安氏Ⅱ~1类错与正常牙弓宽度的研究

Compared study of dental arch width between Angle class Ⅱ division 1 and normal occlusion

目的:以正常为对照,研究安氏Ⅱ1类错牙弓宽度的特点。方法:选择12～16岁的安氏Ⅱ1类错和正常各60例,取标准研究模型,利用3DSS(光栅扫描仪)扫描后,以Geomajic软件进行图像拟合处理,并测量上下颌牙弓前、中、后段长度,分析安氏Ⅱ1类错与正常牙弓宽度的差异。结果:①.正常男性上下颌牙弓宽度均比女性大,其中上颌牙弓及下颌后段牙弓宽度有显著性差异(P<0.05)。②.安氏II1类错男性上下颌牙弓宽度均大于女性,其中上颌牙弓后段及下颌牙弓前段、后段宽度有显著性差异(P<0.05)。③.安氏II1类错无论男女,上颌牙弓后段宽度明显小于正常,有显著性差异(P>0.05)。结论:安氏II1类错患者上颌牙弓小于正常牙弓,治疗时应扩展上颌后段牙弓使腭侧倾斜的后牙颊倾,或用牙弓与基骨联合扩展的方法加大上颌后段牙弓宽度,利于下牙弓前移,建立正常的磨牙关系。

Objective： Compard with normal occlusion, to analyze the characteristic of arch width of patients who fall into Angle class Ⅱ, division 1 malocclusion.Method： 60 patients with Angle class Ⅱ division Ⅰ malocclusion and 60 persons with normal occlusion were selected, both of which were 12-16 years old,study models were made. After the study models being scanned by 3DSS,they were treated by image fitting with Geomajic software. The width of anterior, middle,posterior segment of the upper and lower dental arch was measured, thus the difference of arch width between Angle class Ⅱ divisionl and normal occlusion was analyzed. Result： ①.Boys with normal occlusion had statistically significant wider dental arch width values on the upper posterior dentition and the lower anterior dentition than girls＇ counterparts. ②.In addition, boys with Ⅱ 1 malocclusion also had statistically significant wider lower posterior dental arch width than girls＇ counterparts. ③. The palatal upper posterior dental width values on the normal occlusion were statistically significantly larger than those on the Ⅱ 1 malocclusion for both sexes. Conclusion： The dental arch in class Ⅱ division 1 malocclusion should be expanded to accommodate the forward moving mandibular dental arch.