Two high and two low socioeconomic areas were selected for the Tanzanian portion of this study, with all nursery schools located in those areas included, for a subtotal of 580 children. The Finnish group was comprised of a total of 575 Caucasian children examined. The Tanzanian children (83 percent Black African, 10 percent Asian, 7 percent Arab) had fewer occlusal anomalies than the Finnish children did. Finnish children had a 13-percent incidence rate of lateral cross-bite; among African children, 8 percent showed anterior crossbite; and among the combined Asian/Arab group of children, 10 percent had an anterior open bite. African children had significantly fewer prevalences of distal bite, lateral crossbite and crowding than Finnish children did.