Anatomy and Function of the Muscles of Mastication

Nerve Supply to Muscles of Mastication

The muscles of mastication are essential for chewing and involve four primary muscles: the masseter, temporalis, medial pterygoid, and lateral pterygoid. These muscles work in coordination to facilitate jaw movement.

Innervation

All muscles of mastication are innervated by the mandibular branch of the trigeminal nerve (cranial nerve V). This nerve provides both motor and sensory innervation.

Functional Role

• Masseter: Elevates the mandible for forceful chewing.
• Temporalis: Retracts and elevates the mandible.
• Medial Pterygoid: Assists in elevation and side-to-side movements.
• Lateral Pterygoid: Primarily responsible for depression and protrusion of the mandible.

Clinical Relevance

Dysfunction of these muscles can lead to temporomandibular joint disorders, difficulty chewing, and pain in the jaw region.