Can Mental Index be used on CBCT images to determine sexual dimorphism?

ABSTRACT Objective: Radiomorphometric indices (RI) vary according to gender and age. The objective of this study was to assess bone quality in men and women, using tomographic images Methods: A total of 78 Cone Beam Computed Tomography (CBCT) images of female and male patients were analyzed. The images were obtained from LAPI-FOUSP database, São Paulo, Brazil, and the Mental Index, which is a quantitative index, was evaluated on those images. The images were divided into 2 groups: Group M – Men and Group W – Women and evaluated by one examiner in two different times (T1 and T2). The data was submitted to a statistical analysis with a 95% level of significance (p <0.05) Results: The ICC tests showed an average to good intra-examiner agreement. The age averages were: 48.46 ± 15.3 for group W and 53.87 ± 13.09 for group M. On the MI evaluation, statistically significant differences were observed between the two groups Conclusion: We concluded that MI can be used to determine sexual dimorphism, once the thickness of the mandible cortex in women is smaller than the thickness found in men.

摘要
研究目的：放射形态计量学指标（radiomorphometric indices, RI）的数值会随性别与年龄发生变化。本研究旨在借助断层影像评估不同性别受试者的骨质量。
研究方法：本研究共分析了78份男女患者的锥形束计算机断层扫描（Cone Beam Computed Tomography, CBCT）影像。这些影像取自巴西圣保罗的LAPI-FOUSP数据库，研究人员对其中的颏指数（Mental Index, MI）这一量化指标进行了评估。所有影像被分为两组：M组（男性组）与W组（女性组），并由同一名检查者在两个不同时间节点（T1与T2）分别完成评估。研究采用显著性水平为95%（p<0.05）的统计学方法对数据进行分析。
研究结果：组内相关系数（Intraclass Correlation Coefficient, ICC）检验结果显示，检查者自身的评估一致性处于中等至良好水平。两组受试者的平均年龄分别为：女性组（48.46±15.3）岁，男性组（53.87±13.09）岁。在颏指数评估中，两组间的差异具有统计学意义。
研究结论：本研究最终得出结论：由于女性下颌骨皮质厚度小于男性，因此颏指数可用于判定性别二态性。