Coimbra Maria Elisa Rodrigues, Penedo Norman Duque, de Gouvêa Jayme Pereira, Elias Carlos Nelson, de Souza Araújo Mônica Tirre, Coelho Paulo Guilherme
Department of Orthodontics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Am J Orthod Dentofacial Orthop. 2008 Feb;133(2):188.e9-13. doi: 10.1016/j.ajodo.2007.07.017.
Understanding how teeth move in response to mechanical loads is an important aspect of orthodontic treatment. Treatment planning should include consideration of the appliances that will meet the desired loading of the teeth to result in optimized treatment outcomes. The purpose of this study was to evaluate the use of computer simulation to predict the force and the torsion obtained after the activation of tear drop loops of 3 heights.
Seventy-five retraction loops were divided into 3 groups according to height (6, 7, and 8 mm). The loops were subjected to tensile load through displacements of 0.5, 1.0, 1.5, and 2.0 mm, and the resulting forces and torques were recorded. The loops were designed in AutoCAD software(2005; Autodesk Systems, Alpharetta, GA), and finite element analysis was performed with Ansys software(version 7.0; Swanson Analysis System, Canonsburg, PA). Statistical analysis of the mechanical experiment results was obtained by ANOVA and the Tukey post-hoc test (P < .01). The correlation test and the paired t test (P < .05) were used to compare the computer simulation with the mechanical experiment.
The computer simulation accurately predicted the experimentally determined mechanical behavior of tear drop loops of different heights and should be considered an alternative for designing orthodontic appliances before treatment.
了解牙齿如何响应机械负荷而移动是正畸治疗的一个重要方面。治疗计划应包括考虑能满足牙齿所需负荷以实现最佳治疗效果的矫治器。本研究的目的是评估使用计算机模拟来预测激活三种高度的泪滴形曲后所获得的力和扭转。
75个内收曲根据高度分为3组（6、7和8毫米）。通过0.5、1.0、1.5和2.0毫米的位移对曲施加拉伸负荷，并记录产生的力和扭矩。曲在AutoCAD软件（2005；Autodesk Systems，阿尔法利塔，佐治亚州）中设计，并使用Ansys软件（版本7.0；Swanson Analysis System，卡农斯堡，宾夕法尼亚州）进行有限元分析。机械实验结果的统计分析通过方差分析和Tukey事后检验获得（P <.01）。使用相关性检验和配对t检验（P <.05）将计算机模拟与机械实验进行比较。
计算机模拟准确预测了不同高度泪滴形曲的实验确定的力学行为，应被视为治疗前设计正畸矫治器的一种替代方法。
