Innovative design of closing loops producing an optimal force system applicable in the 0.022-in bracket slot system
Innovative design of closing loops producing an optimal force system applicable in the 0.022-in bracket slot system
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DOI：
10.1016/j.ajodo.2016.05.007
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发表时间：
2016-12-01
影响因子：
3
通讯作者：
Yoshida, Noriaki
中科院分区：
文献类型：
--
作者：
Sumi, Mayumi;Koga, Yoshiyuki;Yoshida, Noriaki
简介：大多数用于产生更高力矩比(M/F)的闭合回路需要复杂的钢丝弯曲，并且由于其复杂的结构，可能会引起卫生问题和不适。我们的目标是开发一种简单的环路设计，可以产生最佳的力和M/F比。方法：通过改变泪滴环的横截面缩小量的比例和长度以及环的位置，研究一种能产生高M/F比和理想受力水平的环的设计。采用切线刚度法进行结构分析，计算了作用在闭合环上的力和力矩。结果：通过激活一个10 mm高、横截面为0.019×0.025或0.021×0.025英寸、距离尖牙3 mm、距离尖牙1/4~1/3 mm的泪滴环，可产生9.3的M/F比(高到足以实现前牙的可控移动)和约250g的力水平。结论：我们开发的简单的环设计为前牙的后退提供了最佳的力和M/F比，并且适用于0.022英寸的槽系统。
Introduction: Most closing loops designed for producing higher moment-to-force (M/F) ratios require complex wire bending and are likely to cause hygiene problems and discomfort because of their complicated configurations. We aimed to develop a simple loop design that can produce optimal force and M/F ratio. Methods: A loop design that can generate a high M/F ratio and the ideal force level was investigated by varying the portion and length of the cross-sectional reduction of a teardrop loop and the loop position. The forces and moments acting on closing loops were calculated using structural analysis based on the tangent stiffness method. Results: An M/F ratio of 9.3 (high enough to achieve controlled movement of the anterior teeth) and an optimal force level of approximately 250 g of force can be generated by activation of a 10-mm-high teardrop loop whose cross-section of 0.019 x 0.025 or 0.021 x 0.025 in was reduced in thickness by 50% for a distance of 3 mm from the apex, located between a quarter and a third of the interbracket distance from the canine bracket. Conclusions: The simple loop design that we developed delivers an optimal force and an M/F ratio for the retraction of anterior teeth, and is applicable in a 0.022-in slot system.