乳前牙反的追踪观察研究

A Follow-up Study of Anterior Deciduous Cross-bite

Wang Zuhua, She Bingyue, Qin Juncheng, et al
Department of Dentistry, the Second People\'s Hospital of Shuangliu County
Shi Zongdao
College of Stomatology, West China University of Medical Sciences

Abstract

　　Objective:　To determine the relationship between anterior deciduous crossbite and anterior permanent crossbite, Angle classification of malocclusion and class Ⅲ jaw relationship through a follow-up study in community children. Methods: A follow-up study was done six years later in 102 children who were out of 120 children having anterior deciduous crossbite detected in a survey of six years before. Other 102 children with normal occlusion of deciduous and permanent teeth were treated as the control group. Results: There were 51 out of 102 cases developed anterior permanent crossbite. In comparison with the group with 1～2 anterior deciduous crossbite, the group with more than two neighboring anterior deciduous crossbite had more significant probability to turn into anterior permanent crossbite, OR=6.8 (95%CI: 2.7～17.6). The patients with more than 2 neighboring anterior deciduous teeth crossbite had significantly more chance of developing Angle Ⅲ malocclusion and class Ⅲ jaw relationship than those in the control group and those with 1～2 anterior deciduous teeth crossbite. Conclusion: Clinical orthodontists should pay more attention to the patients with more than 2 neighboring anterior deciduous crossbite.

　　Key words:　anterior crossbite　Angle malocclusion classification　jaw relationship　jaw development

　　对乳牙期的前牙反,一些学者^［1～6］认为应早期矫治,否则会影响颌骨发育。据国内流行病学调查资料^［7］推测,我国有数百万2～6岁儿童患乳前牙反,故有必要对乳前牙反的转归进行调查分析。为此,作者对口腔社区调查中^［8］诊断为乳前牙反的儿童,于6年后进行追踪复查,其中102例得到随访。现将调查结果报道如下。

1　材料和方法

1.1　研究对象
　　1990年调查幼儿、中小学儿童2194人中诊断为乳前牙反者119例,其中102例6年后得到复查,男53例,女49例,复查时年龄9～14岁,平均11.7±1.5岁。为了比较乳前牙反对颌骨发育的影响,同时还将1990年调查中无乳前牙反,6年后复查,恒前牙亦无反的102名儿童作为对照组,其中男53名,女49名,复查时年龄10～14岁,平均11.8±1.1岁,进行磨牙关系及颌骨发育情况的检查。
1.2　检查方法
　　由5名口腔医师按同一标准检查恒前牙反情况,第一恒磨牙咬合关系及颌骨发育情况,记录检查结果。
1.3　检查标准
1.3.1　恒前牙关系　①正常覆:符合个别正常标准的前牙覆关系。②切:上下颌前牙切缘相对。③反:下前牙位于上前牙唇面前方,呈反覆盖关系。
1.3.2　第一磨牙关系　按Angle错分类标准^［3］,分为Ⅰ、Ⅱ、Ⅲ类错。
1.3.3　颌骨关系　按Simon分类^［3］,以眶平面为基准,肉眼观察判定颌骨位置。
1.3.4　乳前牙反分类　①Ⅰ类:1～2个乳前牙反;②Ⅱ类:乳前牙反的牙数大于或等于3,反牙不相邻;③Ⅲ类:乳前牙反的牙数大于或等于3,反牙相邻。

2　结　　果

2.1　乳前牙反与恒前牙反的关系
　　102例乳前牙反与6年后复查时恒前牙反的关系详见表1。表1可见,个别乳前牙反(Ⅰ类)演变为恒前牙正常覆和切的机率明显高于其他两组。与个别乳前牙反组相比,多个不相邻乳前牙反组演变为恒前牙反的危险度比值比为1.6(95%可信限0.4～7.5),未达到统计学显著水平;而多个相邻乳前牙反组演变为恒前牙反的危险度比值比为6.8(95%可信限2.7～17.6),达到统计学显著水平。