Temporalis muscle: anatomy, chewing and bruxism
- Muscle
- Nerve
- Highlighted area
Quick facts
- Origin
- Floor of the temporal fossa, up to the inferior temporal line, and the deep surface of the deep temporal fascia.
- Insertion
- Coronoid process and anterior border of the mandibular ramus, passing under the zygomatic arch.
- Action
- Elevates the mandible (closes the mouth); the posterior fibers, more horizontal, pull the mandible backward.
- Innervation
- Deep temporal nerves, from the mandibular division of the trigeminal nerve.
- Blood supply
- Deep temporal arteries (from the maxillary) and middle temporal artery (from the superficial temporal).
- Relevance in HOF
- Takes part in bruxism and tension headache and forms the deep plane of the temples.
The temporalis is a fan-shaped muscle that fills the temporal fossa, on the side of the head, and runs down under the zygomatic arch to the mandible. It is one of the main muscles of chewing: it closes the mouth and, with its posterior fibers, pulls the mandible backward. In HOF it matters for two reasons: it takes part in bruxism and it forms the deep plane of the temples.
Where is it and how is it built?
The muscle arises along the whole temporal fossa, up to the inferior temporal line, and from the deep surface of the deep temporal fascia that covers it. The fibers converge into a tendon that passes under the zygomatic arch and inserts on the coronoid process and the anterior border of the ramus of the mandible.
| Fiber group | Direction | Main action |
|---|---|---|
| Anterior | Almost vertical | Elevation of the mandible |
| Middle | Oblique | Elevation and stabilization |
| Posterior | Almost horizontal | Retrusion (pulling the mandible backward) |
Innervation comes from the deep temporal nerves, branches of the mandibular division of the trigeminal nerve. Blood supply comes from the deep temporal arteries, which run next to the bone, and from the middle temporal artery, which crosses the deep temporal fascia.
How does it fit into the layers of the temple?
From outside to inside, the temple has skin, subcutaneous tissue, temporoparietal fascia (where the superficial temporal artery runs), loose areolar tissue, deep temporal fascia, fat pad, the temporalis muscle and the periosteum. This organization, reviewed in layers of the face and in temporal fossa, explains why the temple has vessels in more than one plane.
Why does it matter in HOF?
- Bruxism and clenching: the temporalis works together with the masseter. Pain on the side of the head, tenderness on palpation and hypertrophy are possible findings. The topic is covered in botulinum toxin for bruxism.
- Temple contour: the volume of the muscle contributes to the lateral curve of the face. Reduced muscle activity can thin this contour.
- Temple filler: the muscle and the vessels around it define the planes considered in temple filler.
How does it show up in the assessment?
- Palpation with the teeth clenched: the muscle hardens on the side of the head, above the arch.
- Pain complaint: temporal headache, pain on waking and tooth wear suggest parafunction.
- Lateral contour: observe whether the temple is concave, flat or full, from the front and in profile.
- Dental exam: occlusion and the temporomandibular joint help separate aesthetics from dysfunction.
Also called: musculus temporalis, temporal muscle of mastication.
Frequently asked questions
Does the temporalis muscle take part in bruxism?
Yes. Together with the masseter, it is one of the main muscles that close the jaw and clench the teeth. In bruxism it can become hypertrophic or painful, with pain on the side of the head.
Can toxin in the temporalis muscle hollow the temple?
There are reports of a thinner temple contour when the muscle loses volume through reduced activity. That is why assessing the temporal contour is part of planning, at the discretion of the qualified professional.