Chapter 8. Maxillofacial Trauma

Patients with maxillofacial trauma are seen everyday in emergency rooms throughout the United States. The cause of the trauma can be quite variable, ranging from industrial and motor vehicle accidents to interpersonal trauma involving either fists or weapons. It is common for trauma to be related to substance abuse or to behavior that can be linked to substance abuse. Sometimes trauma is related to sports activities or simply to accidental or work-related occurrences. The principles of management are directed at stabilizing a patient's medical condition and providing safe reconstruction to maximize both functional and aesthetic rehabilitation.

The ABCs of Trauma

It can be disconcerting when a patient is brought into the emergency room with severe craniofacial trauma. Patients may be covered with blood and have distorted anatomy that may divert attention from the initial principles of Advanced Trauma Life Support (ATLS). In these circumstances, it is critically important to follow the basic tenets of initial trauma stabilization, also known as the ABCs of trauma:

• Airway management and assessment
• Breathing
• Circulation

Tamponade of bleeding and C-spine clearance are also critical factors when the patient initially presents to the emergency room. In the initial management period, even occurrences of severe craniofacial trauma may be examined after cases of abdominal, thoracic, and—at times—limb trauma. A neurosurgical examination and clearance are frequently desirable in severe high-velocity injuries. When ocular injury is suspected, an examination by an ophthalmologist can be indispensable. Patients on the most severe end of the injury spectrum often require airway control via orotracheal intubation or, in certain cases, via cricothyroidotomy or tracheotomy.

Most attempts to repair maxillofacial trauma will be considered after the patient is stabilized. Almost all skeletal trauma repair is guided by the information provided by fine-cut computed tomography (CT) scans. Fine-cut scans take more time and require more medical condition stability than the initial screening provided by head and brain CT scans, which are often obtained to rule out suspected neurological injury during the initial, acute evaluation period. In contrast, soft-tissue injuries are often repaired as soon as it is practically possible. Low-velocity injuries, such as isolated nasal and mandible fractures, do not usually require the same highly consultative and collaborative team approach, especially if no other injuries are found or suspected. With isolated injuries, which tend to be more minor than multisystem injuries, treatment can be better directed; it can proceed on a pace both commensurate with and concentrated upon the direct injury.

Essentials of Diagnosis

• Obtain hemostasis
• Tetanus prophylaxis
• Irrigate/clean wound
• Meticulous layered closure

Treatment

Managing Blood Loss

Although the ABCs of trauma take precedence over most of the issues associated with maxillofacial trauma, sometimes the soft tissue injuries of the face or scalp can add substantially to blood loss. A temporal injury may lacerate the superficial temporal artery or a scalp laceration may contribute to the loss of many units of blood. Under these circumstances, it is desirable to halt bleeding immediately. The discrete clamping of an arterial vessel in a laceration may be necessary if the physician is unable to gain adequate control of blood loss by applying simple pressure. Scalp injuries usually respond to closure with a few simple mattress sutures, placement of staples to approximate the wound, or a pressure dressing. This blood loss management allows time for the rest of the trauma evaluation to proceed and for the patient to be stabilized.

Prophylactic Treatment Measures

Antibiotics

Lacerations of the scalp, face, and neck should be closed as soon as the patient is stable. In cases in which the tissue loss is minimal, which is the most common circumstance, primary closure is utilized. Primary closure is direct edge-to-edge skin approximation using fine sutures with precise suture approximation of deeper tissue layers. Protecting the patient prophylactically with tetanus immunoglobulin and tetanus toxoid should be considered. In contaminated wounds, which are extremely common, prophylactic antibiotic administration should also be considered.

