Zygomaticomaxillary complex fracture

Zygomaticomaxillary complex (ZMC) fractures, also known as a tripod, tetrapod, quadripod, malar or trimalar fractures, are seen in the setting of traumatic injury to the face. They comprise fractures of the:

  • zygomatic arch
  • inferior orbital rim, and anterior and posterior maxillary sinus walls
  • lateral orbital rim

They can account for ~40% of midface fractures. They are the second most common facial bone fracture after nasal bone fractures

The fracture complex results from a direct blow to the malar eminence and results in three distinct fracture components that disrupt the anchoring of the zygoma. Additionally, the fracture components may result in impingement of the temporalis muscle, trismus (difficulty with mastication) and may compromise the infraorbital foramen/nerve resulting in hypo-aesthesia within its sensory distribution.

On radiographic evaluation, typically with dedicated CT imaging with multiplanar reformats, the following three fracture components are generally identified:

If needed, closed or open reduction methods can be performed with the goal of treatment being preservation of normal facial structure, sensory function, globe position and mastication functionality.

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Article information

rID: 11114
Synonyms or Alternate Spellings:
  • Tripod fracture
  • Malar fracture
  • Trimalar fracture
  • Zygomaticomaxillary complex fractures
  • Zygomatico-maxillary complex fracture
  • Tripod fractures
  • Malar fractures
  • Trimalar fractures
  • ZMC fracture

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