The four classical muscles of mastication elevate the mandible (closing the jaw) and move it forward/backward and laterally, facilitating biting and chewing.

The muscles are: In humans, the mandible, or lower jaw, is connected to the temporal bone of the skull via the temporomandibular joint.

The muscles of mastication originate on the skull and insert into the mandible, thereby allowing for jaw movements during contraction.

Each of these primary muscles of mastication is paired, with each side of the mandible possessing one of the four.

The muscles of facial expression, on the other hand, are derived from the second pharyngeal arch.