Bolton discrepancy in a selected Canadian population.

摘要

Introduction. Bolton ratios are used to determine if the tooth structures in the two arches will allow ideal occlusion. The purpose of this study was to determine if the original Bolton ratios accurately describe Canadian Caucasians. Canadian Caucasian tooth widths have not been investigated to date. Methods. Ninety-seven models with ideal Class I occlusion as per the ABO index were randomly chosen from 3 Canadian sites (east coast, west coast and central Canada). The Bolton ratios, differences between and within the samples were calculated using the least squares means and the Student's t-test. Results. The Canadian ratios were not significantly different from the original Bolton ratios. However significant differences exist between the east coast and the west coast anterior Bolton ratios, and the west coast and the central Canada anterior Bolton ratios in the different samples (p0.05). Significant differences were found between and within the sexes for the overall Bolton ratios (p0.05). The maxillary lateral incisors and the maxillary left second premolar were the most variable in tooth width. Conclusions. The original Bolton ratios are applicable to Canadian Caucasian patients. However, the anterior ratios differ from region to region, and between and among the sexes. A significant portion of the Canadian population differed by more than 2 standard deviations from the original anterior Bolton ratio. A discrepancy of more than 3 mm in maxillary and mandibular tooth mass sums may be necessary to affect acceptability of orthodontic alignment. This study is the first to report the mesiodistal widths of teeth in Canadians and the most variation in tooth width was found in the maxillary lateral incisor.