Applicability of Bolton tooth-size ratios in racial groups.

AIM: To determine whether there is sexual dimorphism regarding Bolton ratios within four ethnic groups and to compare them against Bolton standards.

METHODS: The sample consisted of 140 dental study casts of untreated normal occlusion subjects, derived from four racial groups: black, white, Afro-Mediterranean, and Japanese. Anterior and overall Bolton ratios were calculated for each cast. The Kolmogorov-Smirnov test, t test, and one-way ANOVA were used.

RESULTS: No statistically significant sexual dimorphism in anterior or total tooth-size ratios were found within any group. Only the Japanese anterior ratio (75.09) was statistically less than the Bolton standard (77.2; P<.001).

CONCLUSION: The Bolton ratio can be applied to the investigated ethnic groups except for the anterior ratio in Japanese patients.