Very little is known from prior literature about the relationship between very low birth weight (VLBW), bronchopulmonary dysplasia (BPD) and dental caries in the permanent dentition, due to the fact that only recently are increasing numbers surviving to adolescence because of improved neonatal technology. Both dental caries and VLBW disproportionately affect the poor and minority groups. It is known that VLBW children have a high prevalence of enamel defects in the primary dentition, which in turn can lead to increased susceptibility of the dental enamel to dental caries. The primary objective of this study is to assess the relationship between BPD, VLBW and caries in the permanent dentition of 14-year-old adolescents. Secondarily, we propose to explore the possible mechanisms underlying this relationship by looking at enamel defects, oral health behavior, and synergistic effects of these two factors. Approximately 302 children (110 VLBW with BPD, 80 VLBW without BPD, 112 term healthy) will be studied for dental problems in conjunction with an ongoing developmental study (primary study). The proposed study will collect data on outcome (dental caries), mediating (enamel defects, oral health behavior of child, oral hygiene status) and independent (oral health knowledge, parent's dental behavior) variables. The primary study will provide data on other independent variables such as medical, sociodemographic, parent stressors and cognitive variables. Data analysis includes ANOVA, GLIM procedures for the primary aim, and multivariate regression models for testing mediation effects. Our proposed study is expected to provide much needed data on the extent of oral health problems in the permanent dentition of VLBW adolescents, and to support the further development of an R01 application. The clinical implications include early diagnosis and treatment to prevent further susceptibility to tooth loss and other dental diseases. It is also of public health interest since interventions to target attitudes and oral health practices can be implemented in programs for special health needs children, and there by be useful for improving both oral and general health. ? ? ?