As the use of intraoral scanners becomes routine in digital dentistry, digitally recorded palatal anatomy may become a potential adjunctive method for human identification when other primary identifiers are unavailable. This study evaluated palatal soft-tissue identification from intraoral scans under progressive postmortem deterioration and examined the influence of pre-freezing on identification reliability. Eighteen porcine maxillae were used as an ex vivo model and divided into fresh and pre-frozen groups. Intraoral scans were obtained over a 20-day observation period to simulate postmortem conditions. To address the instability of conventional whole-surface registration in deteriorated tissues, a reference point–based alignment strategy using palatal rugae landmarks was developed. Five surface-deviation features derived from aligned scans were used for identity-versus-stranger classification via discriminant analysis. The influence of postmortem time, comparison type, and specimen condition was further evaluated using generalized linear mixed-effects models. The proposed ruga-based alignment achieved an overall classification accuracy of 82.5%, with 89.3% sensitivity and 79.0% specificity, while independent validation yielded 84.2% accuracy. Although surface deviation increased significantly over time (p < 0.001), reflecting progressive tissue deterioration, postmortem time did not significantly affect ruga-based classification performance (p = 0.343). Importantly, pre-frozen did not significantly affect surface deviation (p = 0.542). These findings indicate that palatal rugae–guided alignment of intraoral scans showed good discriminatory performance under progressive postmortem deformation in this ex vivo porcine model. No statistically significant effect of pre-freezing was detected under the present experimental conditions. The results support the potential of ruga-based digital analysis as an investigational approach for postmortem identification workflows, while larger human validation studies are required before forensic implementation. Recording palatal soft tissues during routine intraoral scanning may provide an additional medico-legal benefit by enriching digital dental records. When antemortem scans are available, palatal morphology—particularly the rugae—could serve as a complementary feature for postmortem comparison, especially in delayed or compromised identification scenarios.
Mikó et al. (Fri,) studied this question.