Zygomaticomaxillary complex fracture

ReviewCTTrauma

Figure · click to enlarge

ZMC fracture components: lateral orbital rim, zygomatic arch, inferior orbital rim/floor, maxillary sinus walls

"Tetrapod" fracture separating the zygoma from its four articulations. Older term "tripod" omits the arch or the posterior maxillary wall depending on author.

Component	Where to look
Zygomaticofrontal / lateral orbital wall	Lateral orbital rim and zygomaticosphenoid suture
Zygomatic arch	Axial images at arch level; often 3 fracture lines
Inferior orbital rim and floor	Coronal reformats; check infraorbital canal
Zygomaticomaxillary buttress	Anterior and posterolateral maxillary sinus walls

Report

Displacement and rotation of the zygoma, depression of the malar eminence.
Orbital floor defect size, herniated fat or inferior rectus, orbital volume change.
Involvement of the infraorbital canal (V2 numbness).
Coronoid process impingement by a depressed arch (trismus).

Sources

Hopper RA, Salemy S, Sze RW. Diagnosis of midface fractures with CT: what the surgeon needs to know. Radiographics. 2006;26:783–793.PubMed ↗

Radessential summarizes published classification systems for practicing radiologists. Summaries are condensed; confirm details against the cited source before relying on them for patient care.