Written by Denice Higgins
Teeth are frequently used as a source of nuclear DNA for identification of unknown human remains1 especially when only skeletal remains are present. Teeth are the most resilient of the body’s tissues to postmortem degradation and have been shown to be a preferable source of DNA to bone.2 Of the many studies on nuclear DNA in teeth the majority have examined the tooth as a whole2, or just the pulp tissue3 and have utilized healthy unrestored teeth4 whilst disregarding the fact that pulp tissue breaks down in a relatively short period of time.5 Previous studies also give no consideration to the effects of age and disease processes. When modern human remains are located it is quite possible that not all the teeth will be available to choose from for analysis and that the teeth available will have been involved in disease processes and/or have been restored.
Principal sources of nuclear DNA in teeth are the odontoblasts and nucleated cells of the pulp tissues and cementocytes within the cellular cementum.6 Other potential sources of nuclear DNA are odontoblastic cells trapped within reparative dentine or retracted into the dentinal tubules, white blood cells within vessels present in accessory foramina passing through the root dentine or floor of the pulp chamber and periodontal cells captured in the cementum. A significant person to person variation in the DNA yield from various tooth regions has been noted previously but reasons for this were not explored.1 This study aims to target the dental hard tissues for presence of nuclear DNA and to explore the variation between and within individuals and the effects of age and disease on the DNA in these tissues.