[Molecular biological studies on teeth inquests].

This paper deals with the following three areas: 1. Age estimation of tooth based on the racemization of component amino acids On the age estimation of a subject's tooth, the whole dentin prepared from the central vertical section showed a correlation coefficient of more than 0.99. The soluble peptide extracted from the dentin provided the highest correlation compared with the total content of amino acids or insoluble collagens, suggesting its usefulness as a component for estimating the age. The racemization rate was the highest for Asp, followed by Glu and Ala in order. As to the site from which a test dentin is sampled, the ratio of Asp from the lingual section was higher than its counterpart from the labial section. It is also noteworthy that the dentin from deciduous teeth was as useful as the permanent teeth for estimating the age of juvenile. 2. DNA typing analysis using tooth as specimen The pulp in a dried tooth is removed, from which DNA in extracted for DNA fingerprinting with the Y-specific probe. The sex determination was possible using a tooth that had been extracted up to 21 months before. Furthermore, a 30-cycle repetition of PCR enabled to accurately determine the sex from the DNA specimen that was considerably degraded as well as from freshly sampled DNA. 3. Inspection by dentists The dental and roentgenographic records provided by the families allowed rapid personal identification in major disasters, traffic accidents, fires etc.(ABSTRACT TRUNCATED AT 250 WORDS)