无牙颌印模不同配准方法的对比研究

Comparison of Different Registration Methods for Impressions of Edentulous Jaw

目的:比较无牙颌印模两种配准方法配准结果的准确性,探讨适合无牙颌印模的配准方法。方法:全口或半口牙列缺失要求传统全口义齿修复的患者,以开口与闭口两种方式取模,获得上颌模型12组,下颌模型10组,模型扫描仪扫描,STL格式保存。逆向工程软件分别使用最佳拟合对齐与手工多点+全局配准两种方法对开口式与闭口式印模进行配准,三维偏差分析。SPSS17.0,配对t检验,显著性标准双侧α=0.05。结果:偏差名义值阈值区间面积最佳拟合对齐组(上颌48.58%,下颌44.16%)<手工+全局配准组(上颌70.55%,下颌66.27%),上颌P=0.000,下颌P=0.014,差异有统计学意义。上下颌RMS(root mean square)、平均正、负偏差最佳拟合对齐组>手工+全局配准组,差异上颌有统计学意义,下颌无统计学意义。结论:无牙颌印模的配准,手工多点联合全局配准方法优于最佳拟合对齐方式,在上颌表现更突出。

Objective:To compare the registration accuracy of two methods used in edentulous jaw impressions,and to explore the suitable registration method.Methods:The impressions were taken by two methods,which were open-mouth and close-mouth.Twelve maxillary and 10 mandibular impressions were obtained and scanned by laboratory scanner,then saved in the format of STL.Open-mouth and close-mouth impressions were superimposed in reverse engineering software with two methods,respectively,i.e.Best Fit Alignment and Manual n points+Global Registration.Then the 3D deviation was showed.Results:The deviation nominal value range area percentage of Best Fit Alignment group(maxilla 48.58%,mandible 44.16%)<Manual+Global Registration group(maxilla 70.55%,mandible 66.27%).There was significant difference among maxilla and mandible(P<0.05).RMS(root mean square),mean positive,and negative deviation of Best Fit Alignment group were higher than those of Manual+Global Registration group,in which the differences of maxilla were statistically significant.Conclusion:Manual multi-point+Global Registration is better than the Best Fit Alignment for the impressions of edentulous jaw,especially in the maxilla.