ABSTRACT. Objective. To determine the effects of early preventive dental visits on subsequent utilization and costs of dental services among preschool-aged children.Design. This investigation studied North Carolina children who were enrolled continuously in Medicaid from birth for a 5-year period. Our research design was a longitudinal cohort study that relied on 4 large administrative datasets, including North Carolina composite birth records from 1992, Medicaid enrollment and claims files from 1992 to 1997, and the Area Resource File. Our outcome measures included type of use and dentally related costs.Results. Of the 53 591 Medicaid-enrolled children born in 1992, 9204 were continuously enrolled for 5 years and met our inclusion criteria. Twenty-three children had their first preventive dental visit before 1 year of age, 249 between 1 and 2 years, 465 between 2 and 3 years, 915 between 3 and 4 years, and 823 between 4 and 5 years. Children who had their first preventive dental visit by age 1 were more likely to have subsequent preventive visits but were not more likely to have subsequent restorative or emergency visits. Those who had their first preventive visit at age 2 or 3 were more likely to have subsequent preventive, restorative, and emergency visits. The age at the first preventive dental visit had a significant positive effect on dentally related expenditures, with the average dentally related costs being less for children who received earlier preventive care. The average dentally related costs per child according to age at the first preventive visit were as follows: before age 1, $262; age 1 to 2, $339; age 2 to 3, $449; age 3 to 4, $492; age 4 to 5, $546.Conclusions. Our results should be interpreted cautiously, because of the potential for selection bias; however, we concluded that preschool-aged, Medicaid-enrolled children who had an early preventive dental visit were more likely to use subsequent preventive services and experience lower dentally related costs. In addition, children from racial minority groups had significantly more difficulty in finding access to dental care, as did those in counties with fewer dentists per population. Pediatrics 2004;114:e418-e423. URL: www.pediatrics.org/ cgi/doi/10.1542/peds.2003-0469-F; early childhood caries, preventive dental visit, cost, first dental visit, Medicaid dental use.ABBREVIATIONS. ECC, early childhood caries; NC, North Carolina; DPCR, number of dentists per 10 000 population according to county of residence. E arly childhood caries (ECC) is defined as dental decay among children Յ5 years of age. 1 It is estimated that 2% of infants 12 to 23 months of age in the United States have at least 1 tooth with questionable decay, whereas 19% of children 24 to 60 months of age meet the criteria for ECC. 2 ECC is much more prevalent among children from low-income families; for example, among children 3 to 5 years of age in Head Start, the prevalence of ECC has been reported to be as high as 90%. 3,4 Untreated caries is concentrated disproportionately among...