Effect of partial immobilization on reconstruction of ankylosis of the temporomandibular joint with an autogenous costochondral graft:an experimental study in sheep.

The purpose of this study was to show the effect of partial immobilization of a costochondral graft reconstruction of an ankylosed temporomandibular joint (TMJ) in five adult sheep. Ankylosis was induced in all right TMJs. At three months, a graft was inserted and partially immobilized. Three months after the second operation, four sheep were killed by an overdose with pentothal. One sheep was killed at one month because of infection. Functionally, the body weight, which decreases with ankylosis, did not recover after insertion of the graft and the range of jaw movements got worse. Histologically, the grafts were well attached to the mandibular rami in three of four joints. In one joint, the graft showed signs of resorption and a foreign body reaction. We conclude that, if the reconstructed joint is partially immobilized, then there will be a degree of reankylosis. There was also a high failure rate.