Key Laboratory of the Ministry of Education for Optoelectronic Measurement Technology and Instrument, Beijing Information Science and Technology University, Beijing, China.
Department of Oral Anatomy and Physiology and TMD, School of Stomatology, Air Force Medical University, Xi'an, China.
Int J Oral Sci. 2021 Sep 8;13(1):29. doi: 10.1038/s41368-021-00133-5.
The use of traditional finite element method (FEM) in occlusal stress analysis is limited due to the complexity of musculature simulation. The present purpose was to develop a displacement boundary condition (DBC)-FEM, which evaded the muscle factor, to predict the dynamic occlusal stress. The geometry of the DBC-FEM was developed based on the scanned plastic casts obtained from a volunteer. The electrognathographic and video recorded jaw positional messages were adopted to analyze the dynamic occlusal stress. The volunteer exhibited asymmetrical lateral movements, so that the occlusal stress was further analyzed by using the parameters obtained from the right-side eccentric movement, which was 6.9 mm long, in the stress task of the left-side eccentric movement, which was 4.1 mm long. Further, virtual occlusion modification was performed by using the carving tool software aiming to improve the occlusal morphology at the loading sites. T-Scan Occlusal System was used as a control of the in vivo detection for the location and strength of the occlusal contacts. Data obtained from the calculation using the present developed DBC-FEM indicated that the stress distribution on the dental surface changed dynamically with the occlusal contacts. Consistent with the T-Scan recordings, the right-side molars always showed contacts and higher levels of stress. Replacing the left-side eccentric movement trace by the right-side one enhanced the simulated stress on the right-side molars while modification of the right-side molars reduced the simulated stress. The present DBC-FEM offers a creative approach for pragmatic occlusion stress prediction.
传统有限元法（FEM）在咬合应力分析中的应用受到肌肉模拟复杂性的限制。本研究旨在开发一种回避肌肉因素的位移边界条件（DBC）-FEM，以预测动态咬合应力。DBC-FEM 的几何形状是基于志愿者的扫描塑料模型开发的。采用肌电图和视频记录的颌位信息来分析动态咬合应力。志愿者表现出不对称的侧向运动，因此，在左侧偏心运动的应力任务中，进一步分析了右侧偏心运动 6.9mm 长的参数，以分析右侧的咬合应力。此外，还使用雕刻工具软件进行虚拟咬合修正，旨在改善加载部位的咬合形态。T-Scan 咬合系统被用作体内检测的对照，以确定咬合接触的位置和强度。使用本研究开发的 DBC-FEM 进行计算得出的数据表明，牙表面的应力分布随咬合接触而动态变化。与 T-Scan 记录一致，右侧磨牙始终显示接触和更高水平的应力。用右侧的偏心运动轨迹代替左侧的偏心运动轨迹会增加右侧磨牙的模拟应力，而右侧磨牙的修正会降低模拟应力。本研究开发的 DBC-FEM 为实用咬合应力预测提供了一种创新方法。
