A Comparative Study of the Dentition and Temporomandibular Joint Anatomy and Histology Adult Dogs

Introduction: Dogs have been used for ages in surgical research, drug testing and in researching dog's disorders that are similar to human diseases. [1] It has been used as a model for many human conditions as cardiovascular research, diabetes mellitus, ulcerative colitis, open-heart surgery, organ transplantation, pharmacology and toxicology. Dogs are "diphyodont" having two sets of teeth, "28 deciduous teeth" being shed and replaced by a "42 permanent ones" set. Dogs have no deciduous precursor for the first premolar a single tooth erupts here at about 5 months. The temporomandibular joint is a group of anatomic structures that, with a special group of muscles, is responsible for the movement of the mandible during mastication. [5] It is classified as a hinge-sliding joint; it has a unique structure and function. It consists of the condylar process of the mandibular ramus, the mandibular fossa of the temporal bone, a thin articular disc, and a loose joint capsule, which is strengthened by a fibrous lateral ligament. TMJ is a cardinal feature that defines the class Mammalia and separates mammals from other vertebrates , its structure is interesting because of its constituent bones, the mandible and the squamous temporal, are intramembranous in origin. Thus, the tissue that covers each articulating surface is a secondary cartilage with a fibrous skin, derived from the periosteum