Medial pterygoid

The medial pterygoid (Latin: musculus pterygoideus medialis) is a thick and quadrilateral-shaped muscle located in the infratemporal fossa of the skull. It is classified as one of the primary muscles of mastication. The medial pterygoid is composed of two heads - superficial (smaller) and deep (larger). This muscle provides movements of the mandible at the temporomandibular joint (TMJ).

Medial pterygoid, Muscles of mastication, Masticatory muscles, Head muscles, Medial pterygoid with the skull
Medial pterygoid by Anatomy Next
Medial pterygoid
Origin

Superficial head - maxillary tuberosity of the maxilla, pyramidal process of the palatine bone

Deep head - medial surface of the lateral pterygoid plate (sphenoid bone)

InsertionPterygoid tuberosity of the mandible, medial surface of the mandibular ramus
Action

Bilateral contractions - push the mandible forward, elevate the mandible

Unilateral contraction - pushes the mandible to the opposite side 

 Innervation Medial pterygoid nerve of the mandibular nerve
Blood supplyPterygoid branches of the maxillary, buccal and facial arteries

 

Origin

The superficial head of the medial pterygoid muscle originates from the maxillary tuberosity of the maxilla and pyramidal process of the palatine bone. The deep head of the muscle originates from the medial surface of the lateral pterygoid plate (of the sphenoid bone).

 

Insertion

The medial pterygoid inserts on the pterygoid tuberosity of the mandible and medial (inner) surface of the mandibular ramus.

Origin and insertion of medial pterygoid, Medial pterygoid
Origin and insertion of medial pterygoid by Anatomy Next

 

Action

Upon bilateral contractions, the medial pterygoid muscles push the mandible forward (protrude the mandible). By contracting on one side, the medial pterygoid pushes the mandible to the opposite side. This muscle also contributes to the elevation of the mandible, acting as a synergist to the temporalis and masseter.

Action of medial pterygoid, Function of medial pterygoid, Medial pterygoid
Action of medial pterygoid by Anatomy Next

 

Innervation

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

 

Blood supply

The medial pterygoid is provided with the arterial blood supply by the pterygoid branches arising from the maxillary, buccal (branch of the maxillary artery) and facial arteries