OBJECTIVE:The purpose of this experiment was to investigate the early histopathological changes that occur in the rabbit temporomandibular joint(TMJ) following surgical induction of ADD.METHODS:The left joints of 12 New Zealand rabbits were subjected to surgical induction of ADD,the right served as sham control.Four joints from two additional rabbits served as non-operated control.The TMJ were removed after 24h,1 week,2 weeks,3 weeks,4 weeks or 10 weeks and stained with HE.RESULTS:The results showed neovascularization,cell clustering and fibrillation of the displaced disk.Fibrosis and pseudo-disk formation were observed in bilaminar zone.The condyle and synovial membrane showed osteoarthritic changes.CONCLUSION:Surgical induction of ADD in the rabbit TMJ leads to histopathological changes in TMJ region similar to those described in human ADD,and the mechanical trauma resulting from ADD could lead to the changes in affected joints similar to those described for osteoarthritis.