计算机辅助测量上颌第一乳磨牙牙冠与其不锈钢预成冠形态差异

Computer-aided measurement of the morphological difference between primary maxillary first molar crown and its preformed stainless steel crown

目的:比较中国华北地区儿童上颌第一乳磨牙临床牙冠与2种相应不锈钢预成冠(preformed stainless steel crown,SSC)形态差异。方法:制备中国华北地区116个完整上颌第一乳磨牙的重建样本3D模型,计算机辅助测量,分别与韩国SSC(A组)、美国SSC(B组)比较,分析其差异。结果:A、B组牙冠整体差异面积(mm 2)分别是13.31±2.44和22.57±5.97(P<0.05)。A组冠指数等9项测量项目均值存在统计学差异(P<0.05)。B组颊舌侧平均近远中径比均值等12项检测项目存在统计学差异(P<0.05)。结论:韩国和美国SSC均与我国儿童第一乳磨牙形态存在显著差异,韩国SSC整体差异面积较小,存在显著差异项较少。

Objective:To compare the morphological difference between primary maxillary first molar crown and the corresponding preformed stainless steel crown(SSC).Methods:3D models of 116 primaxy maxillary first molar crown were prepared and measured by computer.The morphologic measurements were compared with those of the preformed SSC of south Korea(group A)and SSC of USA(group B).The difference between the 2 groups was analyzed.Results:The overall area difference(mm 2)of group A and B were 13.31±2.44 and 22.57±5.97 respectively(P<0.05).There were statistical differences in the mean values of group A in 9 measurement items such as crown index(P<0.05).There were statistical differences in the mean values of group B in 12 measurement items such as the ratio of buccal and lingual average mesiodistal diameter(P<0.05).Conclusion:There is significant difference of the morphological characteristics of primary maxillary first molar between the 2 kinds of preformed SSCs and that of Chinese children.The overall area difference of south Korea SSC is less with fewer different measurement iterms than that of USA SSC.