The effect of an intra-articular bone fragment in the genesis of temporomandibular joint ankylosis.

The aim of this study was to examine the effect of an intra-articular bone fragment on the genesis of temporomandibular joint (TMJ) ankylosis. Twenty-two adult sheep had a unilateral operation of removal of the temporal and condylar articular surfaces, plus discectomy with or without insertion of an intra-articular bone fragment. Functionally, radiologically, macroscopically and histologically, in the group with the intra-articular bone fragment, the joints showed more advanced ankylosis both at one and three months after the operation, as compared to the group with no intra-articular bone. This study shows that the bone fragment increases the extent of ankylosis in the sheep model. The clinical significance of the various experimental findings of this study and others in the same series is presented.