Abstract: | Dacron-reinforced silicone is widely used as disk-replacement implant material in the temporomandibular joint. A retrospective radiographic analysis was undertaken in a series of thirty-two patients on whom diskectomy had been performed. Twenty patients had received temporary silicone implants, whereas twelve patients had surgery without disk-replacement implants. Six of the patients with implants had destructive lesions of the mandibular condyles at follow-up examinations, but no such lesions were seen in any of the patients who had surgery without implants. Histologic analysis of material removed from one patient who had a second operation showed multiple particles of foreign material surrounded by focally marked inflammatory reaction with foreign body granulomas. The underlying cartilage and bone showed focal resorption and bone destruction. Electron microscopy combined with energy-dispersive x-ray microanalysis showed that the foreign material contained silicone. It was concluded that the radiographically observed destructive lesions of the mandibular condyle may be a sign of a reactive synovitis induced by silicone particles abraded from the silicone implant. |