Gross anatomy of the craniomandibular joint and masticatory muscles of the dog.

The craniomandibular joint (CMJ) and masticatory muscles in 15 dogs (Canis familiaris) were dissected. The major structures were fossa, disc and condyle surrounded by a thin fibrous capsule. The horizontally orientated temporal fossa had a pronounced tubercle anteriorly. Posteriorly, a retroarticular process curved backwards. This fossa and process closely surrounded the condyle. The disc was thin. The cylindrically-shaped condyle was elongated in the medio-lateral direction, situated at right angles to the sagittal plane. The lateral pterygoid muscle was poorly developed; the temporalis was by far the largest masticatory muscle. These findings support the assumption that the movements of the canine mandible are mainly hinge-like. Furthermore, the canine CMJ differs in many respects from the corresponding anatomical structures in the domestic pig, as well as in man.