The disparity in caries and sealants between migrant and native children in Shanghai: A cross-sectional study

Objective To investigate the disparity in dental caries between native and migrant children in Shanghai, China. Methods Between 2013 and 2015, a random cluster sample of native and migrant children aged 5, 9, 12 and 15 years was collected from each district in Shanghai. Oral examination was performed following the World Health Organization (WHO) method, and findings were reported as decayed-missing-filled teeth of primary dentition (dmft) and permanent dentition (DMFT). Results A total of 10 150 children were examined, and 33.6% of them were migrants. Migrant children had a higher prevalence of deciduous caries than native children (the 5-year-old age group, 67.8% vs 63.0%, P = 0.024; the 9-year-old age group, 75.9% vs 66.1%, P < 0.001), and higher dmft values were found in migrant children. But with respect to permanent teeth, no statistical differences were found between the two groups in caries prevalence or DMFT. After controlling for potential confounders by logistic regression, migrant children showed a higher risk of deciduous caries (odds ratio 1.42, 95% confidence interval 1.25-1.61, P < 0.001) but not of permanent caries. Migrant children exhibited relatively lower deciduous Restorative Care Index (RCI). However, 9- and 15-year-old migrant children had a higher permanent RCI than their native counterparts. Conclusions Dental caries prevalence in migrant children was higher in the deciduous teeth but not in the permanent teeth compared to that in their native counterparts. School-based dental public health services may contribute to reducing the disparity in dental health status between migrant and native children.