Pterygoid muscle

Pterygoid muscles are two muscles located in the human skull. They are part of the muscles of mastication, which are responsible for movements of the jaw during chewing and speech. The pterygoid muscles consist of the lateral pterygoid muscle and the medial pterygoid muscle.

Anatomy

The pterygoid muscles, lateral view.

Lateral Pterygoid Muscle

The lateral pterygoid muscle is a short, thick muscle that has two heads. The upper head originates from the infratemporal surface and infratemporal crest of the greater wing of the sphenoid bone. The lower head originates from the lateral surface of the lateral pterygoid plate. The muscle inserts into the condylar process of the mandible and the articular disc of the temporomandibular joint.

Medial Pterygoid Muscle

The medial pterygoid muscle is a thick, quadrilateral muscle that originates from the medial surface of the lateral pterygoid plate, the pyramidal process of the palatine bone, and the tuberosity of the maxilla. It inserts into the medial surface of the angle and lower half of the ramus of the mandible.

Function

The lateral pterygoid muscle primarily acts to protrude the mandible, pulling the jaw forward. It also assists in the side-to-side grinding movements of the jaw. The medial pterygoid muscle acts to elevate the mandible, closing the jaw, and also contributes to the side-to-side grinding movements.

Clinical Significance

Dysfunction of the pterygoid muscles can lead to temporomandibular joint disorder, a condition characterized by pain and dysfunction of the jaw joint and the muscles controlling jaw movement.

See Also

• Muscles of mastication
• Temporomandibular joint
• Temporomandibular joint disorder