Abstract
A survey comprising 478 children aged 6-7 yr and 13-14 yr was conducted in high F- areas (Wonji, 12.4 ppm F- and Awassa, 3.5 parts/10 F-) in the Rift Valley in Ethiopia. Dental fluorosis was found in 99% of the 6-7 yr old groups. Very mild to moderate fluorosis dominated in the primary teeth and moderate to severe fluorosis in the permanent teeth. All 13-14 yr old children born in Awassa or Wonji had fluorosis, mainly in the moderate-severe form. Of the 13-14 yr old children not born in the area, 84% 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 fibrosis more frequently had dental caries than teeth with no or very mild and mild fluorosis. The average DMFT [decayed, missing, filled teeth] 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 [Oral Hygiene Index] was 1.94 .+-. 0.71.