mohammad alsehimy

ABSTRACT :
Several retrospective studies demonstrated that TMJ implants seemed to accelerate joint destruction as proved by FDA in 1990 . So , the current study was performed in an attempt to investigate the basic response of the tissue to failed TMJ proplast-teflon interpositional implants ( PTIPI ) . Thirteen patients underwent meniscectomy and disc replacement with Proplast-Teflon implants , and suffering from post-surgery pain , limited mouth opening , and joint noises that necessitated removal of the implants , were used for this study . It was shown that the PTIPI – induced lesions characteristically exhibited a large number of macrophages in the stroma of collagen – rich connective tissue . Animal experiments have shown also that PTIPI has the potential to induce destructive bony changes in operated joints based on reactive synovitis and massive infiltration of foreign body giant cells . Thus , it may be suggested that PTIPI is responsible for the destructive effect . However , mechanical stress seems important in the fragmentation of the implant and induction of the foreign body reaction too.