前磨牙拔除模式对Bolton指数的影响

The effect of premolar extractions on Bolton index

目的:观察模拟拔牙后Bolton指数的变化趋势。方法:按Bolton正常值和一个标准差,将213副符合研究标准的模型分为Bolton过小、正常、过大3组,比较各组拔牙前和模拟4种模式拔牙后全牙比和人数的变化,了解其变化趋势。结果:按4种拔牙模式拔牙后,各组的全牙比均比拔牙前减小,且有显著性差异;正常组和过大组的人数分别向过小组和正常组变化。结论:Bolton过小、正常、过大3组病例在模拟拔牙后,Bolton指数均出现减小趋势。

PURPOSE: The purpose of this study is to investigate the effect of premolar extractions on Bolton index. METHODS: 213 plaster casts were divided into Bolton big, normal and small groups according to Bolton normal value and one standard deviation. Bolton overall ratios and number of patients in each group were measured and compared between parameters before and after hypothetical premolar extractions. RESULTS: The Bolton overall ratios in each group were smaller after premolar extractions than those before extractions. Part of patients in the Bolton normal group and big group were changed into Bolton small group and normal group after premolar extractions, respectively. CONCLUSION: The Bolton overall ratios decreased after premolar extractions.