Pterygoid

Pterygoid refers to two muscles of mastication, or chewing, in the upper jaw (maxilla) and palate. The term "pterygoid" is derived from the Greek words for "wing" and "shape," due to the wing-like shape of the pterygoid process of the sphenoid bone from which these muscles originate.

Anatomy

The pterygoid muscles consist of the lateral pterygoid and the medial pterygoid. Both muscles are involved in moving the mandible, the lower jawbone, during chewing and speaking.

Lateral Pterygoid

The lateral pterygoid has two heads: the upper, or superior, head and the lower, or inferior, head. The superior head originates from the infratemporal surface and infratemporal crest of the greater wing of the sphenoid bone. The inferior head originates from the lateral surface of the lateral pterygoid plate of the sphenoid bone.

Medial Pterygoid

The medial pterygoid also has two heads: the deep head and the superficial head. The deep head originates from the medial surface of the lateral pterygoid plate and the pyramidal process of the palatine bone. The superficial head originates from the maxillary tuberosity and the pyramidal process of the palatine bone.

Function

The pterygoid muscles are primarily involved in chewing and speaking. The lateral pterygoid is responsible for opening the mouth and moving the mandible forward, while the medial pterygoid assists in closing the mouth and moving the mandible sideways.

Clinical Significance

Dysfunction or injury to the pterygoid muscles can result in temporomandibular joint dysfunction (TMJ), a condition that can cause pain and difficulty in moving the jaw.

See Also

• Muscles of mastication
• Sphenoid bone
• Mandible
• Temporomandibular joint dysfunction