Risk factors associated with early childhood caries among Wenzhou preschool children in China: a prospective, observational cohort study.

OBJECTIVES: Early childhood caries (ECC) is a serious health public problem that affects a large proportion of children in China. This study aimed to assess risk factors for the incidence of ECC among Wenzhou (China) preschoolers. DESIGN: Prospective, observational cohort study. SETTING: Kindergartens (n=6) in Wenzhou, China. PARTICIPANTS: 606 children who were 3-4 years of age and newly arrived in the kindergartens in September 2011. METHODS: This was a longitudinal observational study with a 2-year follow-up of preschoolers of 3-4 years of age in Wenzhou (Southeast China). Oral health data were collected annually after the baseline survey. The risk factors associated with visible caries and increment of decayed, missing and filled teeth (dmft) were analysed through univariable and multivariable regression using generalised estimating equations. RESULTS: The prevalence of ECC was increasing during the follow-up period (59.8% at enrolment, 71.8% at first year, and 76.4% at second year). Older age (b=0.07; 95% CI: 0.05 to 0.09; p<0.001), caregivers (relatives or nannies) (b=-1.20; 95% CI: -2.23 to -0.16; p=0.023), lower annual family income ( yen10 000- yen20 000: b=2.04; 95% CI: 1.04 to 3.04; p<0.001; < yen10 000: b=1.78; 95% CI: 0.65 to 2.92; p=0.002) and more frequent consumption of sugary snacks/drinks at night (sometimes: b=0.88; 95% CI: 0.20 to 1.56; p=0.011; always: b=1.19; 95% CI: 0.13 to 2.25; p=0.028) were independently associated with the increments of dmft. Older age (OR=1.04, 95% CI: 1.03 to 1.05, p<0.001) and more frequent consumption of sweet snacks (OR=1.86, 95% CI: 1.06 to 3.27; p=0.030) were independently associated with a higher risk of visible caries. CONCLUSIONS: The occurrence and severity of ECC were associated with older age, caregivers (relatives or nannies), lower annual family income and more frequent consumption of sweet snacks. It is imperative to strengthen oral health education for parents and limit sugary foods/snacks.