This is the first study to report the prevalence of dental caries and associated factors in Vietnam’s rural highlands, which face many difficulties compared to other regions in Vietnam. We found that the prevalence of dental caries was relatively high, especially in permanent teeth. We also found a difference in the prevalence of dental caries in primary teeth between children of the Jarai and Kinh ethnic groups. Furthermore, children with insufficient knowledge, attitudes, and practices related to dental caries were more likely to have dental caries than those who had good knowledge, attitudes, and practice. This study provides evidence related to dental caries so that policymakers can develop appropriate intervention plans for rural highland areas in Vietnam.
Dental caries is a concerning issue because it is common among children and negatively impacts a child’s quality of life. Caries is a global public health challenge and is continuously studied and documented in various countries. In 2020, the global prevalence of dental caries in primary and permanent teeth was estimated at 46.2 and 53.8 %, respectively, which was considered to be high . Since our study only included children aged 11–14 years, we report a prevalence of dental caries that varies slightly from those results. We do report findings that are consistent with other previous studies, which also indicated a high prevalence of dental caries among children [21,22,23,24,25]. The prevalence of dental caries in our study was higher than that reported by certain previous studies [21, 22, 24, 26], but lower than that reported by other studies in the same age group [23, 25]. This variation in reported prevalence of dental caries could be due to differences in economic conditions or strategies of preventive medicine in response to oral health problems in each country. In addition, differences may be due to differing sample sizes, sample selection methods, and study dates. However, the prevalence of dental caries among children was generally high in previous studies. The prevalence of dental caries tends to be lower in developed countries and higher in developