The zygomatic arch
is formed by the zygomatic process of temporal bone
(a bone extending forward from the side of the skull
, over the opening of the ear) and the temporal process of the zygomatic bone
(the side of the cheekbone), the two being united by an oblique suture; the tendon of the Temporalis
passes medial to the arch to gain insertion into the coronoid process
of the mandible
The zygomatic process of the temporal arises by two roots:
- an anterior, directed inward in front of the mandibular fossa, where it expands to form the articular tubercle.
- a posterior, which runs backward above the external acoustic meatus and is continuous with the supramastoid crest.
The upper border of the arch gives attachment to the temporal fascia; the lower border and medial surface give origin to the Masseter.
The zygomatic arch is significant in evolutionary biology, as it is part of the structures derived from the ancestral single temporal fenestra of the synapsid ancestor of mammals.