Sex estimation using subpubic angle from reconstructed three-dimensional computed tomography pelvic model in a contemporary Malaysian population

Abstract

Research in forensic anthropology is recent in Malaysia due to limited access to documented skeletal collections. However, advanced imaging techniques provide virtual bone samples for use in morphometric studies to establish populationspecific standards by virtual anthropology. This study examined sexual dimorphism in the subpubic angle using a threedimensional computed tomography model of the pelvis, in a contemporary Malaysian population. The sample comprised multidetector computed tomography (MDCT) scans of 50 male and 50 female adults. Segmentation of the MDCT scans was performed using 3D Slicer, and four landmarks were acquired using Stratovan Checkpoint for the subpubic angle measurement. The technical error of measurement (TEM), relative TEM, and coefficient of reliability (R) exhibited high reliability in measurements. Results showed that the subpubic angle in males was 68.6°±7.6° and in females 87.4°±6.5°. The subpubic angle in females was significantly larger than in males (P<0.001). Inverse correlation was found between the subpubic angle and age, in both males (r=-0.449, P<0.01) and females (r=-0.385, P<0.01). The overall accuracy of sex estimation using the subpubic angle was 94% (P<0.001). The subpubic angle, with a demarcating point of 78.6°, showed a sensitivity and specificity of 94% in the classification of female individuals. In conclusion, sex estimation using the subpu bic angle is highly accurate, with a high degree of expected sensitivity and specificity in the Malaysian population.

Measurement of Subpubic Angle in Radiograph

“…Though our study findings cannot be generalized for our population due to the smaller sample size, this widely accepted simple rule of 90° SPA for sex determination may not still be applicable in our population as mean SPA in the male in our study is way more than the cut-off value. 4,5,6,7,8,9 SPA in our study is comparable to the SPA in the study done by Akhlaghi et al (140.0° ± 14.3° in male and 101.0° ± 13.3° in female), but wider than the SPA in above mentioned other similar studies. 8 The differences may be due to the different ethnic groups studied.…”

“…The subpubic angle in the female is morphologically different from the subpubic angle in males with a widely accepted cut-off value of 90° for the discrimination. 4 However, our study showed a mean SPA in male (104.72° ± 10.47°) more than 90°. Though our study findings cannot be generalized for our population due to the smaller sample size, this widely accepted simple rule of 90° SPA for sex determination may not still be applicable in our population as mean SPA in the male in our study is way more than the cut-off value.…”

“…Mohd Ali et al found smaller SPA than the widely accepted cut-off value in females (87.4° ± 6.5°) as well. Demarcating point to discriminate between females and males in their study was 78.6° 4. …”

“…It is V-shaped in males and U-shaped in the female. 4 Although many studies evaluating subpubic angles are available worldwide, no such study is available in Nepal. Thus, this study was aimed to measure the subpubic angle and correlate it between male and female.…”

Mean Subpubic Angle of Patients Visiting Department of Radiodiagnosis of a Tertiary Care Hospital: A Descriptive Cross-sectional Study

“…Sex estimate using SPA is highly accurate. 3,4 The size of the birth canal is determined by the size of the SPA, which is a significant criterion in vaginal delivery. Determining the normal range of SPA in different populations would undoubtedly aid obstetrics in the prediction of obstructed labor and, hence, minimize maternal mortality by considering rational treatment plans.…”