- The upper jaw is formed by two paired maxillae fused with the sutures. The upper jaw is not movable as the maxilla is a fixated part of the skull.
- The lower jaw is formed by an unpaired mandible. In contrast to the maxilla, the mandible is movable. The movements of the lower jaw happen at the temporomandibular joint at which the temporal bone and mandible articulate.
Also, the lower jaw is moved with the help of masticatory muscles. Both jaws contain teeth. All the mentioned structures are involved in digestion as they help to bite, chew, grind and hold digested food.