Sexual dimorphism in the angles between Frankfort horizontal plane and craniofacial profile landmarks.

OBJECTIVE: This study aimed to evaluate sex-related differences in angular parameters defined between the Frankfort horizontal plane (FHP) and craniofacial profile landmarks, and to investigate the applicability of these parameters for sex estimation. MATERIALS AND METHODS: A total of 218 individuals (109 females, 109 males) who underwent cranial computed tomography (CT) imaging were retrospectively included in the study. Using lateral craniofacial views, ten angular parameters were measured between the FHP and anatomically defined craniofacial axes. Sex-related differences were assessed using independent samples t-tests. Pearson correlation analysis was performed to evaluate relationships between measurements. Multivariate Adaptive Regression Splines (MARS) and Multiple Logistic Regression models were constructed to assess the discriminative performance of angular parameters in sex classification. RESULTS: All angular parameters except FHP-(sm-po) demonstrated statistically significant differences between female and male individuals (p ≤ 0.05). The MARS model achieved a classification accuracy of 94.95%, with a sensitivity of 93.58% and a specificity of 96.33%. The logistic regression model yielded a slightly lower overall accuracy of 93.1%. CONCLUSION: Craniofacial angular measurements referenced to the FHP reveal significant sex-related differences in craniofacial morphology. When combined with multivariate statistical models, these angular parameters provide high accuracy in sex estimation. The findings suggest that angular analysis of the craniofacial profile may represent a complementary approach for sex estimation, with potential relevance for forensic and anthropological applications.