Nocturnal grinding is not the cause of joint disease, but one of its clinical manifestations. It is an attempt to instinctively eliminate bite interference spontaneously to save the joint response. However, it is not the case, the eyebrows and whiskers together, the more grinding the more chaotic set, the joint more disorderly. Therefore, many colleagues only see the second half of the relationship, mistakenly believe that night grinding teeth in the first, joint disease in the second. In fact, the teeth in the occlusal movement of the obstacle point, triggered the control of joint movement of multiple groups of muscles subconsciously twitch, the joint out of the appropriate position, and then spontaneous teeth filing, trying to eliminate these interference points, the formation of the phenomenon of night grinding teeth. In this way, it seems that the occlusal disorder of the teeth is the original sin as well.