PubMed · 522860
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H E Amstutz. 1979. Practice problems.. https://pubmed.ncbi.nlm.nih.gov/522860/
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The amount of secondary dentin in a tooth has been used as one of several parameters in methods for age estimation. Dentin deposition has been measured according to various scoring systems, and the Pearson correlation coefficient with age has been found to be approximately 0.6. In the present study of 1000 teeth, molars excluded, secondary dentin was estimated according to three scoring systems. The teeth were prepared according to the half tooth technique. In addition, the area of the coronal pulp and the widths of the root and pulp chamber were measured in a stereomicroscope at the cemento-enamel junction and at three other defined points along the root. The Pearson correlation coefficient between age and secondary dentin varied in different types of teeth. Of the scoring systems, scores according to Johanson were most strongly correlated with age (r = 0.59 to 0.74). Correlation between age and the coronal pulp area varied from -0.47 to -0.72, and the range between age and ratio between pulp- and tooth width at the cemento-enamel junction was from -0.46 to -0.77. Correlations between age and ratio between sum of pulp widths and the sum of tooth widths for all four such measurements ranged from -0.58 to -0.81. Multiple regression analyses showed that by combining several types of measurements, the correlation with age was increased. A tendency was also observed towards reduced speed of secondary dentin formation in the elderly and in women.
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)
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