[Evaluation of simple method to predict the anterior and overall bolton discrepancy in a south Iranian population]

Bolton analysis is a good indicator to evaluate tooth size discrepancies but the ethnic variation of these values should be considered. Thus, the aim of this study was to determine the tooth ratios in different sexes and malocclusion groups in Iranian population and to compare these ratios with the data from the Bolton study. Also the best predictors of anterior and overall Bolton discrepancies were determined in this study. In this cross-sectional study, a total of 715 dental casts [526 female. 189 male] were recruited from department of orthodontics of Shiraz dental school and private offices of orthodontists. The samples were divided into three groups based on Angles Malocclusion groups. Then the greatest mesiodistal widths of all teeth were measured with digital caliper with accuracy of 0.01 mm and the anterior and overall ratios were calculated. Finally, the data were analyzed by Pearson Correlation, independent t-test and Kruskal-Wallis test, through SPSS software. The anterior ratio [78.74%] and the overall ratio [91.94%] showed no statistically significant differences according to sex and malocclusion groups in south Iranian population. The results revealed that the correlation coefficient of lateral ratio with anterior Bolton discrepancy was 0.544 and central ratio with anterior Bolton discrepancy was 0.536. Also the correlation coefficient of first premolar ratio with overall Bolton discrepancy was 0.440 and the second premolar ratio with overall Bolton discrepancy was 0.407. The anterior ratio for the whole population was statistically different from Bolton's, but no statistically significant difference was found for the overall ratio. In Iranian population, the best predictor of anterior Bolton discrepancy was lateral tooth and the best predictor of overall Bolton discrepancy was first premolar