Dental caries status of Bulang preschool children in Southwest China

Background: Bulang is one of the 55 ethnic minorities in China with a population of around 120,000. They live mainly in Yunnan, which is a less-developed province in southwestern China. Many Bulang people live in remote villages and have little access to dental care. They like hot and sour food and chew betel nut. This study examines the caries status of 5-year-old Bulang children and factors that influence their caries status. Methods: A sample of 5-year-old Bulang children in Yunnan was selected using a multi-stage cluster sampling method. One trained dentist examined the children using dental mirrors with intra-oral LED light and CPI probes. Caries experience was measured according to the dmft index. Oral hygiene status was recorded according to the visible plaque index (VPI). A parental questionnaire was used to study the children's oral health-related behaviours. Results: A total of 775 children were invited and 723 joined the survey. The caries prevalence was 85%, and 38% of them had caries involved in pulp. The mean dmft and dt score were 5.8 +/- 4.9 and 5.6 +/- 4.8, respectively. Visible plaque was found on 636 children (88%). Multi-factor ANCOVA analysis found that higher dmft scores were found among the children who snacked on sweets daily, had visited a dentist within the last year and had higher VPI scores. Conclusions: The caries prevalence and experience among 5-year-old Bulang children in Yunnan was high, and most of the caries were left untreated. The caries experience was associated with snacking habits, dental visit habits and oral hygiene.