The measurement of tooth displacement during final occlusal stage and physiological clucidation of the stomatognathic function -using the changed pathway of the jaw movement after orthodontic treatment-

点击翻译按钮获取中文摘要

The aim of this study was to measure the minute tooth movement during mastication, especially at the final stage of occlusion, and to understand the stomatognathic function in order to find the relation with occlusal condition. In this study, we have put great emphasis on the following items.1. The measurement of the minute displacement of toothWe have measured the actual minute displacement of the tooth using the available optical fiber displacement sensor (ST-3713 IWATSU). Because of no necessity for contacting the target, we could measured such displacement without disturbing the intrinsic displacement of the tooth.Additionally, a dynamic simulation of periodontal ligament was performed to investigate the transmission and absorption of the occlusal impact force applied to the tooth using a non-linear dynamic finite element method. The results revealed the mechanical background of periodontal ligament (The 4th Symposium on Oromaxillofacial Biomechanics).2. The elucidaton of the stomatognathic functionTo evaluate tooth displacement during functional occlusion, we investigated tooth displacement, masticatory movement and occlusal force. That is to say, by the media of efficiency of food destruction, we both theoretically investigated the pathway of masticatory movement during final occlusal stage (J.Jpn.Soc.Stomatognathic Funct., vol.3 No.2 1997) and clinically observed the data measured by recording apparatus (MM-JI-E,Shofu) (J.Jpn.Soc.Stomatognathic Funct., vol.3 No.2 1997).To exame the way that the stomatognathic function is controlled during the time course of changing of relative position of upper and lower teeth, we also measured such changing of occlusal force. We have recognized the significant relationship between the change of the balancing point of occlusal force and the stomatognathic function (J.Jpn.Orthod.Soc., in press).