Anesthesia

It is important to administer adequate anesthesia for wound closure if the closure is to be made under local sedation. Typically, injectable 1% lidocaine with epinephrine mixed 1:100,000 is adequate to obtain anesthesia for closure. This preparation can be injected with a fine, 27-gauge needle and a control-type syringe. The toxic dose of lidocaine with epinephrine is 7 mg/kg and should be noted. During the procedure, it is often possible to keep the patient comfortable with a small amount of sedation if no contraindication exists. Sometimes topical EMLA cream (lidocaine 2.5% and prilocaine 2.5%) can be used if it is difficult to inject the patient (eg, a child) with a local anesthetic agent.

Wound Irrigation

Once anesthesia takes effect, the wound should be irrigated to help prevent future infection. However, irrigation can only be done effectively if the patient is comfortable. Saline can usually be used to irrigate the wound with a 60-mL syringe. If glass, gravel, or other foreign material is suspected to be in the wound, a finger can be used to probe the wound and remove the foreign material. Sometimes the skin is abraded so badly that the area needing to be anesthetized would be too large to safely administer lidocaine to the patient without causing lidocaine toxicity. In these cases, it is best to proceed to the operating room so that general anesthesia can be administered and the wound can be manipulated without the risk of excessive local anesthesia (Figure 8–1). In some wounds contaminated by tar, as sometimes occurs in motorcycle accidents or other road injuries, administering general anesthesia is the best recommended option for wound manipulation that is comfortable for the patient. Once the wound is thoroughly clean, povidone–iodine, commonly known as Betadine, can be used to create a sterile environment for wound closure. Any small bleeding areas can be handled with a disposable electric cautery, bipolar cautery, or by using individual clamps and suture ties.

Wound Closure

Facial wound closure should heal by first-intention (primary) healing whenever possible; lacerations should be closed with direct suturing to approximate skin edges. This closure can be improved with the discrete undermining of skin flaps, where necessary, to produce a tension-free closure. The key elements to obtaining good results with wound closure are (1) having a clean and sterile wound, (2) respecting anatomic boundaries, (3) avoiding tension on the suture line, and (4) having atraumatic surgical technique. The wound should be closed in layers, in the following order: (1) muscle, (2) subcutaneous tissue, (3) subcuticular tissue, and (4) superficial skin. Chromic gut sutures are useful for deep closure; fine nylon or proline stitches are useful for skin closure. Although polyglactin (eg, Vicryl) and polyglycolic acid (eg, Dexon) can also be used for deep stitches, they can sometimes become infected due to sluggish absorption, which can lead to their eventual migration out of the wound. Other dissolvable monofilament sutures may also be used for deep closure. In areas where it is difficult to remove stitches, such as around the eyelid, fast-absorbing 6–0 gut sutures or 6–0 mild chromic sutures can be used. These sutures have the advantage of leaving little trace of their placement and dissolving without requiring removal. These types of stitches may also be useful in children to prevent the need for future stitch removal or when patient follow-up is doubtful. When taking care of patients with heavy beards or dark facial hair, it is best to use a skin suture color other than black to facilitate future removal. Blue proline suture works well in these circumstances.

If wound coverage is difficult because of lost skin, transposition flaps can be used to create closure. However, these flaps are rarely necessary. If they are required, it is often best to accomplish the closure in the operating room setting as instrument sets and nursing assistance become more critical. The risk in using transposition flaps is that the wound is usually contaminated; utilizing these flaps may increase the risk of tissue loss if the wound becomes infected. In these cases, wounds may be allowed to heal by second-intention (secondary) healing through the granulation and contracture process with a subsequent plan, if necessary, for wound revision.

A special circumstance of trauma involves bite injuries, which may be of animal, insect, or human origin. Allowing a bite injury to heal by first-intention healing should be considered carefully because the wound is likely to be contaminated. Although infection may ensue, primary closure is still recommended for these wounds after thorough irrigation and with concomitant antibiotic administration. The antibiotic coverage should be directed at a polymicrobial spectrum, including α-hemolytic streptococci, Staphylococcus aureus, and anaerobes such as Bacteroides. β-lactamase stable antibiotics such as amoxicillin–clavulanic acid combination drugs are good targeted medications for prophylaxis of these types of injuries. It is likely that the result will be no worse if an attempt at closure is made, even if the wound eventually becomes infected compared with leaving the wound open to heal by second intention.

