The purpose of this study was to investigate the differences of adult craniofacial structures as related to sex and malocclusion and to determine the distribution of such asymmetry with use of posteroanterior cephalograms. The data from each of seven measurements of 177 men and 38 women were entered onto a floppy disk compatible with an IBM personal computer; the statistical analysis system was used for calculation of univariate statistics and the production of bivariate plots. The results of the study showed that (1) posteroanterior parameters exhibited statistical differences between the sexes: specifically, in th e sagittal plane the dimension of the male skull is larger than that of the female; (2) the facial pattern deviated to the left side; and (3) asymmetry differed depending on the malocclusion.