Ages of eruption of the permanent teeth in Kenyan African and asian children.

Abstract

Mean ages of eruption of the permanent teeth (except 3rd molars) in African and Asian children were derived from a cross-sectional study of 2847 children aged 4-14 years, in selected nursery and primary schools in Nairobi, Kenya. Except for the premolars, the mandibular teeth erupted earlier than the maxillary ones in both races. The mandibular incisors and canines erupted earlier by 0.9-1.1 yr in Africans and 0.6-0.8 yr in Asians, and the molar by 0.2-0.4 yr in both races. The maxillary premolars were ahead of mandibular premolars by 0.1-0.2 yr in both races. The females were ahead of males in both races. Compared with the Asians, the African permanent teeth erupted earlier by 0.2-0.7 yr. The most frequent order of eruption in Africans is Mand I1, Mand M1, Max M1, Mand I2, and Max I1 between 5-7 years, while in the Asians the most frequent order is Mand M1, Mand I1, or Max M1, Max I1 and Mand I2 between 6-8 years. The incidence of Cusp of Carabelli in Africans and Asians is about 19-25%