Bitemarks in forensic odontology: aspects, study methodology and critical analysis issues

OBJECTIVES The bitemarks found at crime scenes have been considered, for a long time, useful elements or crucial evidence for obtaining sentences. However, over the years various critical issues have arisen concerning the identification findings of the bite injuries, which have led to the issuing of verdicts of unjust condemnation of the defendants. The common orientation, is to abandon the exclusive use of bitemarks as judicial evidence. This study aims to highlight the characteristics, typologies and production mechanisms of bitemarks, describe and compare the different identification analytical methods and underline the current trends of the international scientific community. MATERIALS AND METHODS A systematic review of the scientific literature, consisting of textbooks and scientific articles, was carried out. Furthermore, the updated guidelines of the American Board of Forensic Odontology were examined, the report "Strengthening Forensic Science in the United States: A Path Forward", drawn up by the Committee on Identifying the Needs of the Forensic Science Community of the National Research Council and the recommendations of the Texas Forensic Science Commission. DISCUSSION The analysis of bitemarks usually occurs in cases of sexual violence, murder and abuse of minors. The characteristics of the lesions can be influenced by many elements. The most challenging analytical factor is the interpretation of human bitemarks left on the skin. There are several identification techniques, such as conventional and digital two-dimensional and three-dimensional methods. Over the years, scientific orientation has widely questioned the certainties of being able to identify a suitable suspect of a crime through the exclusive analysis of bite lesions. Factors such as the experience of the operators, the impossibility of establishing the uniqueness of the marks left on the integumentary tissues due to critical issues inherent in the distortion, as well as the difficulty of reliably duplicating the impressions, have led the American Board of Forensic Odontology to considerably revisit the guidelines relating to the study and use of bitemarks. Current scientific research, to date, advises against taking into consideration any judicial evidence relating only to bite injuries during criminal trials. CONCLUSIONS Over the years, the analysis of bite injuries using conventional and digital techniques has proved useful as a tool for identifying suspects and victims of committed crimes, in order to solve many criminal cases. However, the critical issues inherent in the veracity of the evidence produced in court have prompted the scientific community to reconsider the uniqueness of the marks inflicted by human dentition on the integumentary tissue and the identification of potential criminals exclusively through the analysis of bite lesions. Currently, forensic odontologists are adopting a more prudent and reflective attitude regarding the production of evidence based on the analysis of bitemarks during criminal trials. Further scientific research will be fundamental in order to allow evidence-based qualitative analyses, useful for achieving optimal results in terms of certainty of the evidence to be produced in court.