The lateral excursion refers to the side to side gliding movement of jaws that is unique to mammals. Lateral jaw movement is allowed by a temporomandibular joint which is a joint formed by the condylar process of the mandible and the mandibular fossa and articular tubercle of the temporal bone. This joint has features of both hinge and plane joints.
At the temporomandibular joint, the mandible is movable since the temporal bone is anchored by sutures to the other bones of the skull. During grinding of food, when the posterior teeth are pulled into occlusion, mandible exhibits side to side movement. This lateral jaw movement is observed in animals such as cows and horses during chewing of their food.
