Abstract:

Occlusion contact is necessary for occlusion function. Occlusion contact derives from muscle contraction which is motivated centrally and modified peripherally. Occlusal contact adjust the pattern of masticatory muscle contraction through stimulation of periodontal proprioceptive，so as to reflectively adjust the occlusal contact intensity，direction，and the distribution of the contact point. With such a reflex regulation mechanism of occlusal contact on masticatory muscles，abnormal occlusal contact can alter the contraction of masticatory muscles which could be damage to the chewing apparatus. Therefore，avoiding unnecessary occlusal contact has become an important part of a treatment plan，such as that in prosthesis design. Here we put forward a new concept，the freedom of occlusion，which refers to the degree of the satisfaction of the occlusion contact in occlusion function. The greater the degree of occlusal freedom，the more comfortable the occlusal function is，and the less possible the occlusal contact to interrupt the occlusion function.

Key words: occlusion, temporomandibular joint, masticatory muscle, mandibular movement, chewing function

摘要：

上下牙咬合接触是完成咬合功能的必要条件。咬合接触由咀嚼肌收缩产生，同时其通过刺激牙周本体感受器，反射性调节咀嚼肌的收缩特征，进而调整咬合接触的强度、方向以及接触点的分布。由于存在咬合接触对咀嚼肌的这种反射性调节机制，一些异常咬合会引起咀嚼肌的异常收缩，从而损伤相应组织。因此，避免不必要的咬合接触是修复体设计等咬合治疗的重要内容。笔者在此提出咬合自由度的概念，用以描述咬合接触与不接触以及它们的动态变化对咬合生理功能的满足程度。咬合自由度越大，说明咬合运动越自如，咬合接触对咬合生理功能的满足度越高、干扰性越小。

关键词: 咬合, 颞下颌关节, 咀嚼肌, 下颌运动, 咀嚼功能