Corpus: Temporal muscle

The temporal muscle is a skeletal muscle that is part of the superficial muscles involved in mastication (chewing).

The temporal muscle originates over a large area on the outer surface of the temporal bone, specifically from the temporal fascia between the inferior temporal line and the infratemporal crest. It fills both the temporal and infratemporal fossae. The anterior portions of the muscle arise from the zygomatic and frontal bones as well as the greater wing of the sphenoid bone. The posterior portions originate from the parietal bone near the lambdoid suture. Additionally, a deep medial section of the muscle originates at the base of the skull between the infratemporal crest and the entrance to the pterygopalatine fossa. The entire muscle is covered by a strong fascia (temporal fascia), which also serves as part of the muscle's origin.

The extensive muscle fibers of the temporal muscle converge into a strong tendon that attaches to the coronoid process and the temporal crest of the mandible. Additionally, some tendon fibers radiate into the fascia of the buccinator muscle, known as the buccotemporal fascia.

The temporal muscle is innervated by the deep temporal nerves, which arise from the mandibular nerve (cranial nerve V3).

The temporal muscle, along with the masseter and medial pterygoid muscles, plays a key role in closing the jaw (adduction), contributing to mouth closure. The deep medial sections of the temporal muscle help to pull the lower jaw forward (protrusion), while the posterior sections are responsible for pulling it backward (retrusion). The temporal muscle is the strongest individual muscle involved in jaw closure.

When the temporal muscle contracts unilaterally, it causes the mandibular head on the opposite side to shift forward, which assists in the grinding movement of the jaw during chewing.