Mesiodistal crown dimension of the permanent dentition of American Negroes.

A study of the mesiodistal crown dimension was conducted on the teeth of 162 American Negroes, equally divided between males and females. A total of 3,980 teeth were measured. Teeth were measured from the plaster casts by means of Boley gauges. The sample was drawn from a growth study, private practice, and a dental clinic. The mean width of the teeth of males and females was reported. The teeth of males were larger than those of females for each type of tooth in both arches, although they exhibited a similar pattern of tooth size. The maxillary first premolars were larger than the second premolars, while the mandibular second premolars were larger than the first premolars. The first molars were larger than the second molars in both the maxillary and mandibular arches in both sexes. The ratio of the mandibular dentition ot the maxillary dentition was 94 per cent in both sexes. The ratio of the sum of the widths of the canines and incisors of the mandibular dentition to those of the maxillary dentition was 77 per cent. Also, the ratio of the mandibular incisors to the maxillary incisors was 71 per cent in both sexes.