Facial fracture

Conventional radiography remains the cornerstone of the radiological evaluation of the traumatized maxillofacial skeleton. This is especially true for fractures caused by the impact of low-energy objects, such as a blow to the nose. Direct signs of facial fracture are interruption of a cortical line, or an abnormal linear density, caused by the turning on edge of a fragment of bone normally lying more or less parallel to the film. Indirect signs are soft tissue swelling, sinusal airfluid level head and neck or complete opacification. Subcutaneous, periocular or intracranial air is diagnostic of a fracture through an aerated cavity.

Nasal fractures

Isolated nasal fractures are very common and do not in fact require a radiographic examination, as they can be assessed by clinical examination. Films are usually taken for medicolegal reasons.

Orbital fractures

The bony orbital walls are commonly involved in more complex facial fractures. When the eye is hit and pushed back in the orbit, the thin orbital floor may be selectively fractured (see blow out fracture).

Frontal and ethmoidal fractures

Frontal fractures are the result of a direct trauma or extension of a calvarial (skull) fracture. A fracture of the posterior wall of the frontal sinus may be complicated by cerebrospinal fluid leak, a pneumocele, meningitis or contusion to the frontal brain parenchyma. Such a posterior wall fracture may be difficult to visualize on conventional radiographs. CT is very useful in demonstrating these fractures (Fig.1).

If a small object hits the nasal bridge with higher energy, a naso-orbital or nasoethmoidal fracture may result: the nasal pyramid is severely fractured and forced posteriorly in between the two orbits (Fig.2), producing hypertelorism and comminution of the ethmoidal complex. The medial eye structures (the medial canthal ligament and lacrimal apparatus) are often injured. Often there are also fractures of the floor of the anterior cranial fossa, with tearing of the dura providing a pathway for cerebrospinal fluid rhinorrhoea (see cerebrospinal fluid leak).

Zygomatic fractures

Fractures of the zygomatic arch are commonly seen. The zygoma can become detached from the surrounding facial skeleton, and be displaced in several directions.

Complex maxillofacial fractures

These are usually classified according to Le Fort (see Le Fort fractures). In a Le Fort I fracture there is detachment of the upper jaw from the remainder of the maxillofacial skeleton, while in a Le Fort II fracture a pyramidal fracture configuration is present. A Le Fort III fracture is characterized by separation of the entire facial skeleton from the skull base. Also, see dishface deformity.

Mandibular fractures

Plain films and panoramic views are usually adequate and cost-effective means of evaluating solitary mandibular injuries, such as mandibular condyle and neck fractures. Also, see empty glenoid fossa sign.

The mandible can be considered as a bony ring: in the case of a major impact, it will very often fracture in two places: one fracture at the location of the impact (symphysis) and a reciprocal fracture where the force is dissipated through the mandible (condylar neck) (Fig.3). A ma A mandibular symphysial fracture can be considered as an open fracture as it runs through the teeth-bearing region of the lower jaw; posterior displacement of the mandible is possible due to traction of the digastric muscle and geniohyoideus muscle, and compromise of the oropharyngeal airway is possible.

RH