Safety l Fluoridation Facts 51 In reviewing this report,75 it should be noted that dental fluorosis was not assessed in NHANES 1988- 1994 and so it was not possible to compare the NHANES 1999-2002 to the earlier NHANES report. The only other previously collected national data on dental fluorosis were the 1986-1987 National Institute of Dental Research (NIDR) National Survey of Oral Health in U.S. School Children. Differences in study design between NIDR 1986-1987 and NHANES 1999-2002 should be considered when drawing inferences about changes in prevalence and severity of enamel fluorosis.75 Examples of differences in these two surveys include but are not limited to: • NIDR survey is a school-based survey while the NHANES is a household survey. • NHANES did not collect residential histories NIDR did gather residential histories but it is unknown if NIDR reported dental fluorosis data only for those with a single residence history. • NIDR collected water samples from schools for fluoride analysis NHANES did not collect water samples for analysis until the 2013-14 survey cycle. As defined in Table 3, very mild dental fluorosis is characterized by small opaque, paper-white areas covering less than 25% of the tooth surface. The risk of teeth forming with the very mildest form of dental fluorosis must be weighed against the benefit that the individual will have fewer cavities thus saving dental treatment costs, avoiding patient discomfort and reducing tooth loss.81,82 In addition, the risk of dental fluorosis can be viewed as an alternative to having tooth decay,83 which is a disease that causes cosmetic problems, pain, missed school and work, and can lead to infection and, in advanced cases, life-threatening health effects. This is in contrast to dental fluorosis which is not a disease and is not life-threatening. The risk of teeth forming with the very mildest form of dental fluorosis must be weighed against the benefit that the individual will have fewer cavities thus saving dental treatment costs, avoiding patient discomfort and reducing tooth loss. Table 3. Dental Fluorosis Classification by H.T. Dean – 194275 Classification Criteria-Description of Enamel Normal Smooth, glossy, pale creamy-white translucent surface Questionable A few white flecks or white spots Very Mild Small opaque, paper-white areas covering less than 25% of the tooth surface Mild Opaque white areas covering less than 50% of the tooth surface Moderate All tooth surfaces affected marked wear on biting surfaces brown stain may be present Severe All tooth surfaces affected discrete or confluent pitting brown stain prsent