An In Vivo 3D Micro-CT Evaluation of Tooth Movement After the Application of Different Force Magnitudes in Rat Molar
An In Vivo 3D Micro-CT Evaluation of Tooth Movement After the Application of Different Force Magnitudes in Rat Molar
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DOI：
10.2319/071308-366.1
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发表时间：
2009-07-01
影响因子：
3.4
通讯作者：
Yoshida, Noriaki
中科院分区：
文献类型：
--
作者：
Gonzales, Carmen;Hotokezaka, Hitoshi;Yoshida, Noriaki
目的：目的：研究连续力作用下大鼠牙周膜间隙宽度和牙齿三维移动的纵向变化规律。材料与方法：采用镍钛弹簧，对左侧上颌第一磨牙施加10、25、50、100 g的近中力，连续作用28 d。在第0、1、2、3、10、14和28天对同一大鼠进行Micro-CT检查。从0到3天，在压力侧和张力侧测量PDL的宽度。在第0、10、14和28天，使用角度和线性测量来评估磨牙位置。有限元模型（FEM）构建，以评估初始应力分布，磨牙位移，和旋转中心的molar.Results：牙周膜宽度的初步评估显示，不同的力的大小之间没有统计学差异。施力后1小时记录牙齿移动，并随时间逐渐增加。从第10天开始，当施加10 g的力时，观察到更大的牙齿移动。结论：大鼠磨牙的运动主要包括近中倾斜、远中根外伸、近中根内压、腭倾斜和近中旋转。虽然在施加不同大小的力之后直到第3天的初始牙齿移动没有显著不同，但是在第28天，与较重的力相比，10 g的力产生更多的牙齿移动。（角度正交2009;79：703-714）。
Objective: To investigate the precise longitudinal change in the periodontal ligament (PDL) space width and three-dimensional tooth movement with continuous-force magnitudes in living rats.Materials and Methods: Using nickel-titanium closed-coil springs for 28 days, 10-, 25-, 50-, and 100-g mesial force was applied to the maxillary left first molars. Micro-CT was taken in the same rat at 0, 1, 2, 3, 10, 14, and 28 days. The width of the PDL was measured in the pressure and tension sides from 0 to 3 days. Angular and linear measurements were used to evaluate molar position at day 0, 10, 14, and 28. The finite element model (FEM) was constructed to evaluate the initial stress distribution, molar displacement, and center of rotation of the molar.Results: The initial evaluation of PDL width showed no statistical differences among different force magnitudes. Tooth movement was registered 1 hour after force application and gradually increased with time. From day 10, greater tooth movement was observed when 10 g of force was applied. The FEM showed that the center of rotation in the molar is located in the center of five roots at the apical third of the molar roots.Conclusion: The rat's molar movement mainly consists of mesial tipping, extrusion of distal roots, intrusion of mesial root, palatal inclination, and mesial rotation. Although the initial tooth movement after the application of different force magnitudes until day 3 was not remarkably different, 10 g of force produced more tooth movement compared with heavier forces at day 28. (Angle Orthod. 2009;79:703-714.)