A comparative evaluation of light microscopic features of normal oral mucosa and its time dependent autolytic changes in deceased individuals - An observational study.

Context: The postmortem interval refers to the amount of time elapsed between death and discovery of the body and estimation of which is challenging with the traditional methods. Aims: This study aims to investigate the potential of histologic autolytic features of buccal mucosa for the assessment of postmortem interval. Settings and Design: The study was conducted between February 2023 and November 2024 in the Department of Oral and Maxillofacial Pathology, Guru Nanak Institute of Dental Sciences and Research, in collaboration with the Department of Forensic Medicine and Toxicology, College of Medicine and Sagore Dutta Hospital, Kolkata, West Bengal. Materials and Methods: A total of 75 postmortem and 10 ante-mortem tissue samples were compared using hematoxylin and eosin and van Gieson's stains. The postmortem samples were categorized according to three PMI stages as early (<10 hours since death), intermediate (10-20 hours since death), and late (>20 hours since death up to the bloat stage). Statistical Analysis Used: Kruskal-Wallis test was performed to statistically analyze the obtained data. Results: The epithelial connective tissue separation was found to be significantly different among the three postmortem interval groups, whereas significant changes in the connective tissue, such as myofibril degradation, fatty tissue degeneration, and neural tissue degeneration were also noted. Moreover, decreased staining intensity of connective tissue through van Gieson's stain was also found to be statistically significant with the progression of postmortem interval. Conclusion: These findings indicate that microscopic evaluation of the buccal mucosa may be helpful for postmortem interval prediction.