Dental Fluorosis over Time: A comparison of National Health and Nutrition Examination Survey data from 2001-2002 and 2011-2012.

Purpose: Excessive fluoride ingestion has been associated with dental fluorosis. The purpose of this study was to determine if there was a difference in dental fluorosis prevalence comparing National Health and Nutrition Examination Survey (NHANES) trend data for adolescents, aged 16 and 17 years, when compared to data collected in 2001-2002 to data from 2011-2012.
Methods: The sample included 875 participants. Data analyses included Chi square tests and logistic regressions. The data were from a nationally representative survey by calibrated dental examiners using the modified Dean's fluorosis classification system. The data analysis of the prevalence of fluorosis severity level was dichotomized to very mild/above vs. normal/questionable.
Results: In 2001-2002, the weighted percentage prevalence of the denoted dental fluorosis categories were: 49.8% normal (i.e., unaffected), 20.5% questionable, and 29.7% very mild and above. In 2011-2012, the weighted percentage prevalence categories were: 31.2% normal, 7.5% questionable, and 61.3% very mild and above. When comparing years 2001-2002 with the years 2011-2012, the prevalence of very mild and above fluorosis increased by 31.6% (P <.0001) for the 2011-2012 group. In adjusted logistic regression, participants from the years 2011-2012 were more likely to have very mild and above dental fluorosis than participants in 2001-2002 as compared with normal/questionable fluorosis (Adjusted odds ratio= 3.85; 95% confidence interval= 2.20, 6.72; P <.0001).
Conclusion: There was a difference of 31.6% in dental fluorosis prevalence between 2012-2011 when compared to data from 2002-2001 in adolescents aged 16 and 17 years. The continued increase in fluorosis rates in the U.S. indicates that additional measures need to be implemented to reduce its prevalence.