上颌快速扩展最佳时机的初步研究

目的:通过患者年龄、牙龄、骨龄,对上颌快速扩展扩弓效应的相关性分析,期望发现应用上颌快速扩展的最佳时机。方法:选择需上颌横向扩展的患者30例,年龄11～14岁,平均12.30岁,进行上颌快速扩展。摄左手腕掌指骨片,扩展矫治前后的上颌前部咬合片、头颅正位定位片。利用SPSS11.0软件包对数据进行t检验、多元线性回归、多元逐步回归分析。结果:年龄相近,扩展效应不一;骨龄与扩展效应具有一定的相关性,偏回归系数为-6.440,P值为0.045;牙龄与扩展效应具有高度相关性,偏回归系数为-1.289,P值为0.000。随着上颌第二恒磨牙的萌出、生长和建牙合,扩展效应明显下降。结论:在上颌第二恒磨牙萌出前进行上颌快速扩展,可在较短的治疗时间内获得所需的骨骼效应。

The preliminary study of the treatment timing for rapid maxillary expansion

PURPOSE: The aim of this study was to find the treatment timing of rapid maxillary expansion by investigating the relationship among the chronologic age, dental age, skeletal age and treatment effect of rapid maxillary expansion. METHODS: A sample of thirty patients who required rapid maxillary expansion was selected. The patients ranged in age from 11 to 14 years, with the mean age being 12.30 years . Assessment of the skeletal age was made with a hand radiograph before treatment. The posteroanterior cephalograms, occlusal radiograph of the maxilla were taken at the time of pretreatment and post-treatment. Paired t test and multiple regression analysis were used for statistical analysis. RESULTS: The results showed that the effects of rapid maxillary expansion were different even though the chronologic ages were similar. A negative correlation was found between the skeletal age and the expansive effect. Regressive coefficient was -6.440, P value was 0.045. There was a significant negative correlation between the dental age and the expansive effect. The regressive coefficient was -1.289, P value was 0.000. The expansive effect was on the decrease while the second maxillary molars erupted continuously. CONCLUSION: It is proposed that rapid maxillary expansion could be used successfully before the second maxillary molars erupt. The optimal orthopedic effect could be attained.