Quantification of secondary dentine formation from orthopantomograms—a contribution to forensic age estimation methods in adults

The accuracy of most age determination methods in adults is unsatisfactory and therefore more precise methods are required. Teeth provide several useful points about an individuals age. With advancing age secondary dentine is deposited along the wall of the dental pulp chamber leading to a reduction in the size of the pulp cavity. These age-related changes can be determined and measured from dental radiographs. The aim of this study was to explore if measurements of the size of the pulp cavity performed on orthopantomograms can be used for individual age estimation. Measurements were made digitally for 6 types of teeth from orthopantomograms of 168 individuals aged between 14 and 81 years old. To compensate for errors due to the technique of radiography—for instance differences in angulation—ratios of distances were calculated: pulp/root length, pulp/tooth length and pulp/root width at three different root levels. The width ratios of the pulp cavity showed significant correlation to the chronological age and the coefficient of determination (r²) was highest in the upper lateral incisors (r²=0.913) when an exponential or a logistic regression model was constructed. At the same distance with a linear regression model the coefficient of determination (r²) reached 0.839.