Mild - The white opaque areas in the enamel of the teeth are more extensive. Moderate - All enamel sufaces aces of the teeth are affected, and the surfaces subject to attrition show wear. Brown stain is frequently a disfiguring feature. Severe - All enamel surfaces are affected and hypoplasia is so marked that the general form of the tooth may be affected. The major diagnostic sign of this classification is discrete or confluent pitting.
Brown stains are widespread and teeth often present a corroded-like appearance.
In 1985, incidence of dental fluorosis ranged from 28 to 76 percent of U.S children aged 8 to 15. Moderate and severe forms of dental fluorosis were found to represent between five and six percent of the cases of fluorosis nationally. The estimated daily fluoride intake of a 44 lb. In A New Age, A History of the National Institute of Dental Research . Ruth Roy Harris.