Racial and ethnic minorities comprise a significant portion of the population in the United States. According to the Centers for Disease Control and Prevention, minorities are defined as Hispanic or Latinos, black or African Americans, Asian Americans, American Indians and Alaska Natives, and Native Hawaiians or Pacific Islanders. Based on 2011 US Census Bureau data, 36.6% of the population is of minority descent, including 16.7% Hispanic or Latino, 13.1% black or African American, 5% Asian, 1.2% American Indian or Alaska Native, and less than 1% Native Hawaiian or Pacific Islander. As the proportion of minorities in the United States continues to grow, it is critical to understand and address racial and ethnic oral health disparities, which is an important step toward achieving health equity and social justice.

Minority children experience oral health disparities. Based on data from the 2007 National Survey of Children’s Health, 15% of non-Hispanic white children did not have an annual preventive dental visit, and 24% of Hispanic children and 18% of black children did not have a visit. Based on the same data, 8.8% of white children were rated by their parent as having fair or poor oral health, but 20.4% of Hispanic children and 10% of black children had fair or poor oral health. In another study focusing on privately insured children in Milwaukee, Wisconsin, black and Hispanic children received significantly fewer preventive dental procedures than did white children. After adjusting for household income, black children were less likely than whites to receive most dental procedures. These findings parallel studies focusing on Medicaid populations. In Iowa, African American children in Medicaid were significantly less likely to have a dental checkup than were white children.

Minorities are also more likely to have malocclusions and orthodontic treatment needs. Authors of a study in 1998 examined Class II and Class III malocclusions using National Health and Nutrition Examination Survey III data for 7000 children. Class II malocclusion was defined as an overjet greater than 2 mm. Whites, blacks, and Mexican Americans had varying prevalence values of Class II malocclusion (57.6%, 64.4%, and 66.4%, respectively). Class III malocclusion was defined as an overjet of 0 mm or less. The prevalences of Class III malocclusion among whites, blacks, and Mexican Americans were 4.9%, 8.1%, and 8.3%, respectively. These data indicate that Class II and Class III malocclusions are more prevalent in blacks and Mexican Americans. The Index of Orthodontic Treatment Need was used to evaluate need, and minorities were more likely to have orthodontic treatment needs.

Despite data indicating greater orthodontic treatment needs for minorities, there are relatively few studies on minority orthodontic service use. Over 30% of white teenagers reported receiving orthodontic treatment—3 times the rate for Mexican American and 4 times the rate for black teenagers. In another study based on Medical Expenditure Panel Survey data, whites accounted for 59.9% of the population yet disproportionately accounted for 77.1% of those who received orthodontic treatment. After adjusting for income, blacks and Hispanics were less likely than whites to receive orthodontic treatment. Using survey data from over 2800 US high school sophomores in Ohio, the authors of a 2004 study reported that orthodontic treatment figures for whites, Mexican Americans, and African Americans were 31%, 11%, and 8%, respectively. Orthodontic use figures were over 50% in schools in suburban, affluent areas and were less than 10% in inner city high schools, which consist disproportionately of lower-income, minority students.

The federal Early and Periodic Screening, Diagnosis, and Treatment program mandates orthodontic care to correct a handicapping malocclusion for all Medicaid-enrollees through age 21 years. Based on previous findings, it is unlikely that the requirements of the Early and Periodic Screening, Diagnosis, and Treatment program are being met by state Medicaid programs for minorities, but studies to date have not examined orthodontic care use for minorities in Medicaid. To address this knowledge gap, we hypothesized that among Medicaid-enrolled children in Washington, nonwhites would be less likely to use orthodontic services than whites. We also hypothesized that factors such as ethnicity would modify the relationship between race and orthodontic use. This study is the first step in assessing the extent to which there are racial disparities in orthodontic care in Medicaid programs.