Abstract: Studies of the molar crown basal area and relative basal cusp area in human evolutionary research has been important but it has been difficult to measure precisely the occlusal or cusp areas of the teeth. In recent years, advances in computer technology have made it possible to quantify some of these complex traits. With the combination of digital photography and advanced computer software, two non-linear morphologies, absolute occlusal area and relative basal cusp area ( RBCA) , of maxillary and mandibular molars of recent Northern Chinese have been quantified. From the results of this research, the following conclusions are made: the gradation protocone> paracone> metacone> entocone as noted in any one of the maxillary molars, while the RBCAs display various sequences in the three mandibular molars; the metacone and protocone of the maxillary molars shows a clear allometric tendency; the RBCAs variability is collectively higher in the mandibular molars than in the maxillary molars, distal cusps rather than mesial cusps, and increases from M1 to M3. This research investigated the molar RBCAs of modern Chinese for the first time and now provides fundamental data for future application in palaeoanthropological and physical anthropological work.

Key words: Molar; Crown basal area; Relative basal cusp area; Morphometrics; Recent Northern Chinese