During the acute management of patients with facial burns, the fundamental principles of trauma are followed. Special attention must be directed to evaluation of the airway because airway obstruction may develop rapidly after inhalation injury. Delayed onset of obstruction within 24–48 hours may occur from progressive edema. Specific risk factors for airway compromise include a history of burn injury within a confined space, evidence of soot in the oral cavity, production of carbonaceous sputum, and concomitant facial and body burns. Laboratory evidence, including arterial blood gases and carboxyhemoglobin levels, may further suggest potential airway impairment. If time permits, serial flexible fiberoptic nasolaryngoscopy exams allow for diagnosis of oropharyngeal, true and false vocal fold edema. In management of burn patients, there should be a low threshold for early intubation.

Burns are broadly classified according to depth of penetration. First-degree burns involve the epidermis only (eg, sunburn), and clinical findings include erythema. Second-degree or partial-thickness burns involve the epidermis and a portion of the dermis. These burns are extremely painful and present with blistering and open, weeping surfaces of skin. Third-degree or full-thickness burns represent involvement of all layers of skin, including nerve endings, blood vessels, and skin appendages. As such, they are characterized as insensate, swollen, and white or gray in color. Extent of burn injury is estimated by the “rule of nines,” whereby the head and neck region represents approximately 9% of total body surface area.

Inpatient management is universally required for second- or third-degree burns of the face. Early treatment goals involve the prevention of infection via sterile dressings, burn excision, and wound closure if permissible. To attenuate contracture and scar formation, temporary wound cover may be accomplished with cadaver grafts, porcine grafts, and a variety of synthetic skin substitutes. Permanent wound coverage is obtained by split-thickness skin grafts, local flaps, or microvascular free tissue transfer. Microstomia commonly results from perioral facial burns, or thermal burns that occur when small children chew electric cords. Oral splints are available for prevention of microstomia, but the efficacy of these appliances is controversial. Contracture of the eyelid, or ectropion, occurs when the eyelids are everted from the globes following burn injury. Early ophthalmologic consultation is recommended. To prevent corneal damage, early reestablishment of lid position is imperative.

The forces of traumatic impact have a fairly predictable effect on the facial skeleton: most force is directed through the buttress system. The buttresses consist of both vertical and horizontal supports. The horizontal buttresses are (1) the zygomatic arches, (2) the supraorbital and infraorbital rims, and (3) the glabella or nasal root (Figure 8–2). The vertical buttresses consist of (1) the frontozygomatic buttresses; (2) the maxillary buttress of the pterygoid plate; (3) the posterolateral maxillary sinus wall, which is known as the zygomaticomaxillary buttress; and (4) the frontoethmoid maxillary buttress (Figure 8–3). The successful repair of midface skeletal fractures requires an understanding of the impact of forces on the skeletal buttresses; it also requires a recognition of the weakness patterns common to this buttress system. In general, the midface creates a vertical maxillary dentition and palate height that needs to be maintained if the repair process is to maximize function.

Orbital Fractures

Essentials of Diagnosis

• Ophthalmological examination is critically important
• Fine cut CT scan is necessary for treatment planning

Orbital fractures may occur either as a part of massive facial trauma, in conjunction with Le Fort fractures, or as isolated fractures. Orbital floor fractures known as blowout fractures are commonly encountered as isolated fractures. The mechanism of injury for these fractures is usually from direct anterior orbital trauma, such as from a fist or from a ball during a sporting activity. The orbit is made up of buttresses connected by very thin bones that include maxilla, sphenoid, lacrimal, frontal, zygomatic, ethmoid, and palatine bones. The orbital floor is also the roof of the maxillary sinus and has a natural weakness where the second division of the trigeminal nerve traverses it; the bone in this area is quite thin. Sudden anterior pressure on the orbital contents can cause a fracture of the orbital floor, which results in periorbital fat sagging into the maxillary sinus. In some cases, the inferior orbital rim may be involved at the level of the infraorbital foramen, which may also result in numbness in the V2 distribution (ie, the second division of the trigeminal nerve).

