Muscles of the Temporomandibular Joint

The temporomandibular joint (TMJ) is responsible for jaw movements (phonation, chewing).

Joint : Mandibular fossa of temporal bone and condyle head of mandible.

Main Movements :

Occlusion – Contact of the teeth of the upper arch with the lower arch.

Protrusion – It is a forward movement (forward) as occurs in jaw protrusion.

Retrusion – It is a movement of retraction (backward) as occurs in the retrusion of the mandible.

1. TEMPORAL

Origin : External face of the temporal

Insertion : Coronoid process of the mandible and anterior aspect of the ramus of the mandible

Innervation : Temporal nerve (Mandibular branch of Trigeminal nerve – V Cranial nerve)

Action : Elevation (occlusion) and Retraction of the Mandible

2. MASSETER

Origin : Zygomatic arch

Insert :

Superficial Fasciculus : Angle and ramus of the mandible

Deep Fasciculus : Branch and coronoid process of the mandible

Innervation : Masseteric nerve (Mandibular branch of Trigeminal nerve – V Cranial nerve)

Action : Elevation (occlusion) of the Mandible

3. MEDIAL PTERYGOID

Origin : Medial surface of lateral plate of pterygoid process of sphenoid bone

Insertion : Medial surface of angle and ramus of mandible

Innervation : Medial pterygoid nerve (Mandibular branch of Trigeminal nerve – V cranial nerve)

Action : Elevation (occlusion) of the Mandible

4. SIDE PTERYGOID

Origin :

Superior Head : Greater wing of sphenoid

Inferior Head : Lateral face of the lateral plate of the pterygoid process of the sphenoid bone

Insert :

Superior Head : Anterior face of articular disc

Lower head : Condyle of the mandible

Innervation : Lateral pterygoid nerve (Mandibular branch of Trigeminal nerve – V cranial nerve)

Action : Opening of the Mouth and Protrusion of the Mandible. Move the jaw from side to side

ATM MUSCLES Masseter and Storm

Source: NETTER, Frank H.. Atlas of Human Anatomy. 2nd edition Porto Alegre: Artmed, 2000.

ATM MUSCLES Lateral and Medial Pterygoids – Lateral View

Source: NETTER, Frank H.. Atlas of Human Anatomy. 2nd edition Porto Alegre: Artmed, 2000.

ATM MUSCLES Lateral and Medial Pterygoids – Bottom View

Source: NETTER, Frank H.. Atlas of Human Anatomy. 2nd edition Porto Alegre: Artmed, 2000.