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

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.^2–4 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.^2–4

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

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.

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.

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.

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.

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.

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.

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

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).

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

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.

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.

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.

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

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