两种滑动法关闭拔牙间隙的比较研究

目的：探讨直丝弓矫治器治疗安氏Ⅱ类1分类错牙合]畸形过程中，采用主动结扎关闭间隙时，两种施力方式关闭拔牙间隙对牙齿移动的影响。方法：采用前瞻性配对设计，对30例拔除4个第一双尖牙的安氏Ⅱ类1分类病例进行配对，共配成15对，分为A、B两组，两组均采用主动结扎法关闭间隙，A组施力于弓丝上（弓丝法），B组施力于牙上（牙列法），对两组患者进行上颌牙齿移动的测量研究。结果：两种方法关闭间隙时，在所耗时间、前牙后移比率和消耗支抗方面无显著性差异（P〉0．05），在垂直方向上，弓丝法压低前牙0．5mm，牙列法压低前牙0．25mm，差异有显著性（P〈0．05）。结论：主动结扎关闭拔牙间隙时，采用施力于牙列上或施力于弓丝上的方式都可以，两种方法都能有效的关闭间隙。

Comparison of two ways closing extraction space

Objective To compare the difference of two space-closure ways using straight wire technique. Methods Thirty first premolar extraction cases were chosen and divided into two groups（A and B） for prospective paired t-test. In two groups, extraction spaces were closed by Active Pull Method （APM）of the sliding technique. In group A, the site of force was fixed on wire but in group Bontooth. Treatment materials, steps and appliance design in both groups were same. Measurements of dental model and cephalogram were taken. Results During closing sapce, the time, the ratio of anterior teeth movement and the desire for anchorage was not significantly different （P〉0.05）. The number of lowering anterior teeth was significant different,0.5mm in group A,0.25mm in group B （P〈0.05）. Conclusion Two methods were effective in closing space, but the site of force fixing on tooth was convenienter in group B.