Teeth in forensics: A review.

With the ever-increasing crime rate in our society, the field of forensic sciences has become highly evolved. Forensic dentists play a pivotal role in various areas of crime scene investigations and thereby help solve innumerable mysteries. Teeth appear to be vital pieces of evidence in several such investigations. Teeth are preserved in the closed cavities of the mouth and are generally resistant to the threatening environmental conditions that may be associated with the death of an individual, making them very useful in postmortem analysis. Teeth thus obtained may be useful in age estimation of the deceased victim or in determining his blood group. Identification of individuals in mass disasters can also be performed based on the unique morphological characteristics of the human dentition and through dental DNA fingerprinting. Again teeth play an all important role in catching a culprit through the positive correlation of the bite marks left behind at the crime scene and the suspect's own teeth marks. Thus, teeth prove to be an important adjunct in forensics. Its scope is ever-increasing with time, and a great amount of research is being carried out to implement the same. A PubMed, MEDLINE, and Scopus search was conducted of the past 70 years using several search terms like "Forensic odontology," "history of forensic odontology," "dental DNA fingerprinting," "forensic age estimation," "age estimation from teeth" and "bitemarks." Other articles and textbook references which were considered to be important were also included in this study. The articles gathered were divided into the following groups: history of forensic odontology, teeth and DNA (dental DNA fingerprinting), teeth and blood grouping, teeth and age estimation, and teeth in bite marks.

Determination of ABO Blood Groups and Rh Typing from Dry Salivary Samples.

INTRODUCTION: A unique blood group is a characteristic every individual possesses. Blood group antigens like A, B, D, H, etc., are found to be present on the cell surfaces of red blood cells (RBCs). Besides blood, these are also secreted in various body secretions like semen, sweat, amniotic fluid, and saliva. Blood grouping has several applications in forensic sciences and is also a major part of routine medical investigations. Presence of these antigens in saliva is dependent on the secretor status of an individual. Saliva samples at the crime scene are very crucial, as they help in deoxyribonucleic acid typing, sex determination, bite mark analysis, and blood grouping. Dried salivary samples are often obtained in more number of cases as compared with the wet form, due to the variable time lapse between the occurrence of the crime and the start of the investigation. Blood grouping from these samples proves to be very efficient. Thus, the present study aims at evaluating the accuracy of ABO blood group determination and Rh typing from dried salivary samples. Also, the study would establish the use of saliva as a noninvasive technique in routine blood examinations, especially in children who have needle phobia. MATERIALS AND METHODS: Blood grouping and Rh typing were performed on the dry salivary samples obtained from the 47 subjects using the absorption-inhibition technique. This was then compared with the results obtained using extraction socket blood and evaluated. RESULTS: The present study showed a 100% positive correlation for ABO blood grouping, but a mere 14.81% positive correlation for Rh typing between the dried salivary samples and the extraction socket blood. CONCLUSION: Dried salivary samples can thus be put to immense use in several areas of forensic investigations. It could also help in developing alternate methods for routine blood investigations in children and adults.How to cite this article: Velani PR, Shah P, Lakade L. Determination of ABO Blood Groups and Rh Typing from Dry Salivary Samples. Int J Clin Pediatr Dent 2018;11(2):100-104.