Variations of dental diagenesis between submerged and buried samples over the first postmortem year in clandestine environments

Burial conditions have a strong influence on the postmortem changes in dental tissue. However, microscopic postmortem changes to dental tissues within a forensic time frame have rarely been investigated and/or reported. In this study, pig (Sus scrofa domesticus) heads were buried and submerged in two simulated clandestine environments, with timely investigations into changes to their teeth at three-month intervals over the course of a full calendar year. Major tissue modifications were observed in buried samples, with the loss of outer dentin fibers in the crown beginning earlier than three months. Significant processes also occurred in both samples, but at variable rates between environments. These included: regional dentin transparency throughout dental roots, damage to the inner dentin, growth of bacterial colonies at the dentin-enamel junction, and loss of pulp pigmentation and tissue. These findings evidence previously unknown patterns of taphonomic changes to teeth which will impact variable PMI and interment environment estimation studies. Future studies are necessary to examine if these results are replicable in human dentition and to map further taphonomic patterns over longer time periods.