Applicability of Boltons Analysis in Normal Occlusion and Class II Division 1 Malocclusion in North Indian Population

Abstract

Objective: The study was designed to evaluate and compare the tooth size ratios of a North Indian population to the Bolton ratios, and determine any gender-based differences in tooth-size ratios. Subjects and Methods: Forty samples with normal occlusion and forty patients with Class II division 1 malocclusion were randomly selected with the age range of 13 to 25 years equally divided among males and females. The mesiodistal crown dimension was measured using a digital caliper accurate to 0.01 mm. For statistical evaluation, descriptive statistics and Student’s t-test were performed. Results: The anterior ratio and overall ratio of the present study did not show any significant differences from that of mean values reported by Bolton for normal occlusion. The overall ratio showed statistically significant differences (p <0.05) between normal occlusion and Class II division 1 malocclusion groups. The tooth most closely related to the overall ratio in the Class II division 1 malocclusion group was the mandibular second premolar. Conclusion: The results of this study show that the overall and anterior Bolton ratios can be applied with confidence to an Indian population. There is a tendency for maxillary tooth size excess in the Class II division 1 malocclusion patients of the same population. It can be concluded that Bolton tooth size analysis is an important diagnostic tool and should be taken into consideration before the initiation of orthodontic treatment.