Evaluation of Tooth Size Discrepancy and Bolton Tooth Size Analysis in Different Angle’s Malocclusion Groups: A Retrospective Study

Abstract

Background and aim: The tooth size discrepancy (TSD) is crucial in determining and predicting treatment outcomes. The Bolton analysis, which measures the mesiodistal width of the mandibular and maxillary teeth, is essential for this process. This study aims to evaluate the Bolton anterior and overall tooth size ratios and to analyze their association with various classes of dental malocclusion, as defined by Angle’s classification. Methods: In this retrospective cross-sectional study, 150 patients with complete permanent dentition and no dental anomalies were randomly selected. After excluding unsuitable casts, samples were divided into Class I, II, and III malocclusion groups. Anterior and overall Bolton ratios were measured and analyzed across groups, and gender differences were also evaluated. Results: The present study showed that skeletal Class III patients had significantly higher anterior Bolton ratios than Class II patients. However, this difference was not statistically significant in the CLI group, although it was greater. Although the differences in overall Bolton ratios between different malocclusion groups were not statistically significant. Statistical analysis showed that there was a weak correlation between these parameters and anterior Bolton ratios. About 30% of patients had significant anterior tooth size differences (more than 1 standard deviation from the Bolton standard). In this study, there was no significant difference in anterior and overall Bolton ratios between the male and female groups. Conclusion: This study revealed that skeletal Class III patients had a significantly higher anterior Bolton ratio than Class II patients. There was no significant difference in overall Bolton ratios between different malocclusion groups, and there was no significant difference in anterior and overall Bolton ratios between males and females in general.