Emergency War Surgery NATO Handbook: Part IV: Regional Wounds and Injuries: Chapter XXIII: Maxillofacial Wounds and Injuries
United States Department of Defense
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Zygomaticomaxillary compound fractures. Fracture dislocations involving the zygomatic bone are the third most common fractures of the facial skeleton. The zygoma forms the major portion of the lateral and inferior rims of orbit, as well as a portion of the orbital floor. Because of its complex articulation and the importance of the soft tissue structures attached to it as well as those which it supports, early reduction of these fractures is highly desirable.
Fractures of the zygoma will usually displace the lateral palpebral ligament inferiorly, and are often accompanied by an orbital floor fracture which produces enophthalmos and diplopia. Diplopia may also be caused by entrapment of the inferior extraocular muscles which restrict upward and lateral motility of the eye. Additional signs of this injury may include loss of cheek bone prominence, limitation of mandibular excursion due to impingement upon the coronoid process of the mandible by the depressed zygoma or fractured and depressed zygomatic arch, subconjunctival hematoma, sensory disturbance over the distribution of the infraorbital nerve, and a palpable bony step-off at the inferior and lateral rims of the orbit and at the lateral wall of the maxilla intraorally, Bleeding from the nostril on the injured side is frequently seen. Nose blowing should be avoided.
Special attention should be given to the eye examination. Direct ocular injury is occasionally observed, particularly hyphema, dislocated lens, retinal detachment, and rupture of the globe, which are all ophthalmologic emergencies. Occasionally many of the findings associated with this and other midface fractures are obscured by swelling, edema, and ecchymosis. Thus, a knowledge of the fracture combined with a careful clinical examination and a well-directed radiographic survey are all essential to an appropriate diagnosis.
Definitive treatment of this injury depends upon the nature and severity of the fracture. In a straight-forward and non-comminuted type of fracture, an incision over the zygomaticomaxillary region at the lateral brow is made. An appropriate elevator is passed behind and beneath the zygoma and the fracture is elevated and reduced. If stable, no interosseous wiring is necessary. An unstable fracture may require wiring both the frontozygomatic and rim fracture. Orbital floor exploration frees muscle or fat entrapped inferiorly after realignment of the fractures. Intermittent release of pressure to intraorbital tissue is mandatory. Methylmethacrylate globe protectors are preferred. Large floor defects are repaired with an implant of suitable material. Except in grossly complicated cases, the use of packing or an antral balloon in the maxillary sinus is seldom required.
Midface Fractures. Fractures of the middle third of the face most frequently are described as Le Fort I (horizontal), Le Fort II (pyramidal), and Le Fort III (craniofacial dysjunction). All result in disturbances of the dental occlusion and share certain similarities upon clinical examination. The distinction between arid complexity of these injuries lie principally with the level within the midface at which fracture dislocation has occurred.
Le Fort I level fractures course through the lateral walls of the maxillary sinus, nasal fossa (including the nasal septum usually immediately superior to the floor of the nose), and the pterygoid process of the sphenoid bone posteriorly. The entire alveolar process of the maxilla containing the teeth, palate, floor of the maxillary sinuses arid nose are mobilized. Upon clinical manipulation, all of these structures are mobile and, depending upon the magnitude of displacement, there will be varying degrees of malocclusion of the teeth. The fracture fragment is most often one mobilized segment, but occasionally may be fractured sagittally or into several segments. When this occurs, the ideal method of treatment is with an individualized palatal splint, application of maxillary arid mandibular archbars, and intermaxillary fixation in centric dental occlusion. Sagittal and segmental fractures of the maxilla can be treated with intermaxillary fixation without palatal splints, and indeed on occasion must be so managed, but bony union and healing in malposition with significant malocclusion is a frequent sequella. Treatment for the Le Fort I level component rarely requires anything other than simple intermaxillary fixation. Blood accumulated in the maxillary sinus is ordinarily absorbed without incident. On rare occasions, additional suspension from a point above the level of the fracture may be required. A final inspection of the nasal septum is done and, if repositioning is required, it should be done at the time of primary repair.
