Radiology of maxillofacial trauma

There has been a rising incidence of maxillofacial injuries during the past decade as a result of an increasing number of assaults and motor vehicle accidents. The maxillofacial region is one of the most complex areas of the human body, and the radiographic imaging of this region becomes even more difficult in traumatized patients because of their clinical condition and their inability to cooperate. Imaging modalities used in the evaluation of the traumatized maxillofacial region include conventional (plain) films, tomography, panoramic radiography, computed tomography, three-dimensional computed tomography, DentaScan, and magnetic resonance imaging. Each modality is discussed with regard to technique, advantages, and disadvantages. Plain films and computed tomography, the modalities that are used most in evaluating maxillofacial structures, are discussed in more detail. The normal anatomy and radiologic features are presented for both of these modalities. Radiographic evaluation of maxillofacial injury begins with a knowledge of the direct and indirect radiographic signs of injury seen on most imaging modalities. Computed tomography also has allowed a method of classifying facial fractures that is based on the involvement of the facial buttresses or struts. Three horizontal, two coronal, and five sagittal oriented struts are described. Limited fractures are differentiated from transfacial fractures by the lack of involvement of the pterygoid plates in the limited fractures. Limited fractures also can be subclassified as solitary (fracture of a single strut) or complex (fractures of multiple struts). A portion of the orbit is involved in almost every form of facial fracture; therefore, evaluation of facial injuries should always include the orbital structures. Although both can occur simultaneously, orbital injuries can be divided into soft tissue and bony vault injuries. Similar to midface fractures, orbital fractures also can be classified as solitary (fracture involves a single wall) or complex (fracture involves more than one wall or a part of a midface fracture). Computed tomography is of great value in evaluating both forms of injury. Magnetic resonance imaging is becoming increasingly important in the evaluation of orbital soft tissue injuries. Classification of midface injuries includes the solitary strut fractures and the complex strut fractures. Solitary strut fractures include fractures of the nasal arch, zygomatic arch, and isolated sinus wall fractures. Complex strut fractures include the nasal complex fractures, zygomatic (tripod) and zygomaticomaxillary fractures, transfacial fractures (LeFort fractures), and facial smash fractures. Each fracture type and its radiographic appearance are discussed.(ABSTRACT TRUNCATED AT 400 WORDS)