Racial variation of cephalometric measurements in Hawaii.

To establish the race-specific norms and investigate the underlying etiological basis of racial differences in malocclusion, cephalometric measurements of Steiner were analyzed for five major racial groups in Hawaii: Caucasians, Japanese, Chinese, Filipinos, and Hawaiians. Subjects consisted of 210 healthy and orthodontically normal individuals of both sexes aged 15 years or older. Analysis of age- and sex-adjusted cephalometric values showed that bone-to-bone relationships are largely comparable among races with an exception of GoGn/SN. Significant racial differences are incisal inclinations in relation to the maxilla, the mandible, or the opposite incisors, with the least inclination for Caucasians and the greatest for Chinese. The result is general tendency of bimaxillary protrusion of non-Caucasians. No significant differences were detected in arch lengths of both jaws among these groups. It is suggested that the observed higher prevalence of mesioclusion in non-Caucasians--especially Orientals--is due to an imbalance of tooth dimension to the alveolar bone.