The Le Fort II level fracture presents a more complex problem. Posteriorly, the fracture resembles that of the Le Fort I injury. Anteriorly it courses superiorly through the inferior rims of the orbits, often involving the orbital floors, then across the nasal bones separating them from the nasal process of the frontal bone. Frequently there is compounding into the anterior cranial fossa in the region of the cribriform process and crista galli of the ethmoid bone, with cerebrospinal rhinorrhea presenting as a part of the clinical findings. Clinical manipulation reveals mobility of the dentition and maxilla, which is transmitted to the infraorbital rims and to the junction of the nasal bones with the frontal bone. Periorbital ecchymosis arid edema are usually more profound and the face may appear to be elongated. The latter finding results when the pyramidal midface fracture fragment is displaced superiorly in its anterior portion and inferiorly in its posterior portion. This type of anteroposterior rotational displacement in a counterclockwise direction, when viewed from the patient's right side, results in premature posterior occlusion, anterior open bite, and the appearance of increased vertical facial height.
Treatment of the Le Fort II fracture consists of repositioning the midface fragment and stabilizing it to the intact mandible by intermaxillary fixation. Depending upon the nature of the fracture, open reduction and internal wire or bone plate fixation at the infraorbital rims, implantation of the orbital floors, and appropriate suspension from a stable point above the level of the fracture may be required. If it is necessary to pack the nose for hemostasis in the presence of cerebrospinal rhinorrhea, the packing should be removed as soon as possible as it is a significant promulgator of infection, placing the patient at increased risk of developing meningitis. When cerebrospinal rhinorrhea is not at issue, nasal packing for support of fractures may be done if desired. In any case, the combination of intermaxillary fixation and nasal packing is ordinarily a clear indication for tracheostomy.
The Le Fort III fracture separates the nasal bones from the frontal bone, courses downward and backward through the medial wall and floor of the orbit, across the lateral wall and rim of the orbit, and posteriorly through the maxilla, zygomatic arches, nasal septal-ethmoid region, and pterygoid process of the sphenoid bone, thus producing a dysjunction of the facial skeleton from that of the cranium. Many of the findings and treatment considerations previously described for the Le Fort II fracture are shared by this injury, except that manipulation of the maxilla results in mobility of the midface which is transmitted to the junction of the nasal and frontal bones and at the lateral rims of the orbits.
Nasal-Orbital Ethmoid Fracture. Direct blunt trauma to the nasal region may produce fracturing and dislocation of the nasal bones and septum of varying degrees of severity. With increasing force of trauma, the resulting injury is often much more extensive. In the nasal-orbital-ethmoid fracture, the nasal skeleton is separated from the frontal bone and driven posteriorly into the interorbital region occupied normally by the ethmoid air cells. The medial walls of the orbits become laterally splayed into the medial portion of the orbits. With lateral splaying of the medial wall, the medial canthal ligament is likewise displaced or on occasion severed free.
Some commonly associated clinical signs of this injury are widening of the nasal bridge, increased intercanthal distance (normally about 34 min in the adult white male), and an alteration in configuration of the medial palpebral fissure which has been described as "almond shaped." The injury is frequently accompanied by significant and sometimes massive edema and ecchymosis. Recognition and appreciation of the extent of the injury is therefore sometimes difficult. Evaluation by plain film radiography is often inadequate and more sophisticated studies are helpful, especially computerized axial and coronal tomography. In the final analysis, in most cases involving appreciable disruptions and displacements, accurate assessment and optimal repair are most often achieved by open exploration. The goals of treatment are:
Superior-Orbital-Fissure Syndrome. Although uncommon in injuries of the face, direct trauma and fracturing into the orbit may produce hemorrhaging and encystation of blood or an extension of the fracture into the superior orbital fissure, impairing or directly traumatizing the III, IV, and VI cranial nerves Which course through this fissure, resulting in ophthalmoplegia, ptosis of the lid, proptosis, and a fixed and dilated pupil. Sensory disturbances over the distribution of the ophthalmic division of the V cranial nerve, supratrochlear and supraorbital, complete the superior-orbital-fissure syndrome. In most instances, the treatment of choice is conservative. Ophthalmological consultation is indicated, and occasionally decompression is performed. Extension of the superior-orbital-fissure syndrome to include optic nerve involvement has been called the orbital-apex syndrome.
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