Upadhyay Madhur, Shah Raja, Agarwal Sachin, Vishwanath Meenakshi, Chen Po-Jung, Asaki Takafumi, Peterson Donald
Division of Orthodontics, University of Connecticut Health;
Private Practice.
J Vis Exp. 2018 Jul 24(137):57339. doi: 10.3791/57339.
A proper understanding of the force system created by various orthodontic appliances can make treatment of patients efficient and predictable. Reducing the complicated multi-bracket appliances to a simple two-bracket system for the purpose of force system evaluation will be the first step in this direction. However, much of the orthodontic biomechanics in this regard is confined to 2D experimental studies, computer modeling/analysis or theoretical extrapolation of existing models. The objective of this protocol is to design, construct and validate an in vitro 3D model capable of measuring the forces and moments generated by an archwire with a V-bend placed between two brackets. Additional objectives are to compare the force system generated by different types of archwires among themselves and to previous models. For this purpose, a 2 x 4 appliance representing a molar and an incisor has been simulated. An orthodontic wire tester (OWT) is constructed consisting of two multi-axis force transducers or load cells (nanosensors) to which the orthodontic brackets are attached. The load cells are capable of measuring the force system in all the three planes of space. Two types of archwires, stainless-steel and beta-titanium of three different sizes (0.016 x 0.022 inch, 0.017 x 0.025 inch and 0.019 x 0.025 inch), are tested. Each wire receives a single vertical V-bend systematically placed at a specific position with a predefined angle. Similar V-bends are replicated on different archwires at 11 different locations between the molar and incisor attachments. This is the first time an attempt has been made in vitro to simulate an orthodontic appliance utilizing V-bends on different archwires.
正确理解各种正畸矫治器产生的力系统可以使患者的治疗高效且可预测。为了评估力系统，将复杂的多托槽矫治器简化为简单的双托槽系统将是朝着这个方向迈出的第一步。然而，这方面的许多正畸生物力学仅限于二维实验研究、计算机建模/分析或现有模型的理论推断。本方案的目的是设计、构建并验证一个体外三维模型，该模型能够测量置于两个托槽之间的带V形弯曲的弓丝所产生的力和力矩。其他目标是比较不同类型弓丝之间以及与先前模型所产生的力系统。为此，模拟了一个代表一颗磨牙和一颗切牙的2×4矫治器。构建了一个正畸钢丝测试仪（OWT），它由两个多轴力传感器或测力传感器（纳米传感器）组成，正畸托槽连接在这些传感器上。测力传感器能够测量空间所有三个平面内的力系统。测试了两种类型的弓丝，即三种不同尺寸（0.016×0.022英寸、0.017×0.025英寸和0.019×0.025英寸）的不锈钢弓丝和β钛弓丝。每根弓丝都有一个单一的垂直V形弯曲，该弯曲以预定角度系统地放置在特定位置。在磨牙和切牙附件之间的11个不同位置，在不同的弓丝上复制相似的V形弯曲。这是首次在体外尝试模拟在不同弓丝上使用V形弯曲的正畸矫治器。
