Human Anatomy - Kotsan I. Ya. 2009

General overview of muscles responsible for movements of individual body parts
Head movements
Muscles responsible for movements of the mandible in the temporomandibular joints

The following movements are possible in the temporomandibular joints:

— elevation and depression of the Mandible;

— protrusion and retraction of the mandible;

— lateral Movements of the mandible (to the right and left).

Elevation of the mandible is performed by:

1) temporalis Muscles;

2) masseter muscles;

3) medial pterygoid muscles.

Depression of the mandible is performed by:

1) digastric muscles;

2) geniohyoid muscles;

3) mylohyoid muscles;

4) Infrahyoid muscles, which indirectly assist in lowering the mandible.

The action of all these muscles is complemented by the force of gravity acting on the mandible itself.

Protrusion of the mandible occurs through the simultaneous contraction of the right and left lateral pterygoid muscles.

Retraction of the mandible is brought about by the contraction of the posterior fibers of the temporalis muscles, aided by the digastric, stylohyoid, and geniohyoid muscles.

Lateral movement of the mandible is executed by the lateral pterygoid Muscle; contraction of this muscle on the right side shifts the jaw to the left, and vice versa.