Integrating Advanced Radiological Imaging to Enhance Sex Estimation Beyond Classical Anthropological Methods: Population-Specific Models Based on Paranasal Sinuses Volume and Craniometric Data

Sex estimation is a cornerstone of biological profiling in forensic anthropology. However, in cases involving badly decomposed, burnt, or fragmented remains, traditional assessments may be unfeasible, requiring alternative approaches, such as radiological and medical imaging. The cranium is a valuable indicator of sex, yet its dimorphic traits may be fragmented or altered, hindering interpretation. In such scenarios, radiological techniques targeting protected cranial structures—such as the paranasal sinuses—offer a promising alternative. Although these sinuses exhibit sexual dimorphism, their full potential for sex estimation remains partially underexplored. This study aimed to develop a logistic regression model for sex estimation in a contemporary Italian population based on volumetric measurements of the frontal, maxillary, and sphenoid sinuses, combined with selected cranial linear dimensions (biorbital breadth, upper facial height, and nasal spine length). CT scans from 222 individuals were analyzed. Volumetric measurements were obtained from 3D sinus models individually segmented from the CT scans, while linear cranial dimensions were measured on volume-rendered 3D skull reconstructions. Two predictive models were developed on a training subset and subsequently validated on an independent validation subset, both achieving an overall accuracy of approximately 80% in both phases. The most predictive variables were the volumes of the right frontal and maxillary sinuses, upper facial height, and nasal spine length, which showed the most significant sexual dimorphism. These findings are consistent with the literature on sexual dimorphism of paranasal sinuses and reflect the anatomical variability of structures like the sphenoid sinus. This study demonstrates that volumetric assessment of paranasal sinuses combined with selected cranial dimensions can provide more reliable sex estimation in forensic contexts. The integration of radiological imaging with statistical modelling offers a practical framework for situations where conventional skeletal analysis is compromised, reinforcing the role of advanced radiology in expanding the methodological toolkit of forensic anthropology.