Not all orbital floor fractures require exploration and repair. Orbital fractures need surgical intervention under the following circumstances: (1) they cause entrapment of the extraocular muscles, resulting in gaze limitation or diplopia; (2) the patient has sagging of the orbital contents, causing enophthalmos and subsequent diplopia; or (3) imaging studies reveal a greatly increased relative orbital volume (greater than 5–10% relative increase when compared with the noninjured side) due to the loss of the orbital floor and sagging of the contents into the maxillary sinus. In this latter scenario, the patient is at risk for late enophthalmos, and repair would be more easily accomplished within a few weeks of the injury rather than months later, when scarring will cause the procedure to be more difficult. It is highly recommended to obtain a baseline ophthalmologic exam of vision acuity and range of motion for all patients with orbital fractures, especially before proceeding with operative repair. A fine-cut axial and coronal CT scan of the orbits is essential for operative planning. The ideal time for the repair is often 7–14 days after the injury; much of the edema from the trauma will have subsided, and the repair technique will be easier to precisely gauge. The operative technique involves either a subciliary or a transconjunctival incision, both of which give access to the orbital periosteum. The orbital contents are then raised out of the fracture line and supported with a titanium plate, cartilage, bone, absorbable plate, or other material. Many permanent orbital implant materials have a long history of use, including Medpore (ie, porous polyethylene), Marlex (ie, polypropylene mesh), silicone, and other materials. They all have the possibility of late extrusion. Titanium has the advantage of being able to be fixed to bone via screws, which decreases the chance of late migration. Titanium is also biocompatible. Combination implants consisting of porous polyethylene wrapped around a titanium framework are available, which have the advantage of being malleable and impervious to soft tissue growing through the titanium lattice. Conchal or nasal cartilage is autologous and is therefore a good material for supporting orbital repairs of this type. After the repair is completed, a forced duction test of extraocular motility should be performed to ensure that any entrapment of the extraocular muscles is relieved.

Nasoethmoid Complex Fractures

Essentials of Diagnosis

• Condition of the medial canthal tendon is critical in the decision making process
• CT scan is vital diagnosis and planning

The nasoethmoid complex involves both a horizontal and a vertical buttress. The horizontal buttress is the nasal root, and the vertical buttress is the frontonasal maxillary pillar. Nasoethmoid complex fractures usually require high velocity and a more powerful force in order to be produced compared with isolated nasal fractures or orbital floor fractures. The key physical findings are often severe orbital swelling and ecchymosis with traumatic telecanthus (widening of the intercanthal distance), which gives the impression of widening of the eyes. Because of the close proximity of the ethmoid bone to the skull base, skull base trauma and cerebrospinal fluid (CSF) leak should be suspected in patients who sustain nasoethmoid complex fractures; neurosurgical consultation is therefore advisable.

Because the anterior ethmoid cells have an impact on frontal sinus drainage, patients with severe nasoethmoid complex fractures may require follow-up to ensure that the frontal sinus drainage is physiologically functional. If it is not, a late frontoethmoid or frontal sinus mucocele may occur, with the potential for eye or brain involvement. The key to repairing nasoethmoid complex fractures is the reestablishment of the midline vertical height of the nasal root. Reestablishing the midline vertical height prevents late deformity and restores the medial canthal tendon to an anatomically functional position. It is important to keep in mind that the normal intercanthal distance is 30–35 mm.

