G) Threaded fragment manipulator being passed through the right cheek. (H) The manipulator in position over the proximal fragment. (I) Artist’s depiction of the manipulator passing through the proximal plate hole into the proximal bone fragment. (J) Endoscopic view of the reduced fracture after plate placement is complete. (Reproduced with permission from Kellman RM. Endoscopically assisted repair of subcondylar fractures of the mandible: an evolving technique. Arch Facial Plast Surg. 2003;5:244. Copyright © 2003 American Medical Association. All rights reserved.)

Note that when a segment of mandible is severely injured with comminution or bone loss, miniplate fixation cannot provide adequate stability. A mandibular reconstruction plate is fixated to adequate proximal and distal bone stock, incorporating the comminuted fragments between.11,22 The reconstruction plate is a large plate fixed with multiple fixation points, so that it can provide a “replacement” for bone that is either missing or unable to provide support. Comminuted fragments may be fixed to one another with miniplates or wires or lagged to the reconstruction plate. Note, however, that not only is bending a heavy reconstruction plate more difficult than bending a miniplate, greater precision in adapting reconstruction plates is required to avoid creating an uncorrectable malocclusion.

Midface

The forces acting across midface fractures are far less than those found in mandibular fractures. Occlusal forces impart only compressive forces to the medial and lateral buttress, and the masseter muscle imparts only mild-to-moderate amounts of shearing and rotation to a fractured zygoma.22 Thus, repair considerations focus less on the fixation strategy than on the realignment of skeletal elements so that the buttresses are restored and soft tissue and visceral structures are properly supported. In general, single miniplate fixation of buttresses and microplate fixation of intervening segments are sufficient.

Repair of lower midface or Le Fort I fractures involves exposure of the bones, disimpaction of the midface, realignment of fracture segments, and plating of the vertical buttresses. Primary principles are the restoration of occlusion and vertical facial height. After reduction, the bones are secured in position with small plates and screws, and MMF is then released. Comminution complicates repair, and gaps should be spanned by bone grafts from the calvarium, rib, or iliac crest.43

Upper midface (middle third) fractures include buttress fractures in the Le Fort II and III pattern, as well as fractures through the orbital walls and zygomatic articulations. The maxillary vestibular approach is again utilized to approach the upper midface in combination with the transconjuntival approach to the orbital rims and floor. The buttresses are reduced and plated. Nasal root exposure may sometimes be required, as well.

The midface may also transmit force to the deeper skeletal elements of the orbit. Therefore, after the lateral buttress and orbital rims are approached and repaired, the orbital walls, especially the floor, are explored when necessary, and reconstructed with an appropriate alloplastic or autogenous material.

Le Fort II and III fractures also imply disruption of the nasal pyramid. The medial buttress is plated superiorly, reestablishing the frontal process of the maxilla and the medial orbital rim. A strong tendency for posterior rotation of the lower facial skeleton, hinged at the nasal root, is an indication for plating nasal fractures, and stabilizing the nasal root to the frontal bone. Defects in the nasal dorsum may be repaired with a free bone graft cantilevered from the glabella.22

Most recently, endoscopic repair of the orbital floor and medial wall fractures has been described. The floor is approached through the maxillary vestibular incision and an anterior maxillotomy. This approach avoids possible complications of eyelid incisions and may afford better visualization of the posterior orbital floor. The orbital contents are reduced and the floor is grafted44 (Fig. 21-13). There is a risk, however, of inadvertently pushing bone fragments into the orbit from below. Endoscopic approaches to medial orbital fractures has also been recently advocated.45,46 These are performed through the nose by exposing the fractures through the ethmoid sinus.

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FIGURE 21-13 Orbital floor repair using autogenous bone graft. The graft is fixed to the inferior orbital rim. Multiple pieces may be plated or wired together in order to account for defects with complex shapes. (Reproduced with permission from Kellman RM, Marentette LJ. Atlas of Craniomaxillofacial Fixation. New York: Raven Press; 1995:293.)

