Shinya Kyoko, Shinya Akikazu, Nakahara Rizako, Nakasone Yuji, Shinya Akiyoshi
Department of Orthodontics, School of Life Dentistry at Tokyo, The Nippon Dental University. 1-9-20 Fujimi, Chiyodaku, Tokyo 102-8158, Japan.
Open Dent J. 2009 May 15;3:85-91. doi: 10.2174/1874210600903010085.
It is critical to clarify orthodontic load transfer mechanism from tooth to alveolar bone, and to determine the influence of applied orthodontic force on tooth behaviour. In this study, two dimensional (2-D) finite element (FE) models were constructed to simulate to mechanical behaviour observed during the initial movement of periodontal ligament (PDL) deformation, and to evaluate the effects of the presence of PDL and various restraint sites on tooth behaviour.A 2-D solid FE model of the tooth-PDL-alveolar bone system was constructed and investigated into stress distribution pattern and displacement. The first analysis was carried out with combinations of FE model with and without PDL. The second analysis was compared with three different sites restraint of alveolar bone. By incorporating PDL in FE models, excessively large stress values and deformation generated in a tooth and alveolar bone were relieved. Since restraint conditions did not affect a tooth and PDL, but had an effect on alveolar bone, orthodontic force necessary for tooth displacement was transmitted correctly. The results of this study revealed that inclusion of PDL in FE models is indispensable to transmit orthodontic force appropriately when investigating tooth behaviour for orthodontic treatment. Restrained sites affected stress distribution in alveolar bone.
阐明正畸力从牙齿到牙槽骨的传递机制，并确定正畸力对牙齿行为的影响至关重要。在本研究中，构建了二维（2-D）有限元（FE）模型，以模拟牙周膜（PDL）变形初始阶段观察到的力学行为，并评估PDL的存在和不同约束部位对牙齿行为的影响。构建了牙齿-PDL-牙槽骨系统的二维实体FE模型，并研究了应力分布模式和位移。第一次分析是在有和没有PDL的FE模型组合下进行的。第二次分析比较了牙槽骨的三种不同部位约束情况。通过在FE模型中纳入PDL，牙齿和牙槽骨中产生的过大应力值和变形得到了缓解。由于约束条件对牙齿和PDL没有影响，但对牙槽骨有影响，因此牙齿位移所需的正畸力得以正确传递。本研究结果表明，在研究正畸治疗的牙齿行为时，在FE模型中纳入PDL对于适当传递正畸力是不可或缺的。约束部位影响牙槽骨中的应力分布。
