Dental findings in high-fluoride areas in Ethiopia.

A survey comprising 478 children aged 6-7 years and 13-14 years was conducted in high-fluoride areas (Wonji, 12.4 parts/10(6) F- and Awassa, 3.5 parts/10 F-) in the Rift Valley in Ethiopia. Dental fluorosis was found in 99% of the 6-7-year-old groups. Very mild to moderate fluorosis dominated in the primary teeth and moderate to severe fluorosis in the permanent teeth. All 13-14-year-old children born in Awassa of Wonji had fluorosis, mainly in the moderate to severe form. Eighty-four percent of the 13-14-year-old children not born in the area had fluorosis, mainly in the very mild form. The most severe fluorosis was seen in the last erupting teeth, but moderate fluorosis was also seen in primary incisors, indicating placental transfer of fluorides. Teeth with moderate and severe fluorosis more frequently had dental caries than teeth with no or very mild and mild fluorosis. The average DMFT was 2.46 +/- 2.34 in Wonji and 1.69 +/- 1.88 in Awassa. The average dft was 0.32 +/- 0.80 in Wonji and 0.40 +/- 0.96 in Awassa. Gingivitis was seen in 97% of the children and the average OHI-S was 1.94 +/- 0.71.