Tooth Size Discrepancy Of Angle’s Different Classes Of Malocclusion In Jimma Medical Center Dental Clinic Outpatients

Abstract

Executive Summary Background: Tooth-size discrepancy refers to unbalance between the mesiodistal widths of the maxillary and mandibular individual teeth or groups of teeth. For normal occlusion to occur, the maxillary and mandibular teeth must be proportional in size. Bolton’s ratios are a useful diagnostic tool used in clinical orthodontics to achieve ideal occlusion of the dentition for diagnosis and treatment planning. . Objective: To assess the Bolton’s anterior and overall tooth size discrepancy among different malocclusion groups in of Jimma medical center dental outpatients with 20 to 25 age groups Methods: Hospital-based cross sectional study was conducted in Jimma University medical Center, Dental OPD, in Jimma medical center dental outpatients. A total of 105 patients were recruited among 20 to 25 age groups. Inter arch tooth size discrepancy was assessed using patient study models and mesiodistal tooth width was measured with digital vernier calliper.One-way ANOVA was used to assess the Bolton ratio difference between the groups as function of Angle’s malocclusion and gender. The one sample t-test was used to compare the differences between the groups of the present study and Bolton’s original sample. Results: The differences in tooth size ratio of the study groups were not significant statistically, when the groups were compared on the basis of gender.A significant anterior tooth size discrepancy was observed in in the three classes. Statistically significant differences were exclusively observed between the study groups and Bolton’s original sample for the anterior ratio. The frequency of the clinically significant tooth size ratio discrepancy was lower for the overall ratio (35.2%) compared to the anterior ratio (58%). Conclusions: Bolton’s analysis shows the clinically significant anterior tooth size discrepancy was more prevalent than that of the overall ratio. In both anterior and overall tooth size discrepancy the incidence of mandibular excess is greater than maxillary excess. In both anterior and overall TSD, class III malocclusion had highest incidence.