Head and Neck ImagingZygomatic fractures
Direct
trauma to the region of the zygoma is common. Zygomatic fractures are the second most common of
facial fractures, after nasal bone fractures. In isolated zygomatic arch fractures, the displacement of the fragments is often medial and downwards, reflecting the impact of the blow. Such fragments may impinge on the coronoid process of the mandible and interfere with the movement of the lower jaw. The zygoma can become detached from the surrounding facial skeleton, and be displaced in several directions. This kind of
fracture is known as a trimalar or tripod
fracture. Although these fractures can be diagnosed on conventional
X-ray,
CT very clearly demonstrates the displacement of the zygoma (
Le Fort fracture (VI:2), Fig. 1). Extension of a zygomatic
fracture to the orbital floor, with involvement of the infraorbital nerve canal, is common.
RH