Thylstrup A
Scand J Dent Res. 1983 Aug;91(4):243-6. doi: 10.1111/j.1600-0722.1983.tb00810.x.
A 6-yr-old Danish girl born and reared in a high fluoride area in Kenya was examined for a period of 1 1/2 yr during which a permanent maxillary central incisor erupted. Present primary and permanent teeth showed obvious dental fluorosis with isolated pits on primary molars. At the time of eruption the crown of the permanent central incisor had its normal anatomical shape. Isolated and confluent pits began to develop about the time of complete eruption. The observations thus confirm previous theories suggesting that pits in fluorosed enamel are secondarily produced defects of traumatic origin.