Ceballos F, Deana N F, Alves N
Master Program in Dentistry, Faculty of Dentistry, Universidad de La Frontera, Temuco, Chile.
Student of Doctoral Program in Sciences in Applied Cellular and Molecular Biology, Universidad de La Frontera, Temuco, Chile.
BMC Oral Health. 2025 Jan 23;25(1):122. doi: 10.1186/s12903-025-05471-y.
Sex estimation is the first stage in the identification of an individual in the forensic context, and can be carried out from bone structures like the mandible. The aim of this study was to estimate sex from metric analysis of the mandible in cone beam computed tomography images (CBCT) of adult Chilean individuals.
Six mandibular measurements were analysed, five linear and one angular, in CBCT of adult Chilean individuals of both sexes. ROC Curve analysis was performed, with cut-off points, and of the overall model quality. Univariate discriminant function analysis was used to determine the accuracy of each measurement for sex estimation. Multivariate discriminant function analysis, both directly and by steps, was used to obtain the predictive value of the mandible including all the measurements.
The data included were 155 CBCT, 105 of females and 50 of males. The mandible presented great sexual dimorphism, with the mandibular ramus presenting greater predictive power than the mandibular body. When each mandibular measurement was analysed separately, the maximum height of the mandibular ramus presented the greatest predictive power (76.5%), while the mandibular angle was the least accurate parameter for sex estimation (58.1%). Direct method analysis presented 87.1% accuracy for sex identification of adult Chilean individuals, and joint analysis of maximum mandibular ramus height (MRH), corono-condylar distance and bigonial breadth presented 86.5% accuracy. In ROC Curve analysis the MRH was the variable with the greatest discriminating capacity (AUC = 0.833), MA was the only variable which presented no discriminating capacity (AUC = 0.386) and also presented low quality in model quality analysis.
Metric analysis of the mandible in CBCT images presents an acceptable accuracy for sex estimation in Chilean individuals, and its use for that purpose in forensic practice is recommended.
在法医鉴定中，性别估计是个体识别的第一阶段，可通过下颌骨等骨骼结构进行。本研究的目的是通过对智利成年个体锥形束计算机断层扫描图像（CBCT）中的下颌骨进行测量分析来估计性别。
对智利成年男女个体的CBCT图像中的六项下颌骨测量指标进行分析，其中五项为线性指标，一项为角度指标。进行ROC曲线分析，确定截断点和整体模型质量。采用单变量判别函数分析确定每项测量指标对性别估计的准确性。直接和逐步进行多变量判别函数分析，以获得包含所有测量指标的下颌骨的预测价值。
纳入的数据包括155例CBCT图像，其中女性105例，男性50例。下颌骨呈现出明显的性别二态性，下颌支比下颌体具有更强的预测能力。单独分析每项下颌骨测量指标时，下颌支的最大高度具有最强的预测能力（76.5%），而下颌角是性别估计中最不准确的参数（58.1%）。直接法分析对智利成年个体性别鉴定的准确率为87.1%，下颌支最大高度（MRH）、冠状突-髁突距离和下颌角宽度联合分析的准确率为86.5%。在ROC曲线分析中，MRH是具有最大鉴别能力的变量（AUC = 0.833），下颌角（MA）是唯一没有鉴别能力的变量（AUC = 0.386），并且在模型质量分析中质量较低。
CBCT图像中下颌骨的测量分析对智利个体的性别估计具有可接受的准确性，建议在法医实践中用于该目的。
