Disparities in the geospatial distribution of dentists in the United States in 2017

Objectives Advanced dental and oral health conditions disproportionately affect racial and ethnic minority patients and patients of low socioeconomic status. The impact that the geographic distribution of dentists has on these disparities is largely unknown. The aims of this study were to map the geographic distribution of dentists within the United States at the county level and to determine whether this distribution explains a component of the observed health disparities. Methods The number and primary practice locations of all dentists in the United States in 2017 were extracted from the Health Resources and Services Administration's Area Health Resources Files. These data were combined with US census data to determine the density of dentists per capita at the county level, which was analyzed for association with population-level demographic characteristics using bivariable and multivariable linear regression. Results The median density of dentists by county in the United States is 33.7 dentists per 100,000 people (standard deviation, 24.4). Multivariable analysis showed that the density of dentists was positively associated with the percentage of residents with a college education, where the highest quartile of counties had 28.1 more dentists per 100,000 than the lowest (95% confidence interval [CI], 25.6, 30.6), and was negatively associated with the percentage of residents who were uninsured, where the highest quartile of counties had 12.5 fewer dentists per 100,000 than the lowest (95% CI, −15.0, −10.0), but the density of dentists was not associated with median household income. Furthermore, the density of dentists was positively associated with a greater non-White population composition, where the highest quartile of counties had 7.7 more dentists per 100,000 than the lowest (95% CI, 5.3, 10.0). Finally, the density of dentists was associated with some quantiles of urbanicity, where the most rural quantile of counties had 12.4 fewer dentists per 100,000 than the most urban (95% CI, −15.25, −9.56). Conclusions Dentists are unequally distributed within the United States. Controlling for population characteristics, counties with greater non-White population composition have more dentists per capita. Geographic access was not shown to adequately account for observed oral health disparities, indicating that there may be more important barriers to dental care for minority patients.