Forces directed at the nasal root may lead to telescoping inward of the strong nasal bone as the weaker laminae of the medial orbital walls give way, allowing the lacrimal bones to splay, thereby causing telecanthus (pseudohypertelorism). This is the NOE fracture. For the purpose of repair, NOE fractures are categorized as types I, II, and III, depending on the severity of disruption of the medial canthal ligaments47 (Fig. 21-14). Type I injuries result in a large central fragment with the medial canthal ligament attached to it. Fixing this fragment above and below will stabilize the ligament in place as well. Type II fractures involve comminution of the central fragment without avulsion of the medial canthal ligament. Therefore, fixation should be augmented by transnasal fixation of the medial canthi with 28 gauge wire or 2-0 permanent suture.47 Type III injuries involve severe comminution of the NOE complex and avulsion of the medial canthus. In this case, the stumps of the canthi are approximated with a wire or permanent suture that crosses the nasal septum. Comminuted fragments are microplated or free bone grafts are used to span any gap between the medial buttress and the frontal bone.48 Often severe NOE injuries involve the lacrimal system, which should be probed and stented.

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FIGURE 21-14 Naso-orbito-ethmoid fracture classification.

Zygoma fractures may be isolated to the arch or may involve the entire “ZMC” or “tripod.” Simple, nondisplaced fractures of the arch may be treated with observation. Displacement, however, may result in impingement of the temporalis muscle and dimpling of the cheek and should be reduced. Classically, this is accomplished via an external, Gilles incision in the temporal hair tuft or a sublabial incision. The fracture is reduced with an elevator. Most displaced ZMC fractures require ORIF. Nondisplaced fractures may be observed and, since many displaced fractures result only in cosmetic rather than functional deficits, patients may decline surgical repair. The central principle of repair is fracture realignment and fixation to reestablish the malar prominence. Although the zygomaticosphenoid (ZS) suture may be overlooked, it often provides the key information in determining final ZMC reduction. In addition, malalignment of the ZS articulation can result in a significant step-off in the lateral orbital wall and change in the orbital volume.

Upper facial fractures consist of either anterior cranial vault fractures, beyond the scope of this chapter, or frontal sinus fractures and the occasional superior orbital rim fracture. Frontal sinus fractures may be isolated, but often occur in the setting of upper midface fractures including Le Fort II and III and NOE injuries (Fig. 21-15). Multiple algorithms for the evaluation and repair of frontal sinus injuries are described.48,49 The principles of treatment include reestablishing an aesthetic anterior wall, ensuring the function of the frontal sinus should it be preserved, and safe management of a possible leak of CSF or exposure of the brain. Despite minor variations, the authors agree that the following distinctions determine the treatment needed to achieve those principles: (1) site of fracture—anterior versus posterior table; (2) degree of fracture displacement in either the anterior or the posterior wall; (3) the presence of fractures through the NFD, and (4) the presence of possible CSF leak.

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FIGURE 21-15 Variation in severe panfacial fractures. (A) Coronal computed tomography (CT) demonstrating left Le Fort III, frontal sinus, naso-orbital ethmoid (NOE), and bilateral Le Fort I fractures as well as a split palate. (B) Three-dimensional CT demonstrating severely comminuted frontal sinus, bilateral Le Fort III, left Le Fort II, NOE, and bilateral high Le Fort I fractures. Both injuries resulted from high-speed motor vehicle accidents.

