安氏Ⅱ类错畸形牙冠宽度和Bolton指数测量分析

Study in the mesiodistal width of teeth and Bolton index of Angle's ClassⅡ malocclusion patient

目的分析安氏Ⅱ类错畸形患者的Bolton指数,并探讨其上下牙量关系对其症状及疗效的影响。方法以安氏Ⅱ类1分类和2分类错畸形患者各100例为研究对象,分别进行牙冠宽度测量并计算Bolton指数。结果安氏Ⅱ类1分类错的前牙宽度比安氏Ⅱ类2分类错大,差异有统计学意义。Bolton指数不调的基本分布情况为:指数正常组>指数过小组>指数过大组。Bolton指数前牙比和全牙比呈现安氏Ⅱ类2分类错>安氏Ⅱ类1分类错,但其差异无统计学意义。结论安氏Ⅱ类错中有约50%病例Bolton指数在正常值范围之外,存在上下牙量不协调。

Objective To investigate Bolton index of Angle＇s Class Ⅱ malocclusion patients and to study the influences of an upper and lower tooth size relations on the symptoms and curative effect. Methods 100 casts of Class Ⅱ division 1 and Class Ⅱ division 2 malocclusion were selected, respectively. Mesiodistal width of teeth was measured and Bolton Index was calculated. Results The results indicated that the sum of mesiodistal width of maxillary anterior teeth in Class Ⅱ division 1 malocclusion were larger than that in Class 11 division 2 malocclusion with significant differentce. The ratio of Bolton Index among the normal ranges was larger than that among lower ranges and among higher ranges. Bolton Index of Class Ⅱdivision 2 malocclusion was larger than that Class Ⅱ division 1 malocclusion without ignificant differentce. Conclusion More than half of all patients have the Bolton ratio outside the normal ranges and the maxillary and mandibular teeth size discrepancy.