It is generally believed that the pelvis is possibly
It is generally believed that the pelvis is possibly the most accurate bone in the human body for gender determination, with the accuracy being 95% when completed. In addition, it is estimated that the accuracy of gender identification from the subpubic angle, ventral arc, and composite is approximately 98%.
Gender determination of skeletons, particularly those of the victims of war or explosions that cause skeletal fragmentation, is not an easy procedure to undertake and complete successfully. Matching certain characteristics identified on dead bodies with data recorded during the life of an individual is very important in forensic medicine, and can be performed by fingerprint analysis, radiological methods, deoxyribonucleic PRX-08066 matching, anthropological methods, and other means that can facilitate sex identification. Radiography can contribute to gender determination by providing precise dimensions for which special formulas can be applied.
It is widely accepted that skeletal characteristics vary among different populations; therefore each population should have specific standards to improve the accuracy of identification. In this study, factors related to the pelvic bone including subpubic angles, pubic angles, X angles, length of the pubis, length of the ischium, ischiopubic index, pubis body width, ratio of the length of the symphysis pubis to the width of the pubis body, and ratio of the length of the symphysis pubis to the minimum width of the pubic superior ramus have not been assessed in prior studies and in Iran (except for the subpubic angle and ischiopubic index, which were evaluated in previous studies).
Methods Our study consisted of 100 male and 100 female patients who were referred by the physician to the radiology ward of the Rasoul Akram Hospital for anteroposterior pelvic radiography during 2013–2014. Exclusion criteria included non-Iranian patients, individuals under 18 years of age, patient dissatisfaction with study participation, patients with congenital or acquired skeletal abnormalities, individuals with hip fracture and underlying bone diseases, low-quality radiographic image, and pregnancy and childbirth during the last 3 months. After taking a standard radiographic image of patients in the supine position and an anteroposterior view of the pelvis (the distance of ray source was 100 cm from the patient and the tube was without any angle), these images were stored digitally, and the sex and age of patients were recorded on them. The variables were measured by ISK PACS CC workstation software. To increase numerical accuracy, measurements were carried out twice and the average was recorded. Both the measured variables and the methods of measurement are shown in Table 1 and Fig. 1.
Results The age range of the population extended from 18 years to 90 years, with an average age of 48.77 years. Two hundred individuals were evaluated; of them, 50% were men and 50% were women. The mean age of the men was 45.03 years and that of the women was 52.20 years. The measured variables were compared using the independent t test. The results showed that the subpubic angle, pubic ramus angle (Pubic Angles 1 and 2), and X angle were significantly different in men and women, as shown in Table 2. The ROC curve was used to determine the discriminatory power of these angles (Fig. 2). For the subpubic angle, the area under the curve was 94% for sex differentiation (Fig. 2A). In the study population, applying a differentiation point of 115.92°, sensitivity of 91%, specificity of 92%, and accuracy of 91.5%, the subpubic angle was different in men and women. In the studied population, significant differences were noted in the average size of the subpubic angle between men and women, with the average size in women being significantly more than that in men (p<0.000). For Pubic Angles 1 and 2 and for sex differentiation, the area under the curve was 94% and 86.4%, respectively (Figs. 2B and 2C). For Pubic Angle 1, the differentiation point was 79.42°, sensitivity 92%, specificity 84%, and accuracy 88%; therefore, there was a difference in the subpubic angle between men and women. For Pubic Angle 2, the differentiation point, sensitivity, specificity, and accuracy were, respectively, 67.98, 76%, 85%, and 80.5%. Significant differences were seen between in average size of Pubic Angles 1 and 2 between men and women, with the average size in men being significantly more than that in women (p<0.000). The area under the curve was 87% for X angle (Fig. 2D), and the differentiation point, sensitivity, specificity, and accuracy, were 85.95, 83%, 82%, and 82.5%, respectively, which show differentiation between men and women. There was a significant difference between X angle size in men, and the length of the pubis, length of the ischium, and ischiopubic index were significantly different in men and women as well (Table 3).