Assessment of Sexual Dimorphism from the Mastoid Triangle Using 3d CT scan in Nepalese Population

Authors

  • Pankaj Kumar Singh Kathmandu University School of Medical Sciences, Nepal https://orcid.org/0000-0002-6681-9532
  • Raj Kumar Karki Kathmandu University School of Medical Sciences, Nepal
  • Abdul Sami Khan Kathmandu University School of Medical Sciences, Nepal
  • Dhiraj Kumar Shah Kathmandu University School of Medical Sciences, Nepal
  • Sushant Bhardwaj Kathmandu University School of Medical Sciences, Nepal

DOI:

https://doi.org/10.3126/bjhs.v6i2.40330

Keywords:

Autopsy, Computed Tomography, Forensic Anthropology, Mastoid process, Mastoid Triangle, Raj Kumar Karki

Abstract

Introduction: Skull plays an important role, second only next to pelvis for sex determination. In skull, mastoid and occipital region due to its anatomical location is the most protected region, offering high resistance to decomposition and any form of tempering. With the intension of studying sexual dimorphism in the mastoid region involving mastoid process, we initiated this study. The technique we adopted was first introduced by Paiva and Segre, i.e. measuring the distance between three cranio-metric land mark (Porion, Mastoidale, and Asterion) and calculating the area of the triangle to study sexual dimorphism.

Objective: The objective of this study is to determine sex based on mastoid triangle dimensions measured in 3D reconstructed computed tomography of the skull.

Methodology: The study included 196, 3D reconstructed CT scan images of skull, 98 of which were males and 98 of which were females. The three craniometric points were marked to demarcate the mastoid triangle on both side (mention the software used).Heron’s formula was used for measurement of mastoid triangle areas.

Result: Descriptive statistics and the student t-test revealed that males have larger mastoid triangle dimensions in all measurements than females, with a significant difference (p<0.000) between them. The paired t-test revealed no statistically significant difference (p<0.05) between the right and left sides. Apart from angle asterion (p<0.05) on the right side, no other mastoid triangle angles on either side showed a significant difference. The predictability of mastoid triangle measurements and areas was determined using a discriminant function and ROC curve analysis. The calculated mastoid triangle measurements and areas were 72.5 % of Asterion to Porion, 74.5 % of Asterion to Mastoidale, 86.3 % of Mastoidale to Porion, and 88.2 % of areas, respectively.

Conclusion: The study findings suggest that mastoid triangle could be used to determine gender in the case of fragmentary skull remains by the forensic experts in the course of investigation. In order to generalize the data nationally, an autopsy-based, large sample size study on different age groups should be conducted.

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Author Biographies

Pankaj Kumar Singh, Kathmandu University School of Medical Sciences, Nepal

Assistant Professor, Department of Forensic Medicine

Raj Kumar Karki, Kathmandu University School of Medical Sciences, Nepal

Associate Professor, Department of Forensic Medicine

Abdul Sami Khan, Kathmandu University School of Medical Sciences, Nepal

Lecturer, Department of Forensic Medicine

Dhiraj Kumar Shah, Kathmandu University School of Medical Sciences, Nepal

2nd year Resident, Department of Forensic Medicine

Sushant Bhardwaj, Kathmandu University School of Medical Sciences, Nepal

Medical Officer, Department of Emergency

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Published

2021-11-03

How to Cite

Singh, P. K. ., Karki, R. K. ., Khan, A. S. ., Shah, D. K. ., & Bhardwaj, S. . (2021). Assessment of Sexual Dimorphism from the Mastoid Triangle Using 3d CT scan in Nepalese Population. Birat Journal of Health Sciences, 6(2), 1486–1491. https://doi.org/10.3126/bjhs.v6i2.40330

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Section

Original Research Articles