Multicenter evaluation of temporomandibular joint Proplast-Teflon disk implant.

Seven oral and maxillofacial surgeons from all U.S. American Association of Oral and Maxillofacial Surgeons districts participated in a retrospective study of Proplast II Teflon interpositional implants that were placed after meniscectomy in 680 TMJs (465 patients) and followed from 6 to 76 months. At longest follow-up a relatively high number (85.9%) 584 of 680 implants were in place with an average weighted follow-up of nearly 32 months. Of these 584 joints, a very high number, 540, (92.4%) were asymptomatic, however, 224 asymptomatic and 25 symptomatic joints with the implants in place exhibited some degree of condyle resorption that included 45 with malocclusion. In the worst case scenario, if condylar resorption is indicative of a worn Proplast II Teflon interpositional implant, then 364 (54%) of the 680 implants may fail. Failure rates per year range from Vitek's reported 3% to an average 18% clinician report in the literature. Higher rates are reported by individual clinicians, and our recent in vitro wear tests of Proplast II Teflon interpositional implants suggest an in vivo service life of only 3 years. Because no one has reported follow-up beyond 5 years, the long term performance and survival of any of these implants is doubtful. Asymptomatic patients should be evaluated yearly with tomography, CT, or MRI. Symptomatic patients should be evaluated every 4 to 6 months. Implant removal should be recommended if occlusal changes or condyle/fossa articular bone changes are active past the time of expected remodeling from surgery. This report summarizes the success/failure incidence from the literature and makes recommendations on follow-up, removal, and repair surgery.