The aim of the study was to define the developmental stage of the mandibular premolar roots at different ages. The study was performed on a sample of 500 orthopantomographs taken from children aged between 6 and 14 years (236 boys and 264 girls), all of whom were orthodontic patients in Clinic of Stomatology, Nish. We used a method by Gleiser and Hunt and modification by Tijanic (1981) to analyse the developmental stages of the mandibular premolar roots (P1 and P2) as well as the symmetry of their development on both sides. The results indicate the following : three different stages are present at the age of 7. Stage 6 is most present for P1, stage 5 for P2 , with minor gender differences. At the age of 8, the stages most present in both genders are stage 6 for P1, and stage 5 for P2. At the age of 9, the stages most present in both genders are stage 7 for P1 and stage 6 for P2. At the age of 10, stage 7 is most present for both premolars (P1 and P2). Stage 8 is most present for P1 in boys aged 11, therefore stages 8 and 9 are present equally in girls of the same age. At the age of 11, stage 7 is dominating in boys, that is, stage 8 in girls. At the age of 12, stage 9 is most present for P1 in both genders and for P2 in boys, although stage 8 is common in girls aged 12. Higher developmental stages of the mandibular premolar roots are present within certain age categories in girls, except the ages of 7 and 8, at which they are present equally in both genders. Asymmetric development of the man dibular premolar roots is more present at the ages of 9 and 10. Our results indicate the higher dental age of the mandibular premolar roots in girls, when compared to boys of the same age. .
