A Study of Cusp Base Areas in the Maxillary Permanent Molars of American Whites

The focus of this descriptive study was toexplore the patterns of variation of base crown areas forthe four major cusps on the maxillary first and secondpermanent molars in a cohort of contemporary NorthAmerican whites of western European descent. Acomputer-assisted photogrammetric method was usedto measure two-dimensional areas of the cusps. Rankingof mean cusp size was the same for M1 and M2, namelyprotocone > paracone > metacone > hypocone. In concertwith field theory, size decreased while variability (CV)increased across this same sequence. Overall area of M1(97 mm2) is 13% larger than M2 (86 mm2) in this sample.Most cusps exhibited significant sexual dimorphism,with greater differences for the distal cusps within atooth and from M1 to M2. Intercorrelations of cusp areaswere notably low (r2 < 15%) both within and betweenM1 and M2, suggesting considerable independence informative rates of each cusp and low morphologicalintegration of these constituents of the occlusal table.Limited comparative material in the literature suggeststhat cusp areas may valuably extend the quantitativecomparisons for genetic and biological studies beyondconventional tooth crown width and length.