The zygomatic arch or cheek bone is formed by the zygomatic process of temporal bone

Zygomatic process of temporal bone

The zygomatic process of the temporal bone is a long, arched process projecting from the lower part of the squamous portion of the temporal bone...

 (a bone extending forward from the side of the skull

Human skull

The human skull is a bony structure, skeleton, that is in the human head and which supports the structures of the face and forms a cavity for the brain.In humans, the adult skull is normally made up of 22 bones...

, over the opening of the ear) and the temporal process of the zygomatic bone

Zygomatic bone

The zygomatic bone is a paired bone of the human skull. It articulates with the maxilla, the temporal bone, the sphenoid bone and the frontal bone. The zygomatic is homologous to the jugal bone of other tetrapods...

 (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

Coronoid process

The Coronoid process can refer to:* The coronoid process of the mandible, part of the ramus mandibulae of the mandible...

 of the mandible.

The term zygomatic derives from the Greek Ζυγόμα zygoma meaning "yoke". The zygomatic arch is occasionally referred to as the zygoma

Zygoma

The term zygoma generally refers to the zygomatic bone, a bone of the human skull commonly referred to as the cheekbone or malar bone, but it may also refer to:...

, but this term usually refers to the zygomatic bone or occasionally the zygomatic process

Zygomatic process

Zygomatic process is a protrusion from the rest of the skull, like the bumper of a car. Most of it belongs to the zygomatic bone, and could therefore be called the zygomatic process of the zygomatic bone...

.

The zygomatic process of the temporal arises by two roots:

• an anterior, directed inward in front of the mandibular fossa
  Mandibular fossa
  The mandibular fossa is the depression in the temporal bone that articulates with the mandibular condyle. In the temporal bone, the mandibular fossa is bounded, in front, by the articular tubercle; behind, by the tympanic part of the bone, which separates it from the external acoustic meatus; it is...
  
  , 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

Temporal fascia

The temporal fascia covers the Temporalis muscle.It is a strong, fibrous investment, covered, laterally, by the Auricularis anterior and superior, by the galea aponeurotica, and by part of the Orbicularis oculi....

; 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

Synapsid

Synapsids are a group of animals that includes mammals and everything more closely related to mammals than to other living amniotes. They are easily separated from other amniotes by having an opening low in the skull roof behind each eye, leaving a bony arch beneath each, accounting for their name...

 ancestor of mammal

Mammal

Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

s.

External links

• Diagram at unc.edu