The zygomatic arch is predominantly formed by the zygomatic process of the temporal bone which articulates with the much smaller temporal process of the zygoma forming the arch. The temporalis muscle and coronoid process of the mandible lie beneath the arch and may become trapped in depressed fractures of the zygomatic arch.
Immediately below the infraorbital margin lies the infraorbital foramen, through which passes the infraorbital nerve (part of the maxillary division of the trigeminal nerve). The nerve’s location makes it very vulnerable to both direct injury, and involvement in ZMC fractures.