The temporalis is a large, fan-shaped muscle filling the temporal fossa on the side of the skull, its fibres converging through the zygomatic arch to the coronoid process of the mandible. It is the primary muscle for jaw closure and mandibular retraction, with its posterior horizontal fibres being the only muscle group that retrudes the mandible. The temporal headache associated with tension and TMJ dysfunction arises from the temporalis muscle and its fascial attachments.
| Origin | Temporal fossa of the skull and temporal fascia, over the full extent of the temporal lines from the frontal to the occipital bone |
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| Insertion | Coronoid process and anterior border of the ramus of the mandible |
| Nerve Supply | Deep temporal nerves (branches of the mandibular nerve, CN V3) |
| Blood Supply | Deep temporal arteries from the maxillary artery |
| Actions | Elevation of the mandible (all fibres); Retraction of the mandible (posterior fibres); Maintenance of the mandible in its rest position against gravity |
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The posterior fibres of the temporalis retract the mandible after protrusion, a function unique to this muscle among the masticatory group. This makes the posterior temporalis the critical muscle for normal occlusal return after forward jaw movement during biting.
Temporal arteritis (giant cell arteritis) affects the branches of the external carotid artery running through the temporalis and must be considered when new-onset temporal headache occurs in a patient over 50. Temporomandibular joint dysfunction frequently involves temporalis tenderness and referral of pain from its trigger points into the upper teeth and the temporal region. Temporal fascia is harvested as a surgical graft for tympanoplasty, dural repair, and joint reconstruction.
The temporalis is palpable over the entire temporal fossa from the hairline to the zygomatic arch, becoming visibly contracted and hard during forceful jaw clenching. Tenderness in this region during palpation is a key finding in TMJ dysfunction assessment.
Trigger points in the temporalis producing temporal headache and upper tooth pain referral patterns associated with jaw clenching and bruxism, managed with splints, trigger point release, and stress management.
