DOI: 10.7860/JCDR/2018/36428.11991 Original Article Evaluation of Greater Sciatic Notch Parameters in Sex Determination of Hip Forensic Section Forensic Bone by Three-Dimensional CT Images SIAMAK SOLTANI1, MARYAM AMERI2, KAMRAN AGHAKHANI3, SOHEILA GHORBANI4 ABSTRACT Results: Among the GSN parameters, depth had no difference Introduction: Sex determination of an anonymous individual among males and females, in both right and left sides (p=0.767 is one of the main objective when human skeletal remains are and p=0.561, respectively); thus, was not useful in sex found, both in forensic investigation and archaeological studies. determination. GSN parameters including Depth (p=0.008), Post Aim: To evaluate the role of Greater Sciatic Notch (GSN) segment (p=0.017), and Index 2 (p=0.015) were different in right parameters in sex determination in the Iranian population by and left sides and cannot be considered for sex determination means of Three-Dimensional (3D) images reconstructed by without considering the sides. Moreover, Post angle (90.3%) and multi-slice Computed Tomography (CT). Post segment (89.5%) were found to have the most accuracy in sex determination. Materials and Methods: In the present cross-sectional study, 237 cases (121 females and 116 males) who received Pelvic Conclusion: Most of the parameters of GSN except for depth CT in radiology department of Rasoul-e-Akram Hospital were were useful for sex determination. Application of 3D-CT included. The GSN parameters including the width, depth micrographs in the present study helped us to easily quantify and posterior segment were applied to measure the 3D-CT sexual dimorphism in the GSN, suggesting 3D-CT can be radiographs of participant's hip bone using digital instruments considered as one of the valuable tools in practical forensic with an accuracy of 0.01º and 0.01 mm. SPSS version 21 was osteology investigation due to the great accuracy to measure used to analyse the data using the independent sample t-test, the sex differences. chi-square test, Pearson’s correlation test and Roc curve. Keywords: Childbearing, Human skeletal remains, Pelvic bones INTRODUCTION curved features, and it stored data format facilitates computerised Sex determination of an anonymous individual is one of the main geometrical analysis which helps to archive the data and use them step when human skeletal remains are found, both in forensic in the future [11,12]. There are many skeletal or collapse bodies investigation and archaeological studies. Hence, evaluation of in which determination of sex is the first step. No study has been sexual dimorphism of bones in the human population is interesting performed previously in Iran, using GSN 3D-CT scan for sex for both forensic experts as well as anthropologists [1]. determination. The hip bone is a perfect bone for sex determination; since, it The present study was done to evaluate the role of GSN reveals the dissimilarities between the two sexes and likewise parameters in sex determination in the Iranian population by displays a specific adaptation of women hip bone for childbearing means of 3D images, reconstructed by multi-slice CT. [2]. It is believed that for the sex determination of human skeleton the hip bone shows the highest accuracy levels [3]. The sexual MATERIALS AND METHODS dimorphism in the shape and size of the pelvis is very great since women giving birth to infants [4]. The parts of the pelvis which Study Design and Participants are more resilient to damage can be used for sex determination, In the present cross-sectional study, 237 cases (121 females and including the GSN and the auricular surface of the ilium [5]. In pelvis, 116 males) who had undergone pelvic CT for various reasons, in the GSN has an advantage because it is recognisable early in fetal Rasoul-e-Akram Hospital between September 2016 and February development. Studies have shown a statistically significant level of 2017 were included in the study. All the patients who met the sexual dimorphism in GSN [6]. The form and size of the GSN are inclusion criteria were enrolled in this six month study. Sample size associated with the size of the pelvic inlet. Therefore, multiple studies was calculated using α = 0.05, β = 0.2, µ1 = 27.06, µ2 = 25.41, SD1 have demonstrated that the GSN is highly accurate for estimating = 3.53, SD2 = 3.37 (20) and was estimated to be minimum sample sex when used alone [7-9]. of 140 cases. There are different methods for determination of sex in human skeletal remains including visual examination, bones anthropometric Inclusion and Exclusion Criteria measurements, anthropometric measurements with use of Patients who underwent pelvic CT according to their physician’s statistics, X-ray examination, and Microscopic examination [10]. CT advise were included in the study. Individuals who had severe is a high speed method and can capture high level details of bones’ pelvic injuries due to a fall or accident, those who had deformed or features and there is no need to remove soft tissue. Therefore, it is malformed bones and also with congenital abnormalities as well as a perfect instrument to save time to protect remains from physical non-Iranians, were excluded from the study. manipulation [11]. 3D-CT images of the pelvis reproduce complex Journal of Clinical and Diagnostic Research. 2018 Sep, Vol-12(9): HC01-HC05 1 Siamak Soltani et al., Sciatic Notch Parameters in Sex Determination of Hip Bone www.jcdr.net Ethical Considerations sample t-test was used and a p-value of <0.05 was considered to The study was performed according to the Ethical principles of be statistically significant. The qualitative variables were evaluated declarations of Helsinki. The study is approved by Ethical Committee using chi-square test. Correlation coefficient (r) was evaluated by of Iran University of Medical Sciences. (Ethical code: IR.IUMS.FMD. Pearson’s correlation test to analyse the significance of relation REC 1396.9411223010) All patients were aware of the study and a between quantitative variables. Roc curve was used to determine written informed consent was obtained from each participant. the sensitivity and specificity of the parameters. Data Collection RESULTS The GSN parameters including the width, depth and posterior A total of 237 cases (121 females and 116 males) with the mean segment were applied to measure the 3D-CT radiographs of age of 50.53 years (20- 89 years) participated in this study. participants' hip bone using digital instruments with an accuracy Equality of means was evaluated by the independent Student’s t-test of 0.01º and 0.01 mm [Table/Fig-1]. The measured data with sex and p-values were calculated. Statistically significant differences information were then recorded in a checklist. At first, the GSN between means related to sex were found for parameters including landmarks (Pyriformis tubercle, Ischial Spine and the deepest point Max width (p<0.001), mid-width (0.001), Total angle (<0.001), Post of the GSN) were determined by Ruler Syngo software in the division angle (<0.001), Post Segment (<0.001), index 1,2,3 and 4 (<0.001). then the following parameters were measured. While there was no difference between Max depth and means related • Maximum width (AB): Measured as the distance between the to sex in right (p=0.767) and left side (p=0.561) [Table/Fig-2]. pyriformis tubercle (B) and the point of the Ischial spine (A). The parameters Depth (0.008), Post segment (0.017), and Index 2 • Mid width (EF): GSN width at midpoint of OC line. (0.015) showed statistically significant differences in two sides of the • Maximum depth (OC): Considered as the perpendicular body; however, the other parameters showed no differences in right distance between the deepest points of the GSN (C) to the and left sides and can be used for sex determination [Table/Fig-3]. maximum width. Correlations between all parameters and age were analysed using • Posterior segment (OB): Measured as the distance between Pearson's correlation coefficient test. There was no statistical pyriformis tubercle (B) and the point of O (Vertical cross- difference between age and most variables of the GSN in men sectional width and the maximum depth of GSN) (p>0.05). All of the parameters except right AB (r= -0.195, p=0.036), mid-width right (r= -0.328, p<0.001) and left (r= -0.352, p<0.001), • Index I=Depth OC/Width AB×100 index 3 right (r= -0.201, p=0.031) and left (r= -0.246, p=0.008) and • Index II=Posterior segment OB/Width AB×100 index 4 right (r= -0.196, p=0.035) had no correlation with age. In • Index III (EF/AB) comparison with men, significant correlation was found between • Index IV (EF/CO) age and right mid-width (r= -0.268, p=0.003), left mid-width (r= -0.290, p<0.001), left OB (r= 0.198, p=0.029), left index 2 (r=0.221, • Total angle=ACB: Measured as an angular distance between p=0.015), index 3 right (r= -0.381, p<0.001) and left (r= -0.483, the point of pyriformis tubercle (B), the deepest point of the p<0.001) and 4 right (r= -0.320, p<0.001) and left (r= -0.285, GSN (C) and the point of Ischial spine (A). p=0.002) (p<0.001) in women [Table/Fig-4]. • Posterior angle=BCO: was determined as an angular distance Roc curve was used to determine the sensitivity and specificity of between the point of pyriformis tubercle (B), deepest point of the parameters. The most accuracy in sex determination was seen the GSN (C) and the point of O.