The Effect of Partial Defluoridation of a Water Supply on Dental Fluorosis--results after 11 Years.

A EARLY as 1901, the condition now called dental fluorosis or mottled enamel was described in a letter written by J. M. Eager, a medical officer stationed in Naples, Italy, who reported its presence among Italian emigrants.' The term "mottled enamel" was first used by Dr. G. V. Black in a series of articles published jointly with Dr. Frederick S. McKay2'3 in which the lesions were described in detail. Many papers followed which reported the widespread prevalence of dental fluorosis in this country and abroad.4-6 Because the condition occurred in such well defined geographical districts, dental fluorosis soon was associated with the lack or overabundance of some agent in the water supply.7'8 However, initial investigations, utilizing standard water analysis methods, failed to identify the causative agent. It was not until 1931 that three investigators, working independently, established the direct relationship between mottled enamel and the fluoride content of water.9-11 Dental fluorosis is a disease which affects the structure and appearance of enamel. Nearly every child born and raised in an endemic area, who regularly consumes the water containing excessive amounts of fluoride, is certain to be afflicted in some degree. In its milder forms dental fluorosis is characterized by opaque, paper white areas scattered irregularly over surfaces of the teeth.'2 More severely affected teeth demonstrate pitting, unsightly brown to black staining and, often, a corroded appearance which represents a confluence of hypoplastic areas. Teeth so affected are prone to attrition and, thus, early loss. Following the discovery of the etiologic agent for dental fluorosis, it was found that the disease did not occur during the lifetime of persons who drank water free from excessive concentrations of fluoride from birth to eight years of age,13"14 the period during which most permanent tooth calcification takes place. It is not always feasible or practical, however, for a community