On the groove configuration of mandibular molars: The unreliability of the “dryopithecus pattern” and a new method for classifying mandibular molars

The long-used qualitative nomenclature for the cusp-groove pattern of lower molars, and the definition applying to it, was investigated and found to be unsatisfactory for the repetitive classification of lower molars. Moreover, developmental grooves per se were found to represent the results of highly variable environmental phenomena and therefore their use cannot be justified as an evolutionary determinant. A simple, but effective classification for lower molars, based on cusp size, cusp number, distal fovea, and distal marginal ridge was presented.