Tooth-size discrepancies among different occlusion groups of southern Chinese children.

The purpose of this study was to compare Bolton anterior and overall ratios among different occlusion groups of southern Chinese children. Fifty plaster casts with Class I occlusion, 30 with Class II occlusion, and 30 with Class III occlusion were selected from a random sample of 1247 12-year-old southern Chinese children in early permanent dentition in Hong Kong. For the anterior ratio, a statistically significant difference was found between the Bolton standard and the Class III occlusion group. For the overall ratio, statistically significant differences were found between the Bolton standard and the Class II occlusion group, and between the Class II and the Class III occlusion groups. Thus specific standards are required for Class II and Class III cases from the southern Chinese population.