Application to forensic odontology of aspartic acid racemization in unerupted and supernumerary teeth

Racemization of aspartic acid in dentin protein during the human lifetime progresses with age. The extent of racemization of aspartic acid in coronal dentin of normal permanent teeth can be used in forensic odontology to estimate the age of an individual at the time of death (Ogino et al., 1985). A series of experiments was conducted with dentin separated from unerupted and supernumerary teeth of various ages in an attempt to evaluate the advantages and limitations of this age-estimation method. The current study on nine tooth specimens showed that some unerupted permanent teeth with normal-sized and -shaped crowns (impacted third molar, canine, and incisor) could be used to estimate the age of individuals at the time of death within +/- 4 years. However, supernumerary teeth (mesiodens, paramolar) with extremely tiny (length of crown: 4 approximately 5 mn) and abnormally shaped crowns could not be used for analysis. In such cases, the estimated age of individuals analyzed by the racemization method deviated considerably from their actual age.