The surgical approach to repair a nasoethmoid complex fracture is often accomplished through a bicoronal forehead flap, which gives an excellent exposure of the nasal root to allow fracture reduction. Alternative techniques include a midfacial degloving incision or a bilateral external ethmoidectomy incision with a connection via the glabella; the latter procedure is known as the “open sky” approach. Small midface plates in various configurations can be used to painstakingly replace the shattered nasal and ethmoid bones into their anatomic positions. Bone grafts may be required if the fracture has a high degree of comminution. Occasionally, the medial canthal tendons must be retrieved and reapproximated with fine-gauge stainless-steel wire, either to titanium plates or to holes drilled in the lacrimal bone. Late diplopia can occur if the medial orbital attachments are not replaced optimally.

Zygomatic Complex Fractures

The zygomatic complex, also known as the trimalar complex, is a facial bone commonly injured in low-velocity trauma. Lateral trauma sometimes produces an isolated zygomatic arch fracture; however, more severe force can fracture the entire zygomatic complex. Although commonly referred to as a “tripod” fracture, this name is a misnomer: a zygomatic complex fracture constitutes four discrete fractures. The components of this fracture are (1) the zygomatic arch, (2) the orbital rim, (3) the frontozygomatic buttress, and (4) the zygomatico-maxillary buttress. Patients often present with infraorbital ecchymosis and occasionally with paresthesia in the V2 distribution. There is a loss of cheek prominence, with asymmetry upon inspection. The asymmetry can be most noticeable when the patient's head is tilted back and viewed from beneath the chin. Ophthalmologic consultation should be encouraged for a patient with a zygomatic complex fracture because the repair involves manipulating the inferior and lateral orbit walls, which may affect vision. Occasionally, tooth roots can also be involved in the fracture; therefore, an inspection of the dentition is recommended as part of the presenting history and physical exam.

The repair of zygomatic fractures is often accomplished on an elective basis. Isolated arch fractures can be elevated via a classic Gillies approach. The Gillies technique involves three steps: (1) creating an incision behind the temporal hairline, (2) identifying the temporalis fascia, and (3) placing an elevator beneath the fascia to approach the arch from its deep aspect. By sliding the elevator in the plane deep to the fascia, injury to the frontal branch of the facial nerve is avoided. The arch can then be levered into a more normal anatomic position. An alternate approach, called Keen's approach, is to place an elevator via a transoral gingival buccal sulcus incision underneath the arch; the elevator then passes through the buccal space with the elevation of the arch taking place. Zygomatic complex fractures can also be approached with the same transgingival buccal sulcus incision, which can give access as high as the orbital rim. One four-hole, midface titanium plate is enough to counteract the muscular forces to reduce and fix the fracture. However, it is usually desirable to expose at least two of the four buttresses in order to allow an accurate reduction of these fractures. A small incision at the lateral brow or superior eyelid crease may be necessary to access the frontozygomatic buttress and the sphenozygomatic buttress; alternately, a transconjunctival or subciliary or subtarsal incision may be needed to access the infraorbital rim (Figure 8–4). In rare cases, a bicoronal or a unicoronal approach may be used to obtain direct access to the zygomatic arch (1) if the fracture is very severe, (2) in cases of severe orbital-zygomatic fractures, or (3) in cases of bilateral zygomatic complex fractures. The main goals in operating on these fractures are to restore symmetry to the face and to prevent late orbital complications such as enophthalmos.

Maxillary Fractures

Essentials of Diagnosis

• Midface and palatal mobility can be defined on physical examination
• Occlusion must be corrected
• CT imaging is necessary for planning

Midface maxillary fractures are usually the result of high-velocity injuries (eg, motor vehicle accidents or severe and life-threatening interpersonal trauma). The primary surgical goals in repairing maxillary fractures include restoring normal contour to the facial skeleton and restoring normal dental occlusion.

Maxillary fractures were classified by René Le Fort. He subjected cadavers to various types of trauma and found that certain patterns of injury resulted. Le Fort divided these midface fractures into three discrete types: Le Fort I, Le Fort II, and Le Fort III. (Figures 7–2 and 7–3 display Le Fort fracture characteristics.)

