A new system of dental age assessment.

A new method is given for estimating dental maturity or dental age, by reference to the radiological appearances of the 7 teeth on the left side of the mandible. Panoramic radiographs of 1446 boys and 1482 girls of French Canadian parentage have been used. Each tooth has been rated according to developmental criteria (amount of dentinal deposit, shape change of the pulp chamber, etc.) rather than changes in size. Eight stages, A to H, have been defined from the first appearance of calcified points to the closure of the apex. The method of Tanner, Whitehouse and Healy for skeletal maturity has been used for deriving a score for each stage of each tooth. The summed scores on all seven teeth give a dental maturity score which can be converted directly into a dental age. In case of missing teeth, the possibility of using combinations of different teeth is discussed.Although the maturity scoring system is probably universal in application, the conversion to dental age, or the location of the centiles for maturity at given ages, depends on the population considered. The present system is applicable from age 3 to 17; we hope to extend it to younger ages as material accumulates.