Dentition and occlusion development in African American children: mesiodistal crown diameters and tooth-size ratios of primary teeth.

PURPOSE The aim of this study was to evaluate the mesiodistal primary tooth size diameter and posterior sagittal tooth-size ratio in an African American population and compare to existing African American and European American norms. METHODS A sample of 1,124 African American children, 564 males and 560 females, was used to record crown size diameters employing indirect (cast) and direct (intraoral) measurement techniques. RESULTS African American males showed larger crown diameters than African American females for each of the 5 classes of primary teeth (a=0.05 level). Sexual dimorphism averaged 3.5% in the maxilla and 3.2% in the mandible. When inter-racial primary crown size comparisons were made between African American and European American children, African American males showed larger mean crown diameters for each class of primary teeth compared to European American males. The inter-racial comparisons in crown diameters of females showed fewer statistically significant differences in primary teeth classes. When crown size comparisons of the primary dentition's posterior segments were made, African American males and females showed a larger primary posterior sagittal tooth-size-ratio compared to European American children. CONCLUSIONS While intra- and inter-racial sex differences exist in the primary teeth of African American and European American children, with few exceptions, the mesiodistal crown size differences and sexual dimorphism appear to be larger for the African American population. African American children show a larger primary posterior sagittal tooth-size ratio (0.96) compared to European American children (0.94).