Shimahara M, Ono K, Hashiguchi N
Department of Oral Surgery, Osaka Medical College, Japan.
Bull Osaka Med Coll. 1990 Nov;36(1-2):79-92.
Abnormal mandibular movement continues to occur when fracture of the mandibular process has resulted in abnormal occlusion or abnormal mandibular movement. However, what changes might occur in the temporomandibular joint have not yet been fully clarified. In the present study, a fracture of the condylar process was experimentally induced in rats, and the resulting bone ends were wired in place. That is to say, the resulting displacement was fixed permanently. Histological studies were made on the changes of the temporomandibular joint at the postoperative third month in those rats which demonstrated abnormal occlusion and abnormal mandibular movement. Lack of uniformity of the fibrous layer and a shallowing of the mandibular fossa; proliferation of the fibrous connective tissue and reduction in size of the superior and inferior articular cavity; tylosis and irregularity in the articular disc; deformation and tylosis of the fibrous layer of the articular cartilage, tendency of the layer structure in the articular cartilage to disappear, and some effect on cartilaginous ossification in the condyle; flattening of the condyle and thinning of the layer structure in the condylar articular cartilage in the unaffected side of the mandibular joint. These changes were observed to be more marked as the displacement and occlusal abnormality of the mandible intensified, showing no morphological adaptation of the temporomandibular joint.
当下颌突骨折导致咬合异常或下颌运动异常时，异常的下颌运动仍会持续发生。然而，颞下颌关节可能发生的变化尚未完全阐明。在本研究中，通过实验诱导大鼠髁突骨折，并将骨折后的骨端用金属丝固定在位。也就是说，所产生的移位被永久固定。对那些表现出咬合异常和下颌运动异常的大鼠术后第三个月的颞下颌关节变化进行了组织学研究。观察到纤维层不均匀以及下颌窝变浅；纤维结缔组织增生，上、下关节腔变小；关节盘出现角化和不规则；关节软骨纤维层变形和角化，关节软骨层结构有消失的趋势，并且对髁突软骨内成骨有一定影响；下颌关节未受影响侧的髁突变平，髁突关节软骨层结构变薄。随着下颌骨移位和咬合异常加剧，这些变化更为明显，表明颞下颌关节没有形态学适应。
