Developmental defects of enamel in primary teeth: highly prevalent, unevenly distributed in the oral cavity and not associated with birth weight.

Aim: Estimate the prevalence of developmental defects of enamel (DDE) in the primary dentition, describe the distribution among tooth groups and investigate the association with birth weight.

Methods: A cross-sectional study was conducted with a sample of 827 children aged 2-5 years representative of the city of Canela in southern Brazil. Demographic characteristics (gender and age) and birth weight were collected from vaccination cards. The diagnosis of DDE was performed by six trained examiners following the criteria of the Federation Dentaire International. DDE were described both jointly and separately as opacity and hypoplasia. Statistical analysis involved the Chi square test, Mann-Whitney test and Poisson regression with robust variance.

Results: The prevalence of DDE was 55.1% (95% CI 51.6-58.5%), with a mean of 3.0 ± 2.2 teeth affected. Opacity was the more frequent defect (50.4%), followed by hypoplasia (15.5%). Distribution of the defects was uneven, with opacity predominant on second molars and hypoplasia predominant on canines and second molars. Children with a low birth weight did not have a greater probability of opacity (PR: 1.13; 95% CI 0.91-1.41), hypoplasia (PR: 1.33; 95% CI 0.80-2.22) or DDE (PR: 1.11; 95% CI 0.91-1.37).

Conclusion: The prevalence of DDE was high, predominant on second molars and not associated with birth weight. These findings indicate directions for future examination/diagnosis protocols and specific orientations.