Craniofacial differences between Japanese and British Caucasian females with a skeletal Class III malocclusion

The racial differences in the craniofacial structures of 28 Japanese and 24 British Caucasian females with Class III malocclusions associated with a severe skeletal pattern were examined using lateral cephalograms. The mean age of the Japanese and Caucasian patients was 19.6 +/- 3.5 and 20.2 +/- 3.8 years (+/- SD), respectively. The mean values of 14 linear and 13 angular cephalometric parameters were compared between the two groups. The results showed that the Japanese females had a significantly reduced anterior cranial base (P < 0.01), a more retrusive midfacial component (P < 0.05), and a significantly increased lower anterior facial height (P < 0.01) associated with a more obtuse gonial angle (P < 0.05) compared with the Caucasians. Analysis of the dento-alveolar component in Japanese patients indicated more proclined upper incisors (P < 0.01) compared with those of Caucasian subjects. The reduced anterior cranial base and midfacial component, and the high-angle facial pattern in the Japanese population, may be morphological features based on race, and these skeletal features seem to be less favourable for a skeletal Class III growth pattern compared with the Caucasian population.