Muscle
Lateral pterygoid
Protrudes the jaw, opens the mouth
High-yield
Only muscle of mastication that OPENS the jaw (protraction/depression). "Lateral = Lowers." CN V3.
Overview
A two-headed muscle that protrudes the mandible and depresses it to open the mouth; the only muscle of mastication that opens the jaw.
Reference facts
- Origin
Greater wing of the sphenoid (upper head) and lateral pterygoid plate (lower head)
- Insertion
Neck of the mandible, articular disc, and capsule of the TMJ
- Action
Protrudes and depresses the mandible (opens the mouth); side-to-side grinding when unilateral
- Innervation
Nerve to lateral pterygoid from the mandibular division (CN V3)
- Blood supply
Pterygoid branches of the maxillary artery