Assessment of Anatomical Uniqueness of Maxillary Sinuses through 3D–3D Superimposition: An Additional Help to Personal Identification

SIMPLE SUMMARY: Personal identification is a paramount activity in forensic anthropology and can be achieved through the comparison of antemortem and postmortem images. Among the most individualizing skeletal structures are paranasal sinuses, which have been extensively investigated for identification purposes, with great emphasis on frontal sinuses. This paper extends this research line and assesses the uniqueness of the maxillary sinuses by applying 3D superimposition to investigate the reliability of these sinuses as reference anatomical structures for personal identification. Models of maxillary sinuses were acquired twice from CT scans to simulate antemortem and postmortem images; then, they were superimposed by pairing models from the same individual and from different individuals. The point-to-point distance between the models was used as a proxy to evaluate if the models belong to the same person. The optimal results suggest that maxillary sinus are reliable indicators of identity, although further research is needed to evaluate the performance of the method when the surface of the maxillary sinuses undergoes modifications due to pathological conditions. ABSTRACT: Paranasal sinuses represent one of the most individualizing structures of the human body and some of them have been already analyzed for possible applications to personal identification, such as the frontal and sphenoid sinuses. This study explores the application of 3D–3D superimposition to maxillary sinuses in personal identification. One hundred head CT-scans of adult subjects (equally divided among males and females) were extracted from a hospital database. Maxillary sinuses were segmented twice from each subject through ITK-SNAP software and the correspondent 3D models were automatically superimposed to obtain 100 matches (when they belonged to the same person) and 100 mismatches (when they were extracted from different individuals), both from the right and left side. Average RMS (root mean square) point-to-point distance was then calculated for all the superimpositions; differences according to sex, side, and group (matches and mismatches) were assessed through three-way ANOVA test (p < 0.017). On average, RMS values were lower in matches (0.26 ± 0.19 mm in males, 0.24 ± 0.18 mm in females) than in mismatches (2.44 ± 0.87 mm in males, 2.20 ± 0.73 mm in females) with a significant difference (p < 0.001). No significant differences were found according to sex or side (p > 0.017). The study verified the potential of maxillary sinuses as reliable anatomical structures for personal identification in the forensic context.