Inter-arch tooth size discrepancy among different sagittal malocclusion groups and its clinical implications

ABSTRACT

The relationship of the mesiodistal widths of the maxillary and mandibular teeth influences the optimal final occlusion, overbite and overjet. The aim of this study was to compare inter-arch tooth size ratios among different malocclusion groups and to determine the percentage of clinically significant cases [outside two SD from the Bolton's mean] in each malocclusion group. Pretreatment records of 110 patients belonging to different malocclusion groups [Class I = 40, Class II = 40, Class III = 30] were evaluated for Bolton's anterior, overall and posterior ratios. Angle's classification system was used to assign cases into different malocclusion groups. No significant difference was found in anterior, posterior and overall Bolton's ratios among the three malocclusion groups. Forty percent of the entire sample had clinically significant discrepancy in anterior ratio, while 14.54% patients had discrepancy in overall ratios. In Class I malocclusion group, 37.5% patients had anterior ratios and 20% had overall ratios discrepancy outside 2 SD from Bolton's mean. In Class II group, 35% patients had anterior ratios and 12.5% had overall ratios outside this range. In Class III malocclusion group, 50% patients had anterior and 10% patients had overall ratio discrepancies outside 2 SD from Bolton's means. No significant difference was found between males and females when the three ratios were compared between the two genders in individual malocclusion groups as well as in the entire sample