Orthodontic Simulator for Three Dimensional Orthodontic Force Measurement

为了实现正畸模拟器，我们建立了一个仪器化的牙齿模型。这个模型是用于前牙的，构建在一个结合的前角和x阶段上。将前角台的旋转中心调整为牙齿的阻力中心，并将x台的平移方向调整为前后方向。因此，该模型可以模拟牙齿在正畸治疗下的运动。三维力的测量是由四个应变片的黄铜圆筒制成的负荷传感器。它可以测量前后力和矢状力矩。虽然应变幅值不大，但输出线性度良好，标定试验保证了测量系统的准确性。在这些组件之上，安置了人造树脂牙齿，使我们能够对模拟器做出逼真的形状。使用四个内固定的前牙模型和另外两个后牙模型构建牙弓。然后将矫治器固定在模拟器上，测量矫治力。该装置是0.018”或0.016”方形横截面的不锈钢丝。用结扎线将金属丝绑在粘附在树脂牙齿上的毯子上。通过加载到导丝上的重量模拟撤回力。实验结果表明，所建立的正畸力模拟器可用于正畸力的分析。

To realize the orthodontic simulators, we built a instrumented tooth model. This model is for anterior teeth, constructed on a combined gonio and x stages. The rotational center of the gonio stage is adjust to the center of resistance of the teeth, and the translation direction of the x stage is adjusted as the anteroposterior direction. Thus the model can simulate the movement of the teeth under orthodontical treatment. The three dimensional force was measured by the load cell made by the brass cylinder with four strain gages. It can measure the anteroposterior force and saggital moment. Although the strain magnitude was not so large, the output linearity was excellent and the calibration testing guarantee the accuracy of the measuring system. Above these components, there settled the artificial resin teeth which enable us to make the realistic form to the simulator. The tooth arch was constructed using the four instrumented anterior teeth models and two other posterior tooth model. Then the orthodontic apparatus was settled on the simulator and the orthodontic force was measured. The apparatus were stainless steel wires of .018" or .016" square cross section. The wire were tied with ligature wire to the blankets adhered to the resin tooth. The retraction force was simulated by the weight loaded to the wires. The measured results were satisfactory and it was proved that the simulator constructed is useful to analyze the orthodontic force generated by the orthodontic apparatus.