Nondisplaced fractures of the anterior table can be observed. Anterior table fractures with significant depression or displacement should be repaired for cosmetic reasons, though the patient may opt for observation, utilizing delayed repair if a significant cosmetic deformity develops. Nondisplaced fractures of the posterior wall can also be observed. Classically, displacement of posterior table fractures greater than the width of the posterior table itself has been used as an indication for exploration. The fear is communication between the frontal sinus and the intracranial compartment with increased risk of dural tear, CSF leak, and meningitis.48,49 In reality, any displacement suggests these risks, though obviously, increasing severity of a posterior table fracture including the presence of CSF leak mandates increasingly aggressive treatment. Fractures that traverse the floor of the sinus, especially medially, are likely to produce dysfunction of the NFD. Possible sequelae include frontal sinusitis, mucocele, and mucopyocele. Thus, involvement of the NFD in anterior or posterior table fractures requires more aggressive management. Minimal or questionable fractures through the sinus floor or posterior table can be further assessed via endoscopy for the presence of CSF leak or obstruction of the NFD.

Management options include observation, observation with medical management including antibiotic coverage, ORIF, sinus and duct obliteration, and sinus cranialization with duct obliteration.

In reality, upper face and midface fractures most commonly occur in combination as the result of high-speed motor vehicle accidents and may also present with lower facial injuries. Although such “pan-facial” fractures represent daunting challenges to the surgeon, the authors and others espouse a “subunit” approach, by which complex fractures are repaired sequentially, thereby creating less complexity with each step of the repair.7,22 Classical approaches have been described as either “outside-in” or “inside out”; that is, from the periphery toward the center or vice versa. The authors use somewhat of a combined approach, first stabilizing the occlusion and then proceeding from the periphery toward the center (“outside-in”). The central midface is the most dependent portion of the craniofacial skeleton, providing the least in terms of native strength. Facial height and projection is, therefore, established through reconstitution of the mandible and the maxillary alveolus below and the cranial vault and upper midface above. The zygomatic arches relate the upper midface to the cranial base posteriorly. The vertical and horizontal buttresses are then reconstituted, and the upper and lower halves of the craniofacial skeleton are thus linked, with occlusion as the primary determinant of the final position. The central midface is addressed last, repairing telecanthus and restoring projection of the nasal root.

Proper reduction of the mandibular arch is key.11 If the mandible is incompletely reduced and then used to set the midfacial width, height, and projection via occlusal relationships, a wide and insufficiently projected midface results.

Finally, fractures of the frontal sinus and the upper midface, especially the NOE complex, may well result in disruption of the anterior skull base. Severely comminuted fractures of the frontal sinus, suspected dural lacerations, or impingement on the optic nerve suggest fractures of the anterior skull base. In this case, the authors perform a subcranial approach to the anterior skull base. This involves temporary removal of the nasoglabellar complex and a variable extent of the superior orbital rims and frontal calvarium.50 This approach affords superior exposure of the frontal lobe dura and anterior skull base with minimal retraction of the brain. The medial canthi are also directly exposed, simplifying telecanthus repair.50

MASSIVE WOUNDS

High-energy insults resulting in massive full-thickness wounds to the face deserve particular attention. These include both high-speed motor vehicular trauma and close-range gunshot injuries. Management of such wounds is complex; however, primary principles and treatment approaches that maximize success have been be identified (Fig. 21-16).8,51,52 Blast wounds to the face require immediate stabilization of remaining skeletal elements, especially the mandible and midfacial buttresses, and closure of overlying soft tissue. Delay results in severe retraction of soft tissue and devitalization of the underlying skeleton. Large bony defects should be spanned by reconstruction plates in the mandible or by miniplates and bone grafts in the midface and cranial vault. Debridement in the zone of injury is repeated over the first several days until further tissue loss is not encountered. Early reconstruction utilizing local and regional tissue provides an aesthetic outcome far superior to that obtained by delayed secondary repair including free tissue transfer.8,52 Where free tissue transfer is needed, one should expect that more than one flap will be needed. Finally, Clark et al.8 suggest that lack of lining tissue in the oral cavity and sinuses is an underappreciated cause of infection and failure of bone grafting.

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FIGURE 21-16 An approach to maxillofacial and mandibular injury.

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52. Yuksel F, Celikoz B, Ergun O, et al. Management of maxillofacial problems in self-inflicted rifle wounds. Ann Plast Surg. 2004;53:111–117.