Application of bone remodeling theories in the simulation of orthodontic tooth movements.
Application of bone remodeling theories in the simulation of orthodontic tooth movements.
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DOI：
10.1007/s000560050012
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发表时间：
2000-01-01
期刊：
影响因子：
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通讯作者：
Jager, A
中科院分区：
文献类型：
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作者：
Bourauel, C;Vollmer, D;Jager, A
为了模拟正畸牙的移动，建立了一个基于骨重塑理论的计算牙根周围骨对位和吸收的数值模型。该模型被用来计算不同类型的正畸牙齿移动，然后与基于临床经验的预期移动进行比较。为了模拟尖牙的运动，将尖牙根部理想化地建模为椭圆抛物面的形式，并用有限元程序进行处理。有限元模型加载了定义的力系统。两个模型假设被用来计算骨重建过程。首先在牙周韧带中施加机械载荷，然后在牙槽骨中施加机械载荷来模拟牙齿的移动：1.围绕阻力中心的近中倾斜(托槽处的力系统：孤立扭矩My=5 NMM)，2.围绕牙齿长轴的旋转(MZ=5 NMM)，3.围绕根尖的不受控制的倾斜(Fx=1 N，Mz=5 NMM)，4.尖牙后退(Fx=1 N，My=-9.5 NMM，Mz=5 NMM)，5.和6.挤出/侵入(Fz=+/-0.5 N，Fz=+/-0.5 N，MX=+/-2.5 NMM)。在假设阻力中心位置固定的前提下，计算正畸牙齿的移动，并与临床经验进行比较。结果表明，正畸骨改建的数值模型可以用于正畸牙移动的计算。然而，结果强烈地依赖于模型的假设。该模型模拟了基于牙周韧带负荷的骨改建，其结果与阻力中心位置的生物力学假设非常一致。然而，第二种模型出现了明显的副作用，特别是在模拟不受控制的倾倒、平移和入侵/挤出时。临床上，这些副作用是观察不到的。
A numerical model that calculates bone apposition and resorption around a tooth root on the basis of bone remodeling theories was developed to simulate orthodontic tooth movements. The model was used to calculate different kinds of orthodontic tooth movements, that were then compared with the expected movements based on clinical experience. For simulation of the movements the root of a canine was modeled in an idealized way in the form of an elliptical paraboloid and was processed with a finite element program. The finite element model was loaded with defined force systems. Two model assumptions were used to calculate the bone remodeling process. The mechanical loads firstly in the periodontal ligament and secondly in the alveolar bone were taken to simulate the following tooth movements: 1. mesial tipping around the center of resistance (force system at the bracket: isolated torque MY = 5 Nmm), 2. rotation around the long axis of the tooth (MZ = 5 Nmm), 3. uncontrolled tipping around the root tip (FX = 1 N, MZ = 5 Nmm), 4. canine retraction (FX = 1 N, MY = -9.5 Nmm, MZ = 5 Nmm), 5. and 6. extrusion/intrusion (FZ = +/- 0.5 N, MX = +/- 2.5 Nmm). Comparison with clinical experience was performed by calculating the orthodontic tooth movements based on the assumption of a fixed position of the center of resistance. It could be demonstrated that the numerical model of orthodontic bone remodeling can be used to calculate orthodontic tooth movements. However, the results are strongly dependent on the model assumptions. The model simulating the bone remodeling on the basis of the loading of the periodontal ligament delivers results that are in very good accordance with the biomechanical assumptions of the position of the center of resistance. However, marked side effects occurred with the second model, especially in the simulations of uncontrolled tipping, translation and intrusion/extrusion. Clinically, these side effects cannot be observed.