Evaluation of postmortem histological changes in the human dental pulp in terms of postmortem interval detection

Aim: Postmortem interval (PMI) determination is one of the main study topics for forensic medicine. Postmortem interval determination generally give us the time interval in which deathay have occurred. Increasing the accuracy of PMI determination will only be possible with the newly developed methods. The aim of this study was to evaluate the histological changes in the human dental pulp in the postmortem process with experimental model and to demonstrate its usefulness in terms of PMI determination. Materials-Methods: In our study, we use 70 human 3rd molar tooths taken from the people who applied to oral and dental surgery deapartment. 70 tooths divided 7 groups each groups contain 10 tooths. The tooths in control group put into decalcifications liquid, other samples put into natural environment for putrefications. The other samples were taken on postmortem 7, 15, 30, 60, 90 and 180 days respectively. After decalcification, they were stained with Hematoxylin&Eosin and Masson Trichrom. Cell morphology, extracellular matrix, vascular structures, predentin layer, and collagen fibers were evaluated semiquantitatively under the microscop. Descriptive analyzes were carried out to give information about the general characteristics of the working groups. Regarding categorical variables, it is stated as n (%). Statistical analyses were performed by Friedman test. P value less than 0.05 was considered as significant. Results: All of the samples showed some histomorphologic changes correlated with PMI. Statistical analysis showed that significant difference between groups in terms of cell morphology, extracellular matrix, vascular structures, predentin layer, and collagen fibers. Conclusion: Dental pulp is valued tissue for PMI determination because of the its sheltered structure. Time-dependent postmortem progressive histologic changes in dental pulp can be used as an alternative method in the detection of PMI but this will be supported by further studies. Keywords: Postmortem interval, dental pulp, forensic dentistry