Comparison between human and rat TMJ: anatomic and histopathologic features.
OBJECTIVE
To describe and evaluate normal rat temporomandibular joints from anatomic and histopathologic point of view and make a comparison between this joint in rats and humans.


METHODS
Twelve male adult Wistar rats (12 same side joints) were used in this procedure. The following anatomical structures were histologically evaluated in a qualitative fashion: condyle, disc, temporal bone, retrodiscal tissue and synovia. The macroscopical and microscopic study of the human TMJ was based on the current literature.


RESULTS
The TMJ is surrounded by a thin capsule, consisting of fibrous tissue, and a synovial lining. The mandibular angle has a prominent shape. The glenoid fossa is flat, with no eminences. Histologically, the TMJ is composed of different tissues that comprise the mandibular head, mandibular fossa and fibrocartilaginous disc. A layer of hyaline cartilage covers the articulating cortical condyle and temporal bone.


CONCLUSIONS
Morphologically and histologically, the articular structure of rats is, on the whole, similar to that of humans. In these animals there is no articular eminence.
Porto
Gabriela Granja
GG
Department of Oral and Maxillofacial Surgery, UPE, Recife, PE, Brazil.
Vasconcelos
Belmiro Cavalcanti do Egito
BC
Andrade
Emanuel Sávio de Souza
ES
Silva-Junior
Valdemiro Amaro
VA
D000717:Anatomy, Comparative; D000818:Animals; D006801:Humans; D008297:Male; D008335:Mandibular Condyle / Q000033:anatomy & histology; D023421:Models, Animal; D051381:Rats; D017208:Rats, Wistar; D013701:Temporal Bone / Q000033:anatomy & histology; D013704:Temporomandibular Joint / Q000033:anatomy & histology* / Q000166:cytology*; D019224:Temporomandibular Joint Disc / Q000033:anatomy & histology