Comparison of Bolton’s anterior tooth size discrepancy in angle’s Class I and Class II malocclusion in dakshina kannada population

Background: Interarch tooth size relationships differ between populations because differences in tooth sizes are not systematic. Population and gender differences in maxillary tooth size may not be the same as the differences in mandibular tooth size; hence, different interarch relations might be expected. Objective: The objective was to compare anterior tooth size discrepancies in Angles Class I and Class II malocclusions with Bolton standards and evaluate its effect on gender in a sample of Dakshina Kannada population who underwent orthodontic treatment. Methods: The study sample consisted of 203 pretreatment study casts, which were selected from records of orthodontic patients, who were residents of Dakshina Kannada, Karnataka. Subjects were divided into two groups: Group I (Angle's Class I, n = 108), Group II (Angle's Class II, n = 95) according to Angle's classification of malocclusion. The mesiodistal widths of all maxillary and mandibular teeth from right canine to left canine were measured with a digital caliper to calculate the Bolton ratio. The readings were then used to compute the anterior Bolton ratios. Chi square test was used for the statistical analysis. Results: A mean anterior Bolton ratio of 77.78± 4.31 for class I malocclusion group and a mean anterior Bolton ratio of 78.3± 4.52 for class II malocclusion group were found for the sample, The anterior ratio was found to be statistically insignificant when compared to the Bolton’s norm of 77.2 ± 1.65 (P>0.1724). Comparison between gender and the different malocclusion groups for the anterior ratio revealed no statistically significant difference. Conclusion: From analyzing the data, it was found that there was no significance between Bolton’s norms and type of malocclusion in Dakshina Kannada population. No significant relationship between gender and type of malocclusion was observed.