Le Fort I Fractures

Le Fort I fractures are fractures that separate the palate from the midface and, by definition, involve the pterygoid plates bilaterally. This fracture type results in a mobile palate but a stable upper midface. Patients present with malocclusion and an anterior open-bite deformity. The deformity occurs because the pull of the muscles of mastication forces the palate to slide backward, retruding the maxillary teeth. Airway compromise can occur if the palate retrusion is severe. The operative strategy in repairing Le Fort I fractures is to reduce the fracture by aligning the dentition into as normal a configuration as possible.

Normal physiologic occlusion is referred to as Class I occlusion. It takes place when the mesiobuccal cusp of the maxillary first molar interdigitates with the mesiobuccal groove of the mandibular first molar. Class II occlusion occurs when the mandible is relatively retrognathic or retruded. Class III occlusion occurs when the mandible is relatively prognathic or protruded. The key goal in repairing any fracture involving the dentition is to reduce the fracture to the premorbid occlusion. This goal is best accomplished with a Class I occlusion. The surgical access for the repair of a Le Fort I fracture is often obtained via bilateral maxillary gingival buccal sulcus incisions; these incisions expose the anterior maxillary wall as well as the lateral and anterior maxillary buttresses. Intermaxillary fixation using either skeletal screws or arch bars with wires is used to pull the fractures into ideal occlusion. Occasionally, reduction forceps may be necessary to bring the palate back into functional occlusion. Once the fracture is reduced and stabilized, titanium miniplates, which have low profile but great strength, are screwed directly to the maxilla both to create permanent stability and, ideally, to restore midface height and functional occlusion. The blood supply to the maxilla is quite rich, and complications such as osteomyelitis or sequestrum occur rarely. Even small fragments of bone often survive if well fixed with the miniplate systems. If the fracture is so severe that no solid bone can be used to provide stable fixation, split calvarial bone grafts or grafts from the iliac crest can be plated into position to provide a stable repair. However, if the fracture is minimally displaced, sometimes intermaxillary fixation alone for 4–6 weeks will allow an excellent recovery.

Le Fort II Fractures

Le Fort II fractures involve the pterygoid plates, the frontonasal maxillary buttress, and often the skull base via the ethmoid bone. This fracture, therefore, has a pyramidal appearance and results in palatal and upper-midface mobility. Because of the large amount of force required to cause Le Fort II fractures, patients who have this type of fracture often have other injuries as well, including orthopedic and neurosurgical problems (Figure 8–5). The skull base may be involved, and so nasotracheal intubation should be avoided in the acute setting because a nasal tube could potentially be forced through the fracture and into an intracranial cavity. CSF leakage is common in this type of midface fracture. The initial medical stabilization is often accomplished in the intensive care unit. Fine-cut computerized imaging, usually CT scanning (possibly with three-dimensional reconstruction), is desirable as it allows for adequate operative planning once the patient's condition has stabilized (Figure 8–6). Patient stabilization often requires several days of convalescence.

The operative approach to Le Fort II fractures requires alignment of the dentition into Class I occlusion, using arch bars and wires or screws to reduce the fracture. This approach is known as intermaxillary fixation. Following intermaxillary fixation, the maxillary buttresses need to be surgically exposed to allow for miniplate fixation. Many strategies can be used to accomplish the exposure, including bilateral gingival buccal sulcus incisions together with incisions designed to approach nasoethmoid complex fractures. The midface degloving incision, which uses a rhinoplasty-type intranasal exposure, combined with the gingival buccal sulcus incisions, often provides excellent access to allow placing the titanium miniplates in this type of fracture.

