Dentistry actually does have a big role in Crime Scene Investigation commonly known as CSI. It's really all about Forensic Dentistry which is the branch of dentistry that deals with the legal aspects of professional dental practices and treatment, with particular emphasis on the use of dental records to identify victims of crimes and their attackers, or accident victims. Their dental records morbidly speaking have identified many crime victims, even when nothing much else remains. Every individual's dental “mouth-prints,” like fingerprints are unique including bite-marks, fillings, missing teeth and more. Dentists keep very accurate records like radiographs (x-rays) and sometimes molds or models of their patients' mouths, which can be very helpful in a forensic situation. And not just in modern times, scientific analysis of fossil teeth has played a large role in paleontology, the study of prehistoric life, including the discovery and evolution of long gone species including prehistoric man right down to the details of their diets. All of this is evidenced by the markings and wear left on their teeth. Whether your friend was kidding or not dentistry has been a great friend to CSI. And by the way, be careful who you bite!