Two criteria are used in the classification of lower molars: the number of cusps and the shape of intercusp patterns, based on the protoconid-entoconid contact. The shape of notches between the present cusps has been of a great interest to anthropologists. There are three types of intercusp contact patterns: 'y' as the basic or proto-form, '+' and 'x' forms. The 'y' form was best developed in the Dryopithecus, so it is named after this fossil ape. The research was conducted in 757 orthodontic patients from Niš, with the aim of determining the frequency of cusp numbers and the types of intercusp patterns in the mandibular M1 and M2 teeth. In M1, 5 cusps are the most frequent (72,52%), 4 cusps appear in 26%, while 6 cusps are sporadic (0,8%). In M2, 96% have 4 cusps and 4% have 5 cusps. The 'y' type is dominant in M1 (66,58%) and the '+' type in M2 (91,37%). For M1, the 'y5' type is characteristic in 65% and the '+4' type in 22%. In a dominant number of patients (90%), M2 is characterized by the combination '+4', while the 'y5' form is found only in 3%. .
