Development of mechanics of efficient tooth movement for reduction of orthodontic treatment period

前牙移动的控制对正畸治疗的成功至关重要。在滑动力学中，可以通过将不同长度的动力臂焊接到拱线上来自由调节水平回缩力。因此，可以简单地应用针对所需类型的牙齿移动的力系统。这项研究的目的是确定什么水平的缩力，即多长的动力臂允许前牙缩回到所需的位置。选择右上中切牙受试者为靶牙。利用两点三维位移式磁敏传感器测量了不同水平回缩力作用下的牙体在滑动力学作用下的初始移动。传感器实时检测并记录目标牙齿的初始位移。研究了牙齿在矢状面上的运动轨迹。提示靶牙的旋转中心位置应根据所受拉力高度的不同而不同。因此，前牙可以通过操纵旋转中心的位置，或者更确切地说，缩力的高度，即动力臂本身的长度，在预定的过程中被倾斜到牙冠舌尖或牙根舌尖。这将对正畸医生为患者制定有效的治疗计划提供极大的帮助。

Control of anterior teeth movement is essential to the success of an orthodontic treatment. In Sliding Mechanics, horizontal level of retraction force can be freely adjusted by soldering various lengths of power arms to an arch wire. Therefore, the force system for desired type of tooth movement can be simply applied. The purpose of this study was to determine what level of retraction force, namely, what length of power arm allow the anterior teeth to retract to a desired position. Human subject with upper right central incisor was chosen as target tooth. Initial tooth movement under sliding mechanics with various horizontal retraction forces were measured by Two-point Three-Dimensional Displacement Magnetic Sensor Device. The sensors detected and recorded initial displacement of target tooth in real time. The tooth's motion trajectories projected on the sagital plane was studied. It was suggested that the location of center of rotation of the target tooth varies according to the height level of retraction force application. Therefore, anterior tooth can be tipped crown-lingually or root-lingually in a pre-determined course by manipulating the location of center of rotation or rather the height level of retraction force application, i.e. the length of power arms itself. This would be of great help to orthodontists for establishing efficient treatment planning for patients.