Mandibular Ramus as an Indicator of Chronological Age Estimation and Gender Determination using Cone Beam Computed Tomography: A Retrospective Cross-sectional Study
TL;DR
CBCT-derived mandibular ramus measurements showed significant sexual dimorphism with 78% accuracy for gender determination, however, ramus height demonstrated a weak, non significant association with age, limiting its value for age estimation in the studied population.
Abstract
Introduction: Age and gender estimation from skeletal remains is vital in forensic identification. The mandible, being strong, durable and sexually dimorphic, provides reliable information. Cone Beam Computed Tomography (CBCT) enables accurate Three-Dimensional (3D) evaluation of mandibular structures. Existing two-dimensional (2D) imaging methods are affected by image distortion, while population-specific variations influence mandibular morphology; therefore, CBCT-based reference standards are warranted. The present study focuses on establishing population-specific reference values for forensic age and gender determination. Aim: To evaluate mandibular ramus dimensions using CBCT for forensic age estimation and gender determination. Materials and Methods: This retrospective cross-sectional study was conducted in the Department of Oral Medicine and Radiology at Karpaga Vinayaga Institute of Dental Sciences from March 2025 to June 2025. A total of 100 CBCT scans that clearly visualised the mandible and met the primary inclusion criteria of individuals aged 7-58 years were selected using consecutive retrospective sampling. CBCT images (CS 9600, Carestream Dental LLC) were reviewed using Digital Imaging and Communications in Medicine (DICOM) software, and five mandibular ramus parameters-coronoid height, condylar height, ramus height, maximum ramus breadth, and minimum ramus breadth-were measured in millimetres (mm). Age and gender were recorded as demographic variables. Statistical analysis was performed using IBM Statistical Package for Social Sciences (SPSS) version 27.0. Student’s t-test/Welch’s t-test and Analysis of Variance (ANOVA) were used for group comparisons; Pearson correlation and linear regression were used for age association, and discriminant function analysis (Wilks’ Lambda) was applied for gender prediction. A significance level of p≤0.05 was considered statistically significant. Results: Males showed higher mean coronoid height (61.51±4.42 mm) and condylar height (70.48±6.00 mm) compared to females (55.78±4.19 mm and 64.70±4.28 mm, respectively). Discriminant function analysis correctly classified 78% of individuals, with 34/40 females (85%) and 44/60 males (73.3%) correctly identified. Mandibular ramus height showed a weak and statistically non significant association with chronological age (R=0.206, p=0.121), indicating limited predictive value for age estimation in the studied population. Conclusion: CBCT-derived mandibular ramus measurements showed significant sexual dimorphism with 78% accuracy for gender determination. However, ramus height demonstrated a weak, non significant association with age, limiting its value for age estimation. Further large-scale studies are warranted.