Confluent enamel pitting must be present for a tooth surface to be assigned a score of 7 on the TSIF scale (Table 4-3). In addition to the usual presence of dark brown staining, large areas of enamel may be missing and gross tooth structure may be altered as well. Thus, it has been sufficiently well documented that the most severe forms of enamel fluorosis for which classifications exist occur in children who reside in communities with water fluoride concentrations at or near the MCLG of 4 mg/L.
A third study, confined to the age range of 27-65 years, included a sample of 192 adults from Lordsburg, New Mexico, with a water fluoride concentration of 3.5 mg/L (Eklund et al. 1987). All members of this sample were native to Lordsburg and long-term residents of that community. The prevalence of severe fluorosis on Dean’s 1942 scale was extremely high in this sample, 76% overall. The investigators modified Dean’s scale specifically to split the “severe” category into ‘severe’ (discrete pitting) and ‘very severe’ (confluent pitting)” (Eklund et al. 1987). About half of those with more than moderate fluorosis were classified in the “very severe” category. These results for New Mexico adults are consistent with the results for children in Indiana and Illinois.
A reduction of all water fluoride concentrations to below 2 mg/L would be expected to make severe enamel fluorosis an extreme rarity in the United States, but would not be expected to eliminate it entirely. Isolated cases could still occur from excessive fluoride exposure from other sources, such as toothpaste swallowing and use of fluoride supplements and rinses. One can never rule out the possible existence of hypersusceptible individuals. Finally, though the ascertainment of severe enamel fluorosis is usually quite accurate in the United States, especially among children, it might be possible for dark yellow or brown staining and enamel pitting from other causes to be misdiagnosed as fluorosis. Such false positives might be particularly common among adults who are long-term users of smoked and smokeless tobacco products, heavy consumers of beverages such as coffee and tea, and perhaps some with special occupational exposures.
Studies show that facial attractiveness is important and that attractive people are judged to be more socially desirable than less attractive people (Berscheid and Walster 1974; Adams and Huston 1975; Adams 1977; Jenny and Proshek 1986). Newton et al. (2003) assessed the impact of modified images of untreated cavities on front teeth on the appraisal of personal characteristics in the United Kingdom. Study participants associated decayed and discolored teeth with lower intelligence and social competence and with poor psychological adjustment. Interestingly, the ratings depended on the facial appearance studied, an indication that the impact of enamel