三维几何形态学在下颌骨性别推断中的应用

A geometric morphometric study on sexual dimorphism in mandible

目的 使用基于标志点的三维几何形态法对下颌骨进行分析,评估下颌骨形状和大小的性别差异,为进一步了解下颌骨的形态特征及性别推断提供新思路和理论依据。方法 纳入164名北方汉族成年人(男性80名,女性84名)的颅面部薄层CT图像进行三维重建,获取了18个地标,采用普鲁克氏叠加、主成分分析和回归分析等评估了下颌骨大小和形状的性别差异。结果 异速生长分析显示下颌骨大小对形状的影响具有统计学意义(P <0.001),下颌骨大小和形状均具有性别差异,男性下颌骨大于女性,PCA图显示男性和女性下颌骨的重叠较多,逻辑回归表明总体性别推断准确率为67.1%~89.6%。结论 下颌骨大小比形状提供了更多的性别推断信息,当形状和大小信息结合分析时,性别分类精度会较大程度提高。

Objective To investigate the sexual dimorphism in the size and shape of the mandible using geometric morphometric techniques which are based on marker points,to provide a further exploration of morphological characteristics of the mandible,new ideas and theoretical foundation to support sex difference.Methods The craniofacial thin-layer CT images of 164 northern Han Chinese adults(80 males and 84 females)were used in the study,and threedimensional coordinates of 18 landmarks were acquired.Sex differences in mandibular size and shape were assessed using the generalized procrustes superimposition,principal component analysis,and regression analysis.Results Allometric analysis showed a statistically significant effect of mandible size on shape(P<0.001),the significance of the sex differences were found in size and shape,with male mandibles larger than female mandibles,PCA plots showed considerable overlap of the male and female mandible along the extracted PCs,and logistic regression showed that the overall sex inference accuracy was 67.1%to 89.6%.Conclusion Male and female mandibles differ more in size than in shape,and when shape and size information are combined in the analysis,the accuracy of sex classification is improved to a greater extent.