Association of Income Inequality With Orthodontic Use

Abstract

Background: Income inequality has also been associated with worse oral health outcomes and reduced dental utilization. It is unknown whether income inequality may motivate individuals to seek orthodontic treatment. Methods: This was a logistic mixed-effects model of deidentified claims from a private insurer in the United States with members having at least one orthodontic visit in the calendar year as the dependent variable. Total number of dental visits, age, and gender were individual-level covariates. Median household income, GINI coefficient, female population proportion, number of practicing dentists and orthodontists, population size, and population density were ZIP code- level covariates. Results: 1,860,709 individuals had at least one orthodontic claim. Adjusting for population demographics, Gini index was significantly positively associated with orthodontic utilization for children but not for adults (OR 1.69 for children, p<0.0001). Female gender was the strongest predictor of orthodontic utilization for adults and was also a significant predictor of utilization for children (OR 1.50 and 1.45, respectively, p<0.0001). Conclusions: Gini index is associated with orthodontic utilization in children in a privately insured population. Individual characteristics are more predictive of orthodontic utilization among privately insured adults.