Le Fort III Fractures

Le Fort III fractures involve the same types of force as Le Fort II fractures; however, Le Fort III fractures result from a greater degree of force than Le Fort II fractures. A consultative team approach is best for these severely injured patients. In addition to injuring the pterygoid plate and the frontonasal maxillary buttress (as is found with Le Fort II fractures), Le Fort III fractures involve the frontozygomatic buttress. These fractures therefore result in complete craniofacial dislocations. In addition, associated neurosurgical injuries are often seen in patients with Le Fort III fractures.

The preoperative issues associated with Le Fort III fractures are similar to those seen in Le Fort II cases. After intermaxillary fixation, a bicoronal approach is used to facilitate the repair of the frontozygomatic buttress and zygomatic arch. This approach allows excellent access to the lateral and medial buttress systems in order both to restore the adequate vertical height of the occlusion and to provide stable fixation. A midfacial degloving approach is often combined with the bicoronal approach to allow access to the lower maxilla for plating (Figure 8–7). It is not uncommon to recommend elective tracheotomy for these patients in the postoperative period. This approach is recommended for several reasons: (1) nasotracheal intubation is usually not safe for a patient with this degree of injury because of the risk of frontal skull base injury; (2) the patient must be placed into intermaxillary fixation; (3) owing to related neurosurgical issues, the patient usually has a fairly prolonged need for the attention of an intensive care unit; and (4) the reduction of this type of severe fracture also causes temporary but significant upper airway edema. Again, a team approach to the treatment of patients with this type of severe injury often increases the prognosis for a favorable recovery.

Mandible Fractures

Essentials of Diagnosis

• A panoramic radiograph or preferably CT imaging is best for diagnosis
• Intermaxillary fixation is a key principle to re-establish premorbid occlusion
• Many fixation techniques are available to permanently stabilize the fracture; some internal fixation techniques may allow immediate return to function

Mandible fractures can be part of both high-velocity and low-velocity traumas. Mandible fractures may occur as a result of sports activities, falls, motor vehicle accidents, and interpersonal trauma. In busy inner-city emergency departments, mandible fractures are seen almost daily. Patients often present acutely and may be intoxicated by alcohol or illicit substances. Patients sometimes present the morning after the injury, when they are no longer intoxicated and realize that a problem exists due to pain and malocclusion.

Patients with mandible fractures often have pain with attempts at mastication; this symptom usually results in their seeking medical attention. Other symptoms include malocclusion and numbness of the third division of the trigeminal nerve. The initial examination should note any sensory nerve deficit and associated dental injury, such as cracked or missing teeth. The mobility of a mandibular segment is a key physical diagnostic finding in confirming a mandible fracture. However, this mobility can vary with the location of the fracture. Fractures can occur in the anterior mandible (symphysial and parasymphysial), along the body of the mandible, at the angle of the mandible, or in the ramus or condylar regions (Figure 8–8). Most fractures of the symphysis, the mandible body, and the mandible angle are open fractures that will reveal mobility upon palpation. However, condyle fractures are extremely common; they typically are not open to the oral cavity and may only present as malocclusion with some pain.

Plain X-ray films are extremely helpful in determining both the presence and type of a mandible fracture. To help delineate the extent of the fractures, a mandible series usually consists of several different views: (1) a Towne's view to examine the condyles, (2) a submental-vertex view, (3) a posteroanterior view, and (4) both left and right lateral oblique views. Often, the fracture is bilateral; therefore, the presence of a right-body fracture should alert the physician to search carefully for a fracture on the opposite side. Panorex-view plain film X-rays help to delineate the condyle and angle regions and, if available, are excellent studies (Figure 8–9).

Mandible fractures may be displaced and distracted by the pull of the muscles of mastication. When this occurs, it is termed an unfavorable fracture. In contrast, some fractures form in such a way that the muscles of mastication tend to help keep the fracture well aligned; this type of fracture is termed a favorable fracture. Fractures in adolescents are often in excellent alignment because the bone is more flexible. These fractures are referred to as greenstick fractures and may require less immobilization time in order to heal.

