In this background paper, sociodemographic variables, including age, race, family income, sex, parental education, and geographic location, have been used to characterize the dental status of US children and their access to dental services. Because tooth decay, or dental caries, remains the preeminent oral disease of childhood and national data is available on dental office visits, tooth decay has been used as the primary marker for children's oral health, and visits to the dentist is the marker for care. In general, children from low-income families experience the greatest amount of oral disease, the most extensive disease, and the most frequent use of dental services for pain relief. Yet these children have the fewest overall dental visits. Paradoxically, children in poverty-those living in households with annual gross incomes under $16 500 for a family of 4-or near poverty-those in family households with incomes between $16 500 and $33 000-also have the highest rates of dental insurance coverage, primarily through Medicaid and SCHIP. For those most affected, dental disease is consequential for their growth, function, behavior, and comfort. The twin disparities of poor oral health and lack of dental care are most evident among low-income preschool children, who are twice as likely to have cavities as are higher income children. Medicaid-eligible children who have cavities have twice the numbers of decayed teeth and twice the number of visits for pain relief but fewer total dental visits, compared to children coming from families with higher incomes. Fewer preventive visits for services such as sealants increase the burden of disease in low-income children. These disparities continue into adolescence and young adulthood, but to a lesser degree. Disparities in oral health status and access to dental care are also evident when comparing black, Hispanic, and Native American children to white children and when comparing children of parents with low educational attainment to children of parents with higher educational attainment. The fastest growing populations of children are those that currently have the highest disease rates and the lowest amount of dental care. If the strong correlation between these subpopulations and dental diseases continues, caries rates are likely to rebound after longstanding declines, and the stress on publicly financed dental care will likely increase.