Jaw Muscles

Question 1

Lateral Pterygoid

Answer 1

Origin:
Superior head: infratemporal surface of greater wing of sphenoid
Inferior head: lateral pterygoid plate

Insertion: pterygoid fovea, capsule of temporomandibular joint, and articular disc

Innervation: mandibular nerve

Blood Supply: muscular branches of maxillary artery

Action:

bilaterally: protrude mandible
unilaterally: produces side-to-side grinding

Question 2

Medial Pterygoid

Answer 2

Origin: medial surface of lateral plate of pterygoid, pyramidal process of palatine bone, and maxillary tuberosity

Insertion: medial surface of ramus and angle of mandible inferior to mandibular foramen

Innervation: mandibular nerve (nerve to medial pterygoid)

Blood Supply: facial and maxillary arteries

Action:

bilaterally: protrude and elevate mandible
unilaterally: produces side-to-side movements