Abstract / Summary
Abstract Objective: To estimate the prevalence of molar–incisor hypomineralization (MIH) among primary school children in Shaanxi Province, China, and to explore associated prenatal, perinatal, and early-life factors. Method: A population-based cross-sectional study was conducted using a stratified cluster random sampling design. Children aged 7-10 years were recruited from three cities (Yan’an, Xianyang, and Hanzhong). Standardized oral examinations were performed by calibrated examiners according to the European Academy of Paediatric Dentistry (EAPD) criteria. Structured questionnaires were administered to caregivers to collect information on prenatal, perinatal, and early childhood exposures. Associations were evaluated using chi-square tests and multivariate logistic regression, with odds ratios (ORs) and 95% confidence intervals (CIs) reported. Results: A total of 2,694 children were included. The overall prevalence of MIH was 22.16%, with no significant sex difference. Significant regional variation was observed, with higher prevalence in Yan’an and Xianyang compared with Hanzhong. In multivariate analysis, amoxicillin exposure (OR=18.88, 95%CI:14.10-25.28) and maternal diarrhea during the third trimester (OR=9.72, 95%CI:4.15-22.74) were strongly associated with MIH. In contrast, preterm birth (OR=0.60, 95%CI: 0.45–0.79) and low birth weight (OR=0.35, 95%CI: 0.23-0.54) showed inverse associations after adjustment. Conclusion: MIH is highly prevalent among schoolchildren in Shaanxi Province and shows significant geographic variation. Several prenatal and early-life factors were associated with MIH; however, causal relationships remain uncertain. These findings provide important epidemiological evidence to support early identification of high-risk groups and inform future longitudinal research.