During the Japan International Cooperation Agency (JICA) partnership program in Mongolia, six times between October 2017 and October 2019, education for caries prevention, a questionnaire of daily oral health behavior, and an oral examination for parents and children aged 0-5 years old were done. The target parent population were middle socio-economic class families. In total, there were 2223 participants. The caries prevalence measured in October 2017, January, April, and October 2018, and April and October 2019, was 78.0% (95% CI: 74.2-81.4); 79.4% (73.7-84.4); 80.8% (76.2-84.9); 76.4% (70.1-82.0); 89.3% (85.3-92.6); and 82.6% (79.3-85.6), respectively. Compared to October 2017, in October 2019, the deft of three years old was significantly decreased (p < 0.01) and that of four years old was also decreased (p = 0.085). For the prevention of early childhood caries (ECC), daily oral health behaviors are important. In 2019, compared with the percentage of 0-5 years old in 2017, the frequency of tooth cleaning per day, parents cleaning after children, and parents watching during children's tooth cleaning were significantly increased (p < 0.01). Unfortunately, the frequency of sugary-snack intake per day showed an increased tendency (p < 0.05). The baby teeth decayed, extracted and filled (deft) index at three and/or four years old in October 2019 was correlated with the childrens' background characteristics, such as parent educational attainment, frequency of sweets intake, frequency of daily tooth cleaning, and parental cleaning of children's teeth. The effects of the JICA program were recognized.
Keywords: Mongolia; caries prevalence; deft; early childhood caries (ECC).