Internal pterygoid muscle

Internal Pterygoid Muscle

The internal pterygoid muscle (shown in red) as seen from the medial side.

The Internal Pterygoid Muscle is one of the muscles of mastication, which are involved in the process of chewing. It is a thick, quadrilateral muscle located in the Infratemporal fossa of the skull.

Origin and Insertion

The internal pterygoid muscle originates from the pterygoid fossa of the sphenoid bone and the tuberosity of the maxilla. It inserts into the medial surface of the mandible, near the angle of the mandible.

Function

The internal pterygoid muscle acts to elevate the mandible, assisting in closing the mouth. It also contributes to protrusion of the mandible, moving the lower jaw forward. When acting unilaterally, it helps in the lateral (side-to-side) movements of the jaw.

Clinical Significance

Dysfunction of the internal pterygoid muscle can lead to Temporomandibular joint dysfunction, a condition characterized by pain and compromised movement of the jaw joint and the surrounding muscles.

See Also

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

References

• Gray, Henry. Anatomy of the Human Body. Philadelphia: Lea & Febiger, 1918; Bartleby.com, 2000. www.bartleby.com/107/.