Aims: To (1) establish tooth-size ratios in a Saudi sample with Class I normal occlusion; (2) compare tooth-size ratios between the present study and Boltonís study and between genders; and (3) investigate whether there was a correlation between the interincisal angle and the anterior ratio. Material and Methods: Dental casts and cephalometric radiographs of 65 subjects (37 males and 28 females) were used in this study. The age range was 18 to 25 years. All subjects had normal Class I occlusion, with no history of orthodontic treatment. Results: Studentís t test was used to compare tooth-size ratios between the present study and the Bolton study, and between genders. Pearsonís correlation coefficient was computed between the anterior ratio and interincisal angle. Results indicate that there were no statistically significant differences between the mean values of the anterior ratio and the overall ratio of the present study and the mean values reported by Bolton and also between genders. Further, the results revealed a low correlation between the anterior ratio and the interincisal angle. Conclusion: It is suggested that Boltonís prediction tables can be used for Saudis until a large enough representative sample is studied to allow the drawing of prediction tables.
World J Orthod 2005;6:289Ė295.