The prevalence and associated factors of early childhood caries in 3- to 5-year-old children in Shaanxi Province, China: a cross-sectional study

Objective – To determine the prevalence of early childhood caries (ECC), identify high-risk tooth sites, and analyze region-specific and early-life risk factors among 3- to 5-year-old children in Shaanxi Province, China. Methods – A cross-sectional study was conducted using stratified cluster random sampling to select 571 children from northern, central, and southern Shaanxi. Clinical oral examinations were performed following World Health Organization (WHO) criteria. Primary caregivers completed questionnaires regarding sociodemographic characteristics, birth outcomes, feeding practices, and dietary behaviors. Logistic regression analysis was employed to identify factors associated with ECC prevalence. Results – The overall ECC prevalence was 66.9%, with significant regional disparities (Northern: 85.6% vs. Central: 52.7%, P < 0.001). Caries rates increased from age 3 (54.1%) to age 5 (77.7%). The most severely affected tooth positions were the mandibular second primary molars (teeth 75, 85). High-risk surfaces included the mesial surfaces of maxillary central incisors and the occlusal surfaces of mandibular second molars. Multivariable analysis identified older age, lower BMI, and frequent sweet consumption as key risk factors. Additionally, mixed feeding, preterm birth, and low birth weight were significantly associated with caries in specific high-risk tooth positions. Conclusion – ECC prevalence in Shaanxi Province is high, characterized by distinct regional variations and specific patterns of tooth susceptibility. Preventive strategies should address perinatal factors and dietary behaviors, with targeted interventions for high-risk mandibular molars and maxillary incisors initiated in early childhood.