Find out how DNA is utilised in odontology for identification and bitemark analysis.
DNA in human identification – there are two review articles on the subject that you can read here, and here. They cover the basics of DNA from teeth – consider enamel to be an armoured coating for DNA. Its the hardest structure in the human body – which serves to protect the DNA within the pulp and the dentine from most postmortem assaults – but how do you get the DNA out? There are two main ways of doing this. The first is simple to section the tooth and then “scrape” out the pulpal material. Not an elegant solution to the problem and nor does it either maximise the amount of DNA available or minimise the potential risk of contamination. DNA contamination is a major issue, especially with the sensitivity of the new PCR techniques.
Instead, most authorities recommend that cryogenic grinding is used instead. Cryogenic grinding is the process of freezing and then grinding the tooth to a fine powder. This powder can then be used to extract DNA – it provides the maximum yield and reduces the chance of DNA contamination.