拔除4个第一双尖牙正畸治疗满意病例Bolton指数的测量研究

Bolton analysis of four-first-premolar-extraction cases with good occlusion

目的 明确拔除 4个第一双尖牙对Bolton指数的影响以及对咬合关系的影响。方法 选取 4 3例拔除 4个第一双尖牙和 36例不拔牙治疗结果满意的病例 ,测量治疗后模型的牙齿宽度 ,计算比较其Bolton指数的差异 ;并计算不拔牙组在模拟拔除 4个第一双尖牙后的Bolton指数。结果 1 拔除 4个第一双尖牙治疗满意的病例其全牙比小于不拔牙组 ,其差别具有显著统计学意义 (P <0 .0 0 1)。 2 不拔牙治疗满意的病例在模拟拔除 4个第一双尖牙后的全牙比亦小于未拔牙之前 (P <0 .0 0 1) ,与实际测量的拔牙组的全牙比没有统计意义上的差别 (P =0 .94 )。结论 拔除 4个第一双尖牙病例治疗后的全牙比小于不拔牙病例。

Objective To investigate the effect of extraction of four first premolars on Bolton index and occlusion. Method The post treatment dental casts of 43 four first premolar extraction cases and 36 non extraction cases both with good occlusion were selected. Mesiodistal widths of mandibular and maxillary teeth were measured and Bolton index were calculated. Hypothetical extractions of four first premolars were performed on non extraction cases and then Bolton index were calculated again. Results 1. The overall ratios of real extraction cases and hypothetical extraction cases were lower than that of non extraction cases. The differences were found statistically significant. 2. There is no significant difference between hypothetical extraction cases and real extraction cases. Conclusion The change of Bolton index caused by extraction of four first premolars has no significant effect on occlusion.