The superior pterygoid muscle has two heads, a superior and inferior head. The superior head originates from the infratemporal crest and inserts into the temporomandibular joint capsule and disc, while the inferior head originates from the pterygoid plate and inserts into the articular disc and fovea. Both heads of the superior pterygoid muscle function to depress and protrude the mandible, as well as move it from side to side, and are innervated by the pterygoid branch of the trigeminal nerve.

1. PTERYGOID MUSCLES

2. SUPERIOR PTERYGOID MUSCLE Short and thick Has two separate heads Superior head Inferior head Lies superiorly to Inferior Pterygoid Muscle

3. SUPERIOR HEAD Smaller of the two heads ORIGIN: Infratemporal crest of the greater wing of the sphenoid bone INSERTION: Articular capsule and articular disc of the temporomandibular joint

4. INFERIOR HEAD ORIGIN: Lateral surface of pterygoid plate INSERTION: Articular disc and pterygoid fovea

5. INFERIOR HEAD (ORIGIN)

6. ACTION Depress the mandible Protrude mandible Side to side movement of mandible

7. INNERVATION Pterygoid branch of the mandibular division of the trigeminal nerve