The purpose of this study is to make a model of internal derangement (ID) and osteoarthritis (OA) by postero-superior displacement of the mandible in the rabbit temporomandibular joint (TMJ).
Sixteen Japanese white rabbits (8 months old) were subjected to traction of the mandibular ramus in the postero-superior direction unilaterally using elastic force and five rabbits were used as the control. The operations were performed without surgical invasion of the TMJ capsule. Temporomandibular joint tissue was removed after 4 weeks and Technovit and paraffin sections with or without decalcification were observed histologically.
In contrast to the control group, it showed anterior disc displacement, disc deformity, resorption of subchondral bone and osteophyte formation in the drawing side of the experimental group. Intra-articular fibrous adhesions were observed in both sides.
It is concluded that posterosuperior displacement of the mandible caused ID and OA in the rabbit TMJ. This model may contribute to the understanding of the etiology of human temporomadibular disorders (TMD).