Head and neck muscles (chewing, facial, and throat muscles)
Superior head of lateral pterygoid
Musculus pterygoideus lateralis, caput superius
- Origin
- Infratemporal crest and the infratemporal surface of the greater wing of the sphenoid bone
- Insertion
- Joint capsule and articular disc of the temporomandibular joint, with a small part on the pterygoid fovea of the mandibular neck
- Function
- Stabilizes the articular disc during jaw closing and assists coordinated chewing movements (unlike the inferior head, which mainly produces protrusion)
- Innervation
- Lateral pterygoid nerve, branch of the mandibular nerve (V3, trigeminal nerve)
- Movement & chain
- Unlike the inferior head (which produces protrusion by contracting during mouth opening), the superior head is active during jaw closing and stabilizes the articular disc.
- Palpation
- Difficult to isolate by palpation; inserts directly into the TMJ articular disc and capsule.
- Clinical
- Dysfunction of this muscle is associated with clicking and pain in the temporomandibular joint (temporomandibular dysfunction).
- Segmental innervation
- Motor via the trigeminal nerve (V3); no spinal segment.
- In clinical practice
- Stabilizes the TMJ disc during power closing; hyperactivity causes anterior disc displacement with reduction (painful jaw clicking).
- Region in the model
- Head and neck muscles (chewing, facial, and throat muscles)