Abstract
BACKGROUND: Understanding the anatomical distribution and severity of dental caries is crucial for developing targeted preventive and therapeutic strategies in pediatric populations. While global prevalence studies offer a general overview of disease burden, few have explored caries patterns by tooth type and surface in young children. This study aimed to assess the distribution and severity of dental caries lesions in primary teeth among Costa Rican preschool children enrolled in public early childhood centers. METHODS: A cross-sectional descriptive study was conducted through a secondary analysis of data from an oral health survey involving 803 children under 81 months of age attending government-run early childhood care and nutrition centers, which serve low-income populations in Costa Rica. Calibrated dentists conducted clinical examinations using the International Caries Detection and Assessment System (ICDAS). Each tooth was evaluated individually, with the most severely affected surface recorded for analysis. Lesions were classified as noncavitated (ICDAS codes 1-2) or cavitated (codes 3-6). Descriptive statistics were performed to analyze the frequency and severity of carious lesions by tooth and surface. RESULTS: The second primary molars were the most frequently affected teeth, accounting for 15.81% (95% confidence interval (CI): 13.4-18.2) of all caries-affected surfaces, followed by the first primary molars (11.56%). The highest average severity was observed in the upper central incisors (mean ICDAS = 4.25, 95% CI: 4.10-4.40). Occlusal surfaces were the most commonly affected (18.09%), whereas buccal surfaces represented the largest proportion of total lesions (39.32%). Although distal surfaces were less frequently affected (2.38%), they exhibited the highest average severity (4.86). Noncavitated caries lesions were predominant, especially on the second molars and buccal surfaces, while proximal surfaces had a greater proportion of advanced lesions. CONCLUSIONS: Second primary molars were the most frequently affected teeth, while upper central incisors exhibited the highest caries lesion severity. Occlusal and buccal surfaces together accounted for the largest proportion of carious lesions. These findings underscore the need for preventive strategies tailored to anatomical risk patterns in preschool populations.