Bolton analysis and Angle´s Class I, II and III maloclusions

Objectives: The aim of this study was to evaluate the correlation between the tooth size discrepancy and Angle Class I, II and III maloclusions by Bolton analysis. Methods: The mesio-distal size of the superior and inferior teeth from 60 patients casts from the Orthodontic Department, Faculty of Dentistry, University of Rio de Janeiro was measured by two evaluators. The casts were divided according Angle’s classification: Class I (n=20), Class II (n=20) e Class III (n=20). The measurements were written in standardized cards to facilitate Bolton analysis (total and anterior). Twelve casts were measured twice by each evaluator to verify the method error and the Pearson correlation test were used to analyze the evaluator’s calibration. The statistical tests used were Chi-square and Kruskal-Wallis. Results: The means and standard deviation from the total superior, total inferior, anterior superior, anterior inferior teeth size discrepancies were: Class I – 0.96mm ± 0.69, 2.23mm ± 1.23, 1.1mm ± 0.41 and 1.48mm ± 1.39; Class II – 1.36mm ± 0.90, 2.31mm ± 1.3, 1.3mm ± 0.57 and 1.39mm ± 1.08; Class III – 1.5mm ± 1.2, 2.08mm ± 1.49, 1.11mm ± 0.62 and 1.7mm ± 0.97. There were no statistical significance between the means. Conclusions: there was no correlation between the tooth size discrepancy and Angle Class I, II and III maloclusions.