Definition

Injuries to the zygoma and the surrounding facial bones are confusingly referred to by a number of different terms including:

• Malar fracture
• Tripod fracture
• Zygomatic complex fracture
• Zygomaticomaxillary complex fracture

All these terms refer to injuries of the zygoma with, in most cases, involvement of the maxilla or temporal bone. The sutures connecting the zygoma to adjacent bones may also be disrupted. Whilst it is important to delineate the individual components of a facial injury, in most instances this can only be done accurately by CT scan at a later stage.

How can we avoid confusion when describing these injuries in the ED?

For clinical clarity in the ED, it is suggested that the majority of injuries involving the zygoma and surrounding bones are either referred to as:

• Zygomatic arch fractures, i.e. fractures predominantly affecting the zygomatic arch, or
• Zygomaticomaxillary complex (ZMC) injuries, i.e. those fractures mainly involving the zygoma, maxilla and/or the orbital rim

Which injuries are not covered by these terms and can be separately identified in the ED?

Other important midface fractures which may be differentiated clinically in the ED are:

• Nasal and nasoethmoidal fractures
• Orbital floor fractures
• Le Fort type fractures

Learning bite

Confusingly, many terms exist for fractures to the zygoma and surrounding bones. For clarity the emergency physician (EP) should refer to injuries either to the zygomatic arch or the zygomaticomaxillary complex (ZMC).