健康人髁突运动中心前伸和大张口轨迹特征的研究

目的 探讨髁突参考点选择不同对髁突运动轨迹形态的影响。方法 利用自行开发的髁突运动中心轨迹显示分析系统，分别以运动中心，终末绞链轴点作为参考点，研究30名健康人下颌前伸和大张口时髁突运动的矢状面轨迹。结果 运动中心位于终末绞链轴点的前上方，二者轨迹不同。健康人的髁突运动中心大张口迹轨，为一斜向前下方的平滑曲线，形态稳定，没有轨迹异常特征出现且左右侧对称，大张口运动轨迹起止点连线距离与前伸运动轨迹起止点连线距离的比值大于1．5。而终末绞链轴点大张口轨迹左右侧不对称，形态不稳定，会出现不规则形状，大张口运动轨起止点连线距离与前伸运动轨迹起止点连线距离的比值较小。结论 对于同一健康个体，运动中心轨迹较终末绞链轴点轨迹更恒定。

Trace features of the mandibular condylar kinematic center during jaw protrusive and open-closing movements in healthy subjects

Objective To investigate the variation in movement traces of different condylar reference points. Methods In 30 healthy subjects, mandibular movements were recorded during protrusion and open closing of the jaw. The kinematic center and terminal hinge axis point of the condyle were used as reference points. Results The kinematic center was located anteriorly and superiorly with respect to the terminal hinge axis point. The trace distance of the kinematic center was longer than that of the terminal hinge axis point of the condyle during opening. In contrast to differences in trace distances of the left and right condylar terminal hinge axis points, no such left right differences were found for the kinematic centers. The ratio between the distance of opening trace and the distance of protrusion trace of the kinematic center was above 1 5. Conclusions In comparison to the terminal hinge axis, the kinematic center shows fewer variations in the movement traces.