Evaluation of gingival tissue samples for predicting the time of death using histological and biochemical tests

Thanatochemistry also known as chemistry of death and is used to determine post mortem interval (PMI). It is arguably one of the critical steps in forensic investigation. Recent addition of analyzing biochemical changes along with the traditional methods have gained importance, as they help us to record very early changes in the tissue specimens. In this view, our study aimed to correlate both histological changes and enzymatic changes in gingival tissue samples at intervals of immediate, 1 h, 5 h, 24 h and 48 h after death. Histologic changes noted were loss of epithelial architecture, chromatin clumping, nuclear vacuolation, karryopyknosis, eosinophilia and wide intercellular junctions. Two enzymes which differentiate between the autolytic phase (acid phosphatase) and putrefactive phase (ammonia) of decomposition were evaluated using UV spectrometer. Results in our study demonstrated there were variations as in gradual increase in ammonia levels (1.13±0.24-26.6±2.09) and gradual decrease in acid phosphatase levels (5.61±0.67-1.25±0.53) at different time intervals till 48 h. The cellular changes in gingival tissue could also be related to time. The result of our study helps us to identify potential of enzymatic changes which when correlated with histological reports helps us to predict the time of death accurately. Replicating this experiment in various known taphonomic conditions and other enzymes could highlight the usefulness of gingival tissue samples in determining time of death.