Morphometric Analysis of Mandibular Ramus Indices for Sex Prediction Using Digital Orthopantomograms (OPGs) and the GNU Image Manipulation Program (GIMP) Software

TL;DR

This study uses digital X-rays and free software to accurately predict sex based on jawbone measurements in a central Indian population.

Contribution

The study introduces a cost-effective, open-source method for sex prediction using mandibular ramus indices from digital OPGs.

Findings

Males had significantly larger mandibular ramus dimensions than females across all four measured parameters.

Condylar ramus height and maximum ramus breadth were the strongest predictors of sex.

The method showed high reliability and reproducibility for forensic sex estimation.

Abstract

Background: Sex determination forms a crucial part of human identification in forensic medicine, anthropology, and clinical practice. The mandible is a durable and morphologically dimorphic bone, making it valuable for sex estimation. This is crucial in the forensic investigation. Advances in digital radiography and open-source software, such as the GNU Image Manipulation Program (GIMP), allow precise morphometric analysis, potentially enhancing the accuracy of forensic investigations.

Aim: The study aimed to predict sex by calculating mandibular morphometric indices from digital orthopantomograms (OPGs) using the GIMP software in a central Indian population.

Materials and methods: This cross-sectional study analyzed 500 archival OPGs (250 males and 250 females aged 20-40 years) obtained from the Department of Dentistry, AIIMS Nagpur. Four mandibular parameters, including condylar ramus height, projective ramus height, maximum ramus breadth, and minimum ramus breadth, were measured bilaterally using the GIMP software under double-blind conditions.

Results: All four mandibular parameters showed statistically significant sexual dimorphism (p < 0.001), with males displaying larger linear dimensions than females. All four parameters showed significant dimorphism, with condylar ramus height and maximum ramus breadth contributing most strongly to sex prediction. The mean condylar ramus height was 58.89 mm in males and 52.36 mm in females; projective ramus height was 53.73 mm vs. 47.94 mm; maximum ramus breadth was 31.80 mm vs. 27.42 mm; and minimum ramus breadth was 25.55 mm vs. 23.12 mm. Regression analysis confirmed significant differences after adjusting for age. Discriminant function analysis demonstrated that condylar ramus height and maximum ramus breadth contributed most strongly to the sex classification.

Conclusion: Mandibular morphometric indices obtained from OPGs using the GIMP software are reliable indicators of sex, with significant sexual dimorphism in the ramus dimensions. This cost-effective and reproducible method has the potential to enhance forensic identification protocols, especially where DNA or conventional methods are unavailable.

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