Dental Caries Status among Yi Preschool Children in Yunnan Province, China: A Cross-Sectional Study

The Yi ethnic group is the sixth largest minority in China. The aim of this study was to investigate dental caries status among Yi preschool children in the Yunnan province, China.

This cross-sectional study invited 5-year-old Yi children using multistage cluster sampling. Two trained and calibrated dentists examined the children in kindergartens. The children's dental caries experience was assessed using the decayed, missing, and filled teeth (dmft) index. Visual plaque on an indexed tooth of each six sextants was recorded and the oral hygiene status was assessed using the Visible Plaque Index. Parents completed questionnaires that surveyed their educational attainment. The questionnaires also collected information about the children's demographics, snacking habits, oral-health-related behaviors and dental visit experiences. The associations between caries experiences and potential factors were analyzed using zero-inflated negative binomial regression.

All 452 invited children (249 boys, 55%) participated in this study with a response rate of 100%. Dental caries prevalence rate was 83%. The mean dmft score and decayed teeth score were 5.2 ± 4.4 and 5.1 ± 4.4, respectively. Almost half of the children (n = 211, 47%) had visible plaque on four or more of the six sextants. Most (n = 366, 81%) of the children had not visited a dentist in the prior 12 months. Regression analysis found the children's caries experience was associated with their dental visit experience.

The great majority of the Yi preschool children experienced dental caries and almost all of the cavities were not restored. Their oral hygiene was poor and visible plaque was commonly found on their teeth.