Occlusion in the primary and early mixed dentitions in a group of Tanzanian and Finnish children.

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.