A number of approaches allow for the optimal healing of a mandible fracture; however, the first step in fracture repair is the assessment of dental occlusion. The major principle in treating a mandible fracture is to place the patient into intermaxillary fixation; this positioning approximates the premorbid occlusion. In practice, this often means that the surgeon will try to reduce the fracture to produce a Class I occlusion. Placing a patient into intermaxillary fixation requires an assessment of the existing dentition and an inspection of the way in which the teeth interdigitate. Often, wear facets on the teeth can help guide the restoration of a good functional occlusion. The AO/ASIF (Arbeitsgemeinschaft Für Osteosynthese-fragen, the Association for the Study of Internal Fixation), a study group that crosses a number of specialty lines, developed and continues to refine fixation techniques. They have also established guidelines for closed and open rigid fixation.

Closed splinting approaches rely either on arch bars and intermaxillary fixation or on skeletal fixation with titanium screws. Immobilization for a period of 4–6 weeks is necessary to allow secondary bone healing. For condyle fractures, a lesser period of immobilization is usually preferred to avoid post-fracture joint ankylosis. IMF or intermaxillary fixation is accomplished when patients have their jaws wired into centric occlusion without the ability to open their mouths for an extended period of time. Patients must be on a liquid diet during the time period; many lose weight. If a patient becomes nauseated and vomits while his or her jaws are wired shut, there is a risk of aspiration with subsequent pneumonia; in the worst case, airway compromise is possible. Although this technique is the least surgically invasive approach, the disadvantages are that it (1) requires a great deal of patient cooperation, (2) requires close and intensive patient follow-up, and (3) can lead to functional temporomandibular joint problems owing to a prolonged lack of use. In patients with substance abuse issues, the lack of postoperative cooperation can lead to malunion, nonunion, and osteomyelitis, all with devastating effects. The advantages of extended immobilization are that (1) closed intermaxillary fixation minimizes risk to the mandibular and facial nerves; (2) it allows some flexibility in achieving the exact premorbid occlusion, thus minimizing the chance of iatrogenic malocclusion; and (3) it makes wound dehiscence extremely unlikely.

The advantage of open rigid fixation techniques is that fractures are stabilized with titanium plates and screws, essentially allowing functional mastication immediately after surgery. These plating systems can also allow primary bone healing due to the compression of the bone fracture segments, in contrast to secondary bone healing, which occurs through callus formation that occurs with other approximation techniques. Open rigid plating techniques also allow immediate postoperative function, which can help to prevent iatrogenic temporomandibular joint fixation caused by prolonged periods of immobilization (Figure 8–10). Nevertheless, plating techniques applied to the mandible are highly technique sensitive; iatrogenic postoperative malocclusion and injury to the mandibular, mental, or facial nerve and the teeth are known complications of the technique. The need for postoperative patient cooperation, however, is minimized with the adequate application of the AO principles.

Surgical approaches to mandible fractures can rely on either transoral or external incisions. Decisions must be made about whether to use compressive or noncompressive reconstruction plates, depending on the type and location of the fracture. Lag-screw and miniplate techniques (Champy techniques) can also play a role in the internal fixation of mandible fractures. The repair of these fractures is technique sensitive, however, and requires selective patient application. In addition, bilateral condylar fractures may be approached with minimally invasive endoscopic techniques.

Postoperatively, patients with mandible fractures are usually kept on oral antibiotic coverage and oral rinses with topical antimicrobial solutions such as chlorhexidine. Plate extrusion is fairly infrequent, but local infection with the loosening of screws and plates may need to be addressed with local debridement and placement of a heavier reconstruction plate system. Wound repair failures are more often due to the choice of an inadequate fixation system or a retained or cracked tooth root than to the rejection of the titanium hardware. If necessary, a transcutaneous external fixation system (known as a Joe Hall Morris appliance) may be useful, although the need to resort to this type of external fixation is rare.