Lateral pterygoid

The lateral pterygoid (Latin: musculus pterygoideus lateralis) is a thick and short triangular-shaped muscle located in the infratemporal fossa of the skull. It is classified as one of the primary muscles of mastication. The lateral pterygoid muscle is composed of two heads - superior and inferior.

Origin

The superior head of the lateral pterygoid originates from the infratemporal surface and crest of the greater wing of the sphenoid. The inferior head of this muscle originates from the lateral surface of the lateral pterygoid plate (of the sphenoid bone).

Insertion

The lateral pterygoid inserts on the pterygoid fovea of the mandible. The pterygoid fovea is located on the condylar process of the mentioned bone.

Action

Upon bilateral contractions, the lateral pterygoid muscles push the mandible forward (protrude the mandible). By contracting on one side, the activated lateral pterygoid muscle pushes the mandible to the opposite side. The lateral pterygoid muscles depress the mandible.

Innervation

The lateral pterygoid muscle is innervated by the lateral pterygoid nerve, a branch of the mandibular division of the trigeminal nerve (CN V3).

Blood supply

The lateral pterygoid is provided with the arterial blood supply by the pterygoid branches of the maxillary artery and ascending palatine branch of the facial artery.