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.