Diagnosis of midface fractures with CT: what the surgeon needs to know.

Computed tomography is commonly used to evaluate patients with blunt facial trauma. With the high definition of the current scanners, even small fractures of the facial skeleton can be visualized. In complex midface injuries, it can be difficult for the radiologist to know which fractures are important to point out to the surgeon. An understanding of the anatomically relevant and surgically accessible craniofacial buttresses is critical for management of these injuries. Naso-orbitoethmoid fractures are classified according to the degree of injury to the medial canthal attachment. If the nasofrontal ducts are disrupted, surgical obliteration of the frontal sinus is needed to prevent formation of a mucocele. Displaced fractures of the zygomaticomaxillary complex often increase orbital volume due to angulation of the lateral orbital wall at the zygomaticosphenoid suture. If the zygomatic arch is severely comminuted or angulated, surgical exposure is indicated. In orbital fractures, the position and shape of the medial and inferior rectus muscles can indicate whether entrapment and diplopia are likely. Pediatric "trapdoor" orbital fractures and fractures of the orbital apex associated with decreasing vision represent surgical emergencies. Le Fort fractures involve disruption of the pterygoid plates from the posterior maxilla; any combination of Le Fort I, II, and III patterns can occur.