A comparative assessment of bite marks in analyzing the overlay generation using styrofoam sheet and modeling wax with the dental casts as one of the adjuncts for archiving the forensic records: An in vivo study

Introduction: Bite mark evidence is unique to an individual and plays an important role in the legal system. There has always been the need to develop newer materials for bite mark analysis that will have excellent reproducibility as well as reliability. Aim: The present study aimed to evaluate the efficacy of styrofoam sheets and modeling wax with time-dependent changes when compared to the routine dental cast models. Materials and Methods: The present study included thirty volunteers and their bite marks were taken on the styrofoam and wax sheet materials that were traced on the transparent sheet and evaluation of the bite marks on the two materials were carried out at an interval of 1 day for 3 alternate days and grades were given, respectively. ANOVA test and t -test were used for statistical analysis. Results: The comparison between the styrofoam sheet and wax sheet with the dental cast on day 1 proved to be excellent materials for reproducibility, but from day 3 onward, the styrofoam sheet showed changes in bite registered area; whereas wax sheet maintained its registered dimensions. Conclusion: The study concludes that bite mark registration on styrofoam and wax sheet had excellent reproducibility on day 1, which makes these two materials advantageous in bite mark registration and overlay generation on the same day, whereas on day 3 and day 5, the styrofoam sheet showed changes with respect to bite registration and overlay generation, which questions the reliability of the styrofoam sheet for long-term record keeping when compared with the modeling wax.