Chronological age determination based on the root development of a single third molar: a retrospective study based on 2513 OPGs.

The aim of this survey was to correlate chronological age with the root development of only one third molar using a sample of 2513 subjects of Belgian Caucasian origin within the age range of late 15 to 22 years. Observations were performed by two observers, who were calibrated for intra- and inter-rater reliability by means of Kappa statistics and each third molar present was scored according to the modified method of Gleiser and Hunt. The method used in this study delivered linear regression formulae based on a sole wisdom tooth, divided according to gender. The results revealed standard deviations similar to those reported in comparable publications and even to those calculated with other skeletal age calculation techniques.