Primary migration of a mini-implant under a functional orthodontic loading
Primary migration of a mini-implant under a functional orthodontic loading
复制标题
功能性正畸载荷下微型种植体的初次迁移
作者：
Joseph W. Pittman;Anand Navalgund;Steve H. Byun;Hechang Huang;A. Kim;Do
本研究的目的是检查是否皮质骨厚度和骨矿物质密度（BMD）可以解释一个微型种植体在功能性正畸切向负荷下的初期迁移在植入后的早期阶段。将微型种植体安装在人下颌骨切片中。在水合作用下，对微型种植体施加恒定的切向载荷（2 N）。蠕变是微型种植体周围骨中的时间依赖性粘弹性位移，评估为2 h载荷期间的位移变化。总迁移测量为结合初始弹性位移和蠕变的最大位移。取出微型种植体后，通过锥形束计算机断层扫描对所有标本进行扫描。测量植入部位周围骨体素的皮质骨厚度和BMD。骨密度与位移参数有显著相关性（p < 0.019），而皮质骨厚度与位移参数无显著相关性（p > 0.272）。在正畸功能负荷水平下，种植体附近的永久性骨变形是由于大量的蠕变发展造成的。BMD控制微型种植体系统在下颌骨中的初次迁移。粘弹性蠕变可在较小的恒定功能载荷水平下发展，导致微型植入物移位。目前的研究结果表明，在临床使用的小水平的功能性正畸载荷下，微型种植体可以发生移位。如果微型种植体周围活跃的骨重建加速了迁移，则导致微型种植体附近重要器官损伤的风险增加。
The objective of this study was to examine whether cortical bone thickness and bone mineral density (BMD) can explain the primary migration of a mini-implant under a functional orthodontic tangential loading at the early stage following implantation. Mini-implants were installed in human mandibular sections. A constant tangential load (2 N) was applied to the mini-implant under hydration. Creep, which is a time-dependent viscoelastic displacement in the bone surrounding the mini-implant, was assessed as the change in displacement during 2 h of loading. The total migration was measured as a maximum displacement that combined an initial elastic displacement and creep. After removal of the mini-implant, all specimens were scanned together by cone beam computed tomography. Cortical bone thickness and BMD were measured for the bone voxels surrounding the implant site. BMD had significant correlations with the displacement parameters (p < 0.019), but the cortical bone thickness did not (p > 0.272). Permanent bone deformation adjacent to the implant was observed to be resulting from substantial creep development under the orthodontic functional loading level. BMD controls the primary migration of the mini-implant system in mandibular bone. Viscoelastic creep can develop at a small constant functional loading level, leading to migration of the mini-implant. The current results indicated that mini-implant migration can develop under the small level of functional orthodontic load used in clinic. If the active bone remodeling around the mini-implant accelerates the migration, the risk of causing damage in vital organs next to the mini-implant increases.
影响因子：
2.4
作者：
Yamamoto, Ei;Crawford, R. Paul;Keaveny, Tony M.
通讯作者：
Keaveny, Tony M.
影响因子：
2.4
作者：
Bonivtch, Amber Rath;Bonewald, Lynda F.;Nicolella, Daniel P.
通讯作者：
Nicolella, Daniel P.