Lateral pterygoid muscles

Lateral pterygoid muscle
File:Lateral pterygoid muscle.png Lateral pterygoid muscle (highlighted in red)
Details
Origin	Greater wing of sphenoid, Lateral pterygoid plate
Insertion	Condyloid process of the mandible
Artery	Pterygoid venous plexus
Nerve	Lateral pterygoid nerve from the mandibular nerve
Actions	Depresses and protrudes the mandible, moves it from side to side
Antagonist	Masseter muscle, Temporalis muscle
Identifiers
Latin	Musculus pterygoideus lateralis
TA98
TH	{{#property:P1694}}
TE	{{#property:P1693}}
FMA	{{#property:P1402}}
Anatomical terms of muscle

The lateral pterygoid muscle (or external pterygoid muscle) is a muscle of mastication with two heads. It lies superior to the medial pterygoid muscle and is one of the muscles that assist in the movement of the mandible.

Structure

The lateral pterygoid muscle has two heads: the superior head and the inferior head.

Superior head

The superior head originates from the greater wing of the sphenoid bone. It inserts into the articular disc and fibrous capsule of the temporomandibular joint.

Inferior head

The inferior head originates from the lateral surface of the lateral pterygoid plate of the sphenoid bone. It inserts into the pterygoid fovea on the neck of the condyloid process of the mandible.

Innervation

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

Blood supply

The muscle receives its blood supply from the pterygoid venous plexus.

Function

The primary function of the lateral pterygoid muscle is to depress and protrude the mandible. It also assists in the side-to-side movement of the mandible, which is essential for mastication (chewing).

Clinical significance

Dysfunction of the lateral pterygoid muscle can contribute to temporomandibular joint disorder (TMD), which can cause pain and difficulty in moving the jaw.

See also

• Medial pterygoid muscle
• Temporomandibular joint
• Mastication
• Mandibular nerve
• Trigeminal nerve