The Effects of Discectomy on The Osteoarthrotic Temporomandibular Joint in Sheep

点击翻译按钮获取中文摘要

Bilateral temporomandibular joint (TMJ) osteoarthrosis was induced in four sheep and at three months a discectomy was performed on one joint, with the other being left as a control. The animals were sacrificed at six months. The specimens of the discectomized temporomandibular joint and control osteoarthrotic TMJ were radiologically compared.Morphological changes of osteophyte, erosion, flattening and sclerosis in the discectomized TMJ were greater than that in the control TMJ.Subcortical cyst formation was not observed in the radiograph on the both sides. The specimens were then histologically prepared and stained with H&E.All four control TMJ exhibited pathological changes consistent with osteoarthrosis, such as, disc perforation, osteophyte, and deformity ofthe condyle. The bone marrow fibrosis and subcortical cyst formation were extensive within the condyle in the control TMJ.The temporal articular surface was rather smooth. In the discectmized TMJ,the condyle was grossly deformed. However, the condylar bone marrow were mostly non-fibrotic and intact other than the immediate subarticular zone. Marked proliferation of the fibrous tissue was seen between the temporal and condylar articular surfaces, making the joint space narrow. In one joint, the joint space was completely obliterated by the loosely organized fibrous tissue. The short-term effects of discectomy on the osteoarthrotic TMJ were remodelling rather than degeneration. Postoperative mouth opening training is of clinical importance for prophylaxis of fibrous adhesion.