Histological changes in the temporomandibular joint in rabbits depending on the extent of mandibular lengthening by osteodistraction.

We studied the histological changes in the temporomandibular joint (TMJ) after unilateral mandibular distraction osteogenesis in rabbits. Eight rabbits were used, two of which served as controls and the other six had distraction of the left mandibular body after a latency period of 7 days at a rate of 0.5mm a day for a total of 2mm (n = 2), 3.5mm (n = 2), and 5mm (n = 2) of distraction. After a 14-day consolidation period, TMJs from both sides were harvested and prepared for histological examination under an optical microscope using haematoxylin and eosin stain. We found no degenerative or inflammatory changes in either TMJ in any of the groups. Endochondral ossification in the condyle was greater on the opposite side in the experimental group than in the condyles of the control group. Endochondral ossification was active in the 3.5-mm group.