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.
- 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.
Dal Canto AJ, Linberg JV. Comparison of orbital fracture repair performed within 14 days versus 15 to 29 days after trauma. Ophthal Plast Reconstr Surg
2008 Nov–Dec;24(6):437–443. [PubMed
]. (The question of timing of the orbital floor repair is controversial—this paper compares the early and late group up to 29 days and finds no significant difference in success.)
Manolidis S, Weeks BH, Kirby M, Scarlett M, Hollier L. Classification and surgical management of orbital fractures: experience with 111 orbital reconstructions. J Craniofac Surg
. (An excellent review of methods of orbital fracture repair.)
Manson PN. The orbit after Converse: seeing what is not there. J Craniofac Surg
2004 May;15(3):363–367. [PubMed
]. (Well worth the read, this lecture summarizes the history of orbital surgery from the time of Converse to contemporary practice.)
Ridgway EB, Chen C, Colakoglu S, Gautam S, Lee BT. The incidence of lower eyelid malposition after facial fracture repair: a retrospective study and meta-analysis comparing subtarsal, subciliary, and transconjunctival incisions. Plast Reconstr Surg
2009 Nov;124(5):1578–1586 [PubMed
]. (A single institution experience with 3 different surgical approaches combined with a literature meta-analysis.)
Nasoethmoid Complex Fractures
- 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.
Cultrara A, Turk JB, Har-El G. Midfacial degloving approach for repair of naso-orbital-ethmoid and midfacial fractures. Arch Facial Plast Surg
. (An excellent discussion of a useful surgical approach to facial trauma.)
Potter JK, Muzaffar AR, Ellis E et al. Aesthetic management of the nasal component of naso-orbital ethmoid fractures. Plast Reconstr Surg
. (A definitive and well-organized article that emphasizes treatment principles.)
Sargent La, Rogers GF. Nasoethmoid complex fractures: diagnosis and management. J Craniomaxillofacial Trauma
. (A good review of NEC fractures.)
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.
A midface reconstruction plate placed on the orbital rim via a subciliary approach.
Manson PN, Clark N, Robertson B et al. Subunit principles in midface fractures: the importance of sagittal buttresses, soft-tissue reductions, and sequencing treatment of segmental fractures. Plast Reconstr Surg
. (A definitive and well-organized review article that emphasizes treatment principles.)
Rinehart GC, Marsh JL, Hemmer KM, Bresina S. Internal fixation of malar fractures: an experimental biophysical study. Plast Reconstr Surg
. (A good study of the forces needed to stabilize ZMC fractures.)
- 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 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 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.
A patient with “raccoon eyes” and a midface fracture. Neurosurgical evaluation is important.
A CT scan of a midface fracture is essential for operative planning.
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 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.
A postoperative plain film X-ray shows the locations of the plates that have stabilized the midface fracture.
Mithani SK, St-Hilaire H, Brooke BS, Smith IM, Bluebond-Langner R, Rodriguez ED. Predictable patterns of intracranial and cervical spine injury in craniomaxillofacial trauma: analysis of 4786 patients. Plast Reconstr Surg
2009 Apr;123(4):1293–1301 [PubMed
]. (An extensive review of the epidemiology of fractures, which includes midface fractures and associated injuries)
Manson PN, Clark N, Robertson B et al. Subunit principles in midface fractures: the importance of sagittal buttresses, soft-tissue reductions, and sequencing treatment of segmental fractures. Plast Reconstr Surg
. (A definitive and well-organized review article that emphasizes treatment principles.)
- 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.
Subunit regions of the mandible.
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).
A Panorex plain film X-ray can be helpful in identifying mandible fractures.
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.
A reconstruction plate placed via an external incision on an angle fracture.
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.
Biller JA, Pletcher SD, Goldberg AN, Murr AH. Complications and the time to repair of mandible fractures. Laryngoscope
. (Analyzes the causes of complications as it relates to the timing of repair of mandible fractures, and it relates the incidence to several types of patient factors.)
Kaplan BA, Hoard MA, Park S et al. Immediate mobilization following fixation of mandible fractures: a prospective, randomized study. Laryngoscope
. (An excellent prospective study looking at the issues surrounding alternative plating techniques for fractures.)
Murr AH. Mandibular angle fractures and noncompression plating techniques. Arch Otolaryngol Head Neck Surg
[PubMed indexed for MEDLINE]. (Good summary of philosophies of managing various types of mandible fractures using several types of fixation approaches.)
Seemann R, Schicho K, Wutzl A, Koinig G, Poeschl WP, Krennmair G, Ewers R, Klug C. Complication rates in the operative treatment of mandibular angle fractures: a 10-year retrospective. J Oral Maxillofac Surg
2010 Mar;68(3):647-650 [PubMed
]. (Controversy exists with regard to using one or two monocortical miniplates on mandible angle fractures. This study shows no difference in the complication rates.)