The temporalis muscle
is one of the muscles of mastication
It arises from the temporal fossa and the deep part of temporal fascia. It passes medial to the zygomatic arch and inserts onto the coronoid process of the mandible.
The temporalis muscle is covered by the temporal fascia, also known as the temporal aponeurosis.
The muscle is accessible on the temples, and can be seen and felt contracting while the jaw is clenching and unclenching.
As with the other muscles of mastication, control of the temporalis muscle comes from the third (mandibular) branch of the trigeminal nerve
. Specifically, the temporalis is innervated by the deep temporal nerves.
Contraction of the temporalis muscle elevates the mandible. The somewhat horizontal fibers of the posterior part of the muscle retract the mandible. In the human, the temporalis is the most powerful muscle of the body, with a record bite of 990 pounds observed in a man who suffered an epileptic seizure, which caused him to bite uncontrollably. This shattered most of his teeth. Were the teeth of a human able to withstand the sufficient pressure, a human could bite a hole into an automobile tire inflated to 65 psi
, chew up a cinder block, or bite through the rings or chain of a pair of handcuffs.
- - "Infratemporal Fossa: The Temporalis Muscle"