Abstract
Sex determination is a key component of forensic identification, especially in cases involving fragmented or decomposed human remains where conventional skeletal markers are unavailable. The maxillary sinus and nasal structures are protected craniofacial components that exhibit sexual dimorphism and may aid sex estimation. This study evaluated computed tomography (CT)-based anthropometric measurements of these structures for sex determination in an Egyptian population using machine learning (ML). A comparative cross-sectional study was conducted on 195 adult Egyptians (100 females, 95 males) from Upper Egypt (Assiut, n = 104) and Lower Egypt (Benha, n = 91). CT scans of the paranasal sinuses were analyzed to obtain six maxillary sinus dimensions and three nasal measurements. Age and ten additional engineered features were derived, yielding 20 features for ML analysis. Two ML frameworks differing in the sequence of feature selection and hyperparameter optimization were evaluated using six classifiers and five feature-selection methods. Performance was assessed using accuracy, area under the receiver operating characteristic curve (AUC), precision, recall, F1-score, and specificity. Significant sex-related differences were observed in several measurements, with regional variation between Upper and Lower Egypt. Framework 2 generally outperformed Framework 1. The best-performing models achieved AUCs of 0.771 and 0.768, while the highest accuracy reached 74.4%. Nasofrontal angle, nasion-tip distance and mean anteroposterior maxillary dimension were the most consistent predictors. CT-based nasal and maxillary sinus anthropometry shows moderate utility for forensic sex estimation in Egyptians. ML improved classification by capturing complex morphometric relationships, with nasal measurements emerging as robust sex-discriminative markers.