Abstract: PURPOSE: To assess the oral health behaviors and risk factors of 5-year-old children in Yuecheng District, Shaoxing City, Zhejiang Province, in order to identify major oral health issues and propose measures for improvements. METHODS: This retrospective study was conducted from September to October 2023, involving 5-year-old children from 22 kindergartens in Yuecheng District. The survey was administered after obtaining informed consent from the children's parents, who completed a questionnaire regarding their children's oral health behaviors and awareness, as well as the oral health status of the children. RESULTS: A total of 2 108 online electronic questionnaires were collected, with 1 965(1 063 male and 902 female children) confirmed as complete and valid, achieving an effective response rate of 93.2%. After oral examination of 1 641 children, the form data were complete, and 1 635 valid data were obtained (826 male and 809 female children), with a completion rate of 99.6%. The average number of decayed, missing, and filled primary teeth (dmft) for 5-year-old children were 3.95, 0.01 and 0.66, respectively. In Yuecheng District, the averages for decayed and filled primary teeth were significantly higher than the national average in 2018. The survey results indicated that the frequency of sweet food consumption of children in Yuecheng District was significantly lower than the national average, while the habits of brushing teeth, parental assistance in brushing and the use of fluoride toothpaste were significantly higher than the national average. The positive attitude and awareness rate of parents of 5-year-old children on oral health in Yuecheng District were significantly higher than the national average(P<0.05). Univariate analysis of the factors influencing oral health in 5-year-old children showed that the presence of dental caries was significantly associated with dietary habits, oral hygiene behaviors, parental attitudes toward oral health and parental knowledge of oral health (P<0.05). The independent risk factors for dental caries in 5-year-old children in Yuecheng District were eating sweets and candies more than twice a day(OR=1.065), drinking sweetened beverages more than twice a day(OR=1.189) and drinking sweetened milk or formula more than twice a day (OR=1.234, P<0.05). The independent protective factors for dental caries in 5-year-old children in the same region included brushing teeth daily(OR=0.863), brushing teeth twice or more per day(OR=0.884), using fluoride toothpaste(OR=0.876), parental assistance with brushing(OR=0.814), regular dental check-ups(OR=0.834), belief that bacteria can cause caries(OR=0.862), awareness that sugar can lead to caries(OR=0.799), the need for treatment of caries in deciduous teeth(OR=0.860) and the protective effect of fluoride on teeth(OR=0.823, P<0.05). CONCLUSIONS: The higher DMFT and filling rates of 5-year-old children in Yuecheng District of Shaoxing City indicate better oral hygiene conditions. The positive influence of parents' proactive attitudes and higher levels of oral health knowledge has positively impacted children's oral health. It is necessary to strengthen the control of children's sweet food intake and improve parents' oral health awareness to further reduce the occurrence of children's oral health problems.

Key words: Child oral health, Primary tooth decay, Hygiene behavior, Investigation and analysis