The applications of three-dimensional computed tomography images of the greater sciatic notch for sex determination in forensic anthropology aspect in Thai population
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Abstract
Background: The identification of highly decomposed corpses or skeletons remains a significant challenge for forensic medical examiners. The pelvic bone, recognized for its reliability in sex determination, is frequently utilized through visual assessment as an initial step in such cases. However, the subjectivity of this method has prompted research into more accurate and objective approaches than traditional anatomical morphological evaluations.
Objective: The research was aimed to identify practical osteometric parameters of the greater sciatic notch, measured using a postmortem computed tomographic (PMCT) program, that have significant differences between male and female adults and provide high accuracy for sex determination in the Thai population. In addition, equation with high accuracy for sex determination using discriminant function analysis (DFA) was also developed.
Materials and methods: This study analyzed 385 Thai adults aged over 20, whose postmortem computed tomography (PMCT) scans included the hip region with an intact greater sciatic notch. The sample comprised 129 females and 256 males. The analyzed 6 osteometric parameters include two distances: PIIS-IS; the distance between the posterior inferior iliac spine (PIIS) and the ischial spine (IS), PIIS-SP; the distance between PIIS and Separating point (SP), a ratio of PIIS-SP to PIIS-IS (PIIS- SP/PIIS-IS), and three angles: Angle between planes passing PIIS and IS, and PIIS and DP (PIISA); Angle between planes passing PIIS and DP, and IS and DP (GSNA) and Posterior part when the GSNA is divided by DP-SP plane (GNSPA). Discriminant function analysis was used for data evaluation.
Results: Three-dimensional measurements of the greater sciatic notch demonstrated high reliability, with intra- and inter-observer ICC values exceeding 0.8 (p<0.05). All five measurements and the ratio achieved over 92% accuracy in multivariate analysis for cross-validated cases. DFA confirmed the suitability of all parameters for inclusion in the discriminant equation, which provided thresholds for sex determination: D<-1.03 indicated male, D>2.04 indicated female, and intermediate values were indeterminate, accounting for 67.73% of population variance.
Conclusion: This study demonstrates that all the selected measurements of the greater sciatic notch can effectively differentiate between male and female adults through the application of discriminant function with an overall accuracy of 92%.
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Personal views expressed by the contributors in their articles are not necessarily those of the Journal of Associated Medical Sciences, Faculty of Associated Medical Sciences, Chiang Mai University.
References
Criminal Procedure Code, Section 154. Act Promulgating the Criminal Procedure Code, BE 2477 (1934) [Internet]. Available from: https://www.icj.org/wp-content/uploads/ 2012/12/Thailand-Criminal-Procedure-Code-1934- 2008-eng.pdf
Thailand Missing Person Information Center. Statistics of Anonymous corpse in 2023 [Internet]. 2024 [cited 2024 Jan 25]. Available from: https://www.thaimissing. go.th/stat
Buzug TM. Computed tomography. In: Kramme R, Hoffmann K-P, Pozos RS, editors. Springer handbook of medical technology. Berlin, Heidelberg: Springer Berlin Heidelberg; 2011. p. 311-42.
Saukko PJ, Knight B. Knight’s forensic pathology. 4th Ed. London: Hodder Arnold; 2015.
Iscan MY, Steyn M. The human skeleton in forensic medicine. 3rd Ed. Springfield (IL): Charles C Thomas; 2013.
Gómez-Valdés JA, Quinto-Sánchez M, Menéndez Garmendia A, Veleminska J, Sánchez-Mejorada G, Bruzek J. Comparison of methods to determine sex by evaluating the greater sciatic notch: visual, angular, and geometric morphometrics. Forensic Sci Int. 2012; 221(1-3): 156.e1-7. doi: 10.1016/j.forsciint.2012. 04.027.
White TD, Folkens PA. The human bone manual. Amsterdam: Elsevier Academic Press; 2005.
Franklin D. Estimation of skeletal sex. Centre for Forensic Anthropology, The University of Western Australia, Australia: Elsevier Ltd; 2023.
Knecht S, de la Grandmaison GL, Bailet P, Rogez JM. Sex estimation from the greater sciatic notch: a comparison of classical statistical models and machine learning algorithms. Int J Legal Med. 2021; 135(6): 2603-13. doi: 10.1007/s00414-021-02700-1
Murial P, Bruzek J, Houet F, Cunha E. DSP: A tool for probabilistic sex diagnosis using worldwide variability in hip-bone measurements. BMSAP. 2005; 17(3-4): 3-4. doi: 10.4000/bmsap.1157
Blake KA. An investigation of sex determination from the subadult pelvis: A morphometric analysis [dissertation]. Pittsburgh (PA): University of Pittsburgh; 2011.
Walker PL. Greater sciatic notch morphology: Sex, age, and population differences. Am J Phys Anthropol. 2005; 127(4): 385-91. doi: 10.1002/ajpa.10422.
Boulay C, Tardieu C, Benaim C, Bénaim J, Chavet P, Marty C, et al. Three-dimensional study of pelvic asymmetry on anatomical specimens and its clinical perspectives. J Anat. 2006; 209(1): 57-66. doi: 10. 1111/j.1469-7580.2006.00513.x
Boonsonti S. Greater sciatic notch in sex determination by the metric method. J Thai Justice Syst. 2022.
Kim DH, Yoon HJ, Cho K, Oh JH. A comprehensive evaluation of the greater sciatic notch for sexual estimation through three-dimensional metric analysis using computed tomography models. J Leg Med. 2018; 35(1): 1-8. doi: 10.1016/j.legalmed.2018.09.006.
John F. Analysing the Validity of Random Number Generators [Internet]. 2023 [cited 2025 Mar 5]. Available from: https://kurser.math.su.se/pluginfile. php/20130/mod_folder/content/0/Kandidat/2023/ 2023_12_report.pdf?forcedownload=1
Koonkaew A. Choosing and using statistics and statistical analysis in research. Bangkok: Chulalongkorn University; 2023. p. 40-41.
Soltani S, Momenzadeh S, Afshar P, Hoseini M, Ghaffari H, Aliakbarian M, et al. Evaluation of greater sciatic notch parameters in sex determination of hip bone by three-dimensional CT images. J Clin Diagn Res. 2018; 12(9): 1-5. doi: 10.7860/JCDR/2018/ 36428.11991.
Bruzek J, Santos F, Dutailly B, Murail P, Cunha E. Validation and reliability of the sex estimation of the human os coxae using freely available DSP2 software for bioarchaeology and forensic anthropology. Am J Phys Anthropol. 2017; 164(2): 440-9. doi: 10. 1002/ajpa.23282.
