The aim of the study is to define the variability of number of basic cusps on first and second upper molars (M1 and M2) in children of Niš, aged between 12 and 18. We have utilized the method by Cope-Osborn for marking basic cusps (Pa, Pr, Me and Hy). 400 study models - 164 male and 236 female orthodontic patients - were analyzed at the Clinic of Stomatology, Niš. We described them as M14 and M24 types (with crowns having four basic cusps) and M23 (with crowns having only three basic cusps). M14 crown types are found in all examinees, whereas 70.50% of examinees have the type M24, out of which 69.51% are males, and 71.19% females. The type M23, with Hy affected by reduction process on M2, is found in 29.50% of examinees, almost equally present in males (30.49%) and females (28.81%). Associative superspecialized formation - Tuberculum Carabelli (T.C.) on M1 is found in 31.25% of examinees, mostly males (40.85%).
