Journal of Dental Research, Vol 55, 189-195, Copyright © 1976 by International & American Associations for Dental Research Online Journals
Cusp size sexual dimorphism, and the heritability of maxillary molar cusp size in twins
R. H. Biggerstaff
The data given on the cusp size of maxillary first permanent and second
primary molars support the following conclusions. The qualitative
literature on cusp size hierarchy requires revision because the
quantitative data suggest that the mesiolingual cusp is largest, the
distobuccal cusp second largest, the mesiobuccal cusp third largest, and
the distolingual cusp smallest. Sexual dimorphism is apparent only when
reflected as a collective measure of total occlusal area, a summation of
cusp and ridge sizes. Antimere variations are random for individual cusps
and collective measures of total occlusal areas mask observable right-side,
left-side cuspal variations. Similarly, cross-twin and co-twin analyses of
cusp size heritability indicate a low level of hereditary variability.
