Temporal muscle

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Temporal muscle
Gray382.png
The Temporalis; the zygomatic arch and Masseter have been removed.
Latin Musculus temporalis
Origin Temporal lines on the parietal bone of the skull and the superior temporal surface of the sphenoid bone.
Insertion Coronoid process of the mandible.
Artery Deep temporal arteries
Nerve Deep temporal nerves, branch(es) of the anterior division of the mandibular nerve (V3)
Actions Elevation and retraction of mandible
Antagonist Platysma muscle
TA A04.1.04.005
FMA FMA:49006
Anatomical terms of muscle

The temporal muscle, also known as the temporalis, is one of the muscles of mastication. It is a broad, fan-shaped muscle on each side of the head that fills the temporal fossa, superior to the zygomatic arch so it covers much of the temporal bone.[1]

Structure[edit]

In humans, 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, with its insertion extending into the retromolar fossa posterior to the most distal mandibular molar.[2] In other mammals, the muscle usually spans the dorsal part of the skull all the way up to the medial line. There, it may be attached to a sagittal crest, as can be seen in early hominins like Paranthropus aethiopicus.

The temporal 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.

Development[edit]

The temporalis is derived from the first pharyngeal arch in development.

Innervation[edit]

As with the other muscles of mastication, control of the temporal muscle comes from the third (mandibular) branch of the trigeminal nerve. Specifically, the muscle is innervated by the deep temporal nerves.

Blood supply[edit]

The muscle receives its blood supply from the deep temporal arteries which anastomose with the middle temporal artery.

Function[edit]

If the entire muscle contracts,the main action is to elevate the mandible, raising the lower jaw. Elevation of the mandible occurs during the closing of the jaws. If only the posterior part contracts, the muscle moves the lower jaw backward. Moving the lower jaw backward causes retraction of the mandible. Retraction of the jaw often accompanies the closing of the jaws.[1]

When lower dentures are fitted, they should not extend into the retromolar fossa to prevent trauma of the mucosa due to the contraction of the temporalis muscle.[2]

Additional images[edit]

References[edit]

  1. ^ a b Illustrated Anatomy of the Head and Neck, Fehrenbach and Herring, Elsevier, 2012, page 98
  2. ^ a b Human Anatomy, Jacobs, Elsevier, 2008, page 194

External links[edit]