错畸形患者的Pont指数的测量分析

Study of Pont's index of malocclusion patients with different dental Angle classifications

目的通过对错畸形患者的Pont指数的测量分析,探讨Pont指数与安氏各类错畸形的关系。方法选择南京医科大学附属口腔医院正畸科就诊的错畸形患者的初始记存模型382副,按照安氏Ⅰ、Ⅱ1、Ⅱ2、Ⅲ类分组,测量上颌切牙牙冠宽度、上颌牙弓中段宽度以及上颌牙弓后段宽度,并计算Pont指数。结果前磨牙指数、磨牙指数均没有性别间差异。不同类型的错畸形人群的前磨牙指数和磨牙指数有统计学差异。结论安氏各类错畸形存在着不同程度、不同表现的牙冠宽度-牙弓宽度比例不调,形成机制复杂,且各不相同。牙弓宽度的不足是错畸形的主要原因之一。

Objective To compare Pont＇s index among subjects with different malocclusions of the Angle＇s system in an orthodontic population and to investigate the relationship between Pont index and different malocclusion groups of the Angle＇s system. Methods The study employed the pre-treatment models of 382 patients （187 males, 195 females ,aged from 17 to 25 years） selected from the records of the Orthodontic Department, Stomatological Hospital of Jiangsu Province. The subjects were from four malocclusion groups, Class Ⅰ, Class Ⅱ division 1, Class Ⅱ division 2, and Class Ⅲ, with the corresponding Angle＇ s classification characteristics. The mesiodistal dimensions of the maxillary, incisors and arch width were measured using callipers （ accurate to 0. 02 mm） and the Pont＇s indexes were determined. The data were analysed with statistic methods and compared with each other. Results The results revealed that the index of premolar or molar was statistically different in different classified malocclusions. However,there were no significant differences between males and females. Conclusion The dissonance between the tooth size and arch width is one of the etiologies of malocclusion.