Relation between the Stages of Root Calcification of Third Molars and Chronological Age of Peruvian People from 13 to 23 Years Old

This study investigated the relationship between chronological age and third molar root development for a Peruvian population. In this retrospective analytical study, the sample comprised 1367 panoramic radiographs from people of known chronological age and sex. The root development was classified through Demirjian’s stages. Intra-observer agreement was determined using Kappa statistics. Simple and multiple linear regression was used to predict the chronological age from the root development of the third molars. Symmetry in root development of right and left third molars within the same jaw was 78.54% (Kappa: 0.72; p˂0.05). However, there was only 57.94% concordance between the maxillary and mandibular third molars (Kappa: 0.47). Root formation was completed earlier in males than in females, in stages F, G and H. The probability that a person was at least 18 years old was high when their third molars were completely formed (stage H), and there was an increased probability that subjects with root development between stages A and E were underage. These empirical probabilities and regression formulas can be provided for forensic and médicolegal purposes. The mean difference between chronological and dental age was about 1.50 years when any molar was used, this difference decreased to 1.39 years when four molars were assessed.