Comparison of Bolton's Ratio for Evaluation of Tooth Size Discrepancy between Maxillary and Mandibular Arches in Vidarbha Population

BACKGROUND Bolton's ratio is an indispensable parameter used in orthodontic diagnosis to evaluate the tooth size discrepancy. However, these norms have been established for Caucasian population and population variations necessitate the evaluation of these ratios for Vidarbha population. The objectives of the present study were to determine Bolton's ratio for Vidarbha population, compare them with original Bolton's ratios and determine the clinical significance of these differences. METHODS The study sample consisted of study casts of 300 subjects in the age range of 18-30 years, all belonging to Vidarbha population, having a full complement of teeth. Tooth dimensions were measured using digital vernier caliper and Bolton's overall ratio and anterior were calculated. The data calculated was statistically analysed for range, mean, standard deviation and coefficient of variation. Unpaired t-test was applied to draw a difference between the results of this study and the results from Bolton's study. RESULTS Bolton's overall and anterior ratio norms for Vidarbha population sample were found to be 88.15 and 78.50, respectively, with standard deviation of 3.27 and 3.19, respectively. The range of overall ratio noted was 80.36-98.44, and the range of anterior ratio was 67.74-89.70. CONCLUSIONS In general, the values obtained from this study for the Vidarbha population differ from the data of Caucasian population. So, it can be inferred that the established Bolton's values for Caucasians cannot be used for the Vidarbha population. Hence, population specific standards are necessary for clinical assessment.