Staaf V, Mornstad H, Welander U; Age estimation based on tooth development; a test of reliability and vahdity. ScandJ Dent Res 1991; 99; 281-6.Abstract -The precision and accuracy of three commonly used methods for age determination by teeth were studied in 541 children aged 5.5-14.5 yr. These methods rely on estimation of tooth development as seen in radiographs compared with compiled dental charts. It was found that charts made from Scandinavian populations gave a rather good precision, while one from a Canadian population gave a consistent overestimate. Dependent on the method used, sex, and age, the 95% confidence interval for an individual prediction could be more than + 2 yr.

The common methods of age determination with the aid of teeth have been criticized because they rely on subjective estimations of tooth development, as seen in radiographs, and subsequent comparisons with pictures and descriptions in compiled dental charts. The distribution around an estimated age with these methods is usually more than ±2 yr between the 10th and 90th percentiles. In an attempt to avoid subjective estimations, objective measurements of developing teeth were correlated with subjects' chronologic ages. The structures measured were crown height, apex width, and root length. With the aid of a multiple regression model, a linear relationship between some of these distances and age was shown. The distances which were best correlated with age differed according to sex and age. This method has a 95% C.I. of about ±2 yr around an estimated age. It therefore seems to be more accurate than the earlier methods. Thus, the individual variation in tooth development is of the same order of magnitude, and a better estimation can therefore not be done in children 6–14 yr of age.