Dotzer Benedikt, Stocker Thomas, Wichelhaus Andrea, Janjic Rankovic Mila, Sabbagh Hisham
Department of Orthodontics and Dentofacial Orthopedics, University Hospital, LMU Munich, Goethestrasse 70, Munich 80336, Germany.
Department of Orthodontics and Dentofacial Orthopedics, University Hospital, LMU Munich, Goethestrasse 70, Munich 80336, Germany.
J Mech Behav Biomed Mater. 2023 Aug;144:105960. doi: 10.1016/j.jmbbm.2023.105960. Epub 2023 Jun 19.
Aim of this study was to determine the forces and moments during simulated initial orthodontic tooth movements using a novel biomechanical test setup.
The test setup consisted of an industrial precision robot with a force-torque sensor, a maxillary model and a control computer and software. Forces and moments acting on the corresponding experimental tooth during the motion simulations were dynamically measured for two 0.016" NiTi round archwires (Sentalloy Light/Sentalloy Medium). Intrusive (#1), rotational (#2) and angular (#3) tooth movements were simulated by a control program based on the principle of force control and executed by the robot. The results were statistically analysed using K-S-test and Mann-Whitney U test with a significance level of α = 5%.
Sentalloy Medium archwires generated higher forces and moments than the Sentalloy Light archwires in all simulations. In simulation #1 the mean initial forces/moments reached 1.442 N/6.781 Nmm for the Light archwires and 1.637 N/9.609 Nmm for the Medium archwires. In movement #2 Light archwires generated mean initial forces/moments of 0.302 N/-8.271 Nmm whereas Medium archwires generated 0.432 N/-9.653 Nmm. Simulation #3 showed mean initial forces/moments of -0.122 N/8.477 Nmm from the Light archwires compared to -0.300 N/11.486 Nmm for the Medium archwires.
The measured forces and moments were suitable for initial orthodontic tooth movement in simulations #2 and #3, however inadequate in simulation #1. Reduced archwire dimensions (<0.016″) should be selected for initial leveling of vertical malocclusions.
本研究的目的是使用一种新型生物力学测试装置来确定模拟初始正畸牙齿移动过程中的力和力矩。
测试装置由一个带有力 - 扭矩传感器的工业精密机器人、一个上颌模型以及一台控制计算机和软件组成。在运动模拟过程中，针对两根0.016英寸的镍钛圆丝（Sentalloy Light/Sentalloy Medium）动态测量作用在相应实验牙齿上的力和力矩。基于力控制原理的控制程序模拟侵入性（#1）、旋转（#2）和角向（#3）牙齿移动，并由机器人执行。使用K - S检验和Mann - Whitney U检验对结果进行统计学分析，显著性水平α = 5%。
在所有模拟中，Sentalloy Medium弓丝产生的力和力矩均高于Sentalloy Light弓丝。在模拟#1中，Light弓丝的平均初始力/力矩达到1.442 N/6.781 Nmm，而Medium弓丝为1.637 N/9.609 Nmm。在移动#2中，Light弓丝产生的平均初始力/力矩为0.302 N/-8.271 Nmm，而Medium弓丝为0.432 N/-9.653 Nmm。模拟#3显示，Light弓丝的平均初始力/力矩为-0.122 N/8.477 Nmm，相比之下，Medium弓丝为-0.300 N/11.486 Nmm。
在模拟#2和#3中，测量得到的力和力矩适用于初始正畸牙齿移动，但在模拟#1中不足。对于垂直错牙合的初始排平，应选择尺寸更小（<0.016英寸）的弓丝。
