Bolton's ratios and tooth-size discrepancies in a Nigerian population

Objective: The aim of this study was to determine the Bolton's ratios and tooth size discrepancies in a Nigerian population. Method: The Bolton tooth size analysis was performed on 54 dental casts of Nigerian subjects comprising 33 (61%) males and 21 (39%) females (mean 26.6 ± 2.1 years). The overall and anterior tooth size ratios were determined, and gender differences among the sample population was evaluated with t-test. The frequency and magnitude of deviation of the Nigerian subjects outside 2 standard deviations from the Bolton's mean was also determined. Result: The result revealed no statistically significant gender differences in interarch tooth size ratios (p> 0.05) and the measurement for both males and females were therefore combined. The overall ratio was 92.1% ± 2.35 and anterior ratio was 78.9% ± 2.64. The overall tooth size discrepancy was present in 9.3% and the 25.9% of the subjects had anterior tooth size discrepancy in relations to more than 2 standard deviations from the Bolton's mean values. Conclusion: The study provided data on tooth size ratios among Nigerian subjects whose values were larger than Bolton's data. This study re-emphasized the importance of developing standards for each population. Key words: Tooth size discrepancy, Bolton’s ratios,