Fluorosis of deciduous teeth and first permanent molars in a rural Kenyan community.

The severity and distribution of fluorosis in the deciduous dentition of 76 children in a low-income community near Nairobi were studied. Seventeen children comprised a low-F (fluoride) group (water less than 0.7 ppm F) and 59 a high-F group (water approximately 9 ppm F). The high-F group had scores greater than or equal to 5 in the Thylstrup & Fejerskov classification system for 29% of the deciduous tooth surfaces, compared with 7% in the low-F group. Comparison between the scores of the second deciduous and the first permanent molars showed no significant difference in the high-F group (p greater than 0.001), whereas the deciduous molar was significantly less severely affected in the low-F group (p less than 0.001). The deciduous molars of the two groups differed significantly (p less than 0.002), but not the permanent molars (p greater than 0.10). Early introduction of tea might have been a major contributor to the distributions of fluorosis, particularly in the low-F group.