Shed deciduous canines and molars were obtained from 9-to 10-year-old schoolchildren in Uppsala (about 1.2 ppm water F) who, during their first year of life, had been either typically breast-fed or formula-fed and in the latter case had received a much greater F supply. While cervical enamel and dentine practically always had higher F contents than the occlusal counterparts, the formula-fed children had about a 2–3 times higher F content in both occlusal and cervical tissues than the breast-fed childre