“…Since the human tooth continues to develop postnatally, the pattern of fluoride distribution throughout the full spectrum of enamel development in this tooth is, there fore, still to be established. However, the pattern of fluoride distribution that appears to emerge from those 7 human fetal teeth available for analysis seems to be somewhat similar, in the comparable stages of devel opment, to that reported in studies of devel oping rat and bovine [Weatherell et al, 1975] and pig incisors [Speirs, 1975[Speirs, ,1978a. As in these previous reports, the fluoride concentrations in the human teeth fell as the partially mineralized enamel increased in thickness during the period of matrix secre tion.…”