Head and neck muscles (chewing, facial, and throat muscles)

Inferior head of lateral pterygoid

Musculus pterygoideus lateralis, caput inferius

Origin

Outer surface of the lateral pterygoid plate (sphenoid bone)

Insertion

Pterygoid fovea of the condylar process of the mandible

Function

Protrusion and depression (mouth opening) of the mandible; unilateral contraction produces lateral (sideways) jaw movement

Innervation

Lateral pterygoid nerve (branch of CN V3)

Movement & chain

Together with the superior head, pulls the condyle and articular disc forward during mouth opening; alternating left-right contractions during chewing produce the grinding motion.

Palpation

Palpable intraorally posterior to the maxillary tuberosity along the anterior pterygoid plate.

Clinical

Often involved in temporomandibular dysfunction (TMD) and disc displacement of the jaw joint; tension can contribute to jaw pain and limited mouth opening.

Segmental innervation

Mandibular nerve (V3), motor.

In clinical practice

Primary jaw protruder; orofacial physical therapy and intraoral trigger point release for TMJ dysfunction and bruxism.

Region in the model

Head and neck muscles (chewing, facial, and throat muscles)