Dental fluorosis, dental caries, and oral health related quality of life (OHRQoL) in the United States
MetadataShow full item record
OBJECTIVES: This study has three aims: 1) to determine the trends and prevalence of dental fluorosis and caries among persons aged 6-19; 2) to examine the association between dental fluorosis and caries among persons of the same age group; and 3) to investigate the influence of dental fluorosis and caries on oral health-related quality of life (OHRQoL) among people aged 16-49 in the United States. METHODS: The data from the National Health and Nutrition Examination Survey (NHANES) 1999-2004 and 2011-2012 were analyzed. For aims 1) and 2), individuals aged 6-19 years, who completed the home interview and oral health examination were included (n=9,493, n=2,411, respectively). For aim 3, the data from NHANES 2003-2004 were analyzed including only people aged 16-49, who completed the home interview and both conditions examination (n=3,035). The reason behind age restriction is that people aged 16-49 were targeted to answer OHRQoL questions. Dental fluorosis was measured by Dean’s Index (6-categories of severity), where classification was based on the two teeth most affected by fluorosis. Dental caries experience was measured by DMFS score (overall caries experience and untreated decay). OHRQoL was calculated as sum of 7 items out of the 14 items NHANES Oral Health Impact Profile (OHIP-14). OHRQoL score can range 6-28 (lower score indicates better oral health). Other covariates were socio-demographic characteristics, self-perceived mouth/teeth condition (1-item), and previous dental visit (time and reason). Bivariate and multivariate analyses were conducted with caries and OHRQoL as outcomes. All analyses were weighted and adjusted for the complex design of the NHANES survey, using SAS 9.3 survey procedures. RESULTS: For aim 1, dental fluorosis prevalence among persons aged 6-19 was increasing (37% vs. 57%) from 1999-2004 to 2011-2012. There was a significant increase in caries experience and a significant decrease in untreated tooth decay from 1999-2004 to 2011-2012 among persons aged 6-19. For aim 2, the crude association between the severity of fluorosis and DMFS was significantly inversely proportional except for the moderate/severe categories of fluorosis where the relationship was linear. For aim 3, the bivariate all teeth analysis showed that OHRQoL was significantly decreased with higher level of fluorosis severity (p-value=0.05). Severity of fluorosis was significantly inversely associated with DMFS score (β-coefficient=-4.8, p-value <0.0001). The lower DMFS scores explain the better perception of oral health (lower OHRQoL scores) in higher fluorosis severity groups. However, after controlling of DMFS and covariates in a multiple regression model, fluorosis severity was not significantly associated with lower OHRQoL score. CONCLUSIONS: Overall, the findings of this study suggest that the prevalence of dental fluorosis is increasing while untreated decay is decreasing among persons aged 6-19. The results demonstrated a clear inverse relationship between dental fluorosis and caries. The findings also suggest that the benefit of fluorides outweighs the esthetic impact of fluorosis among the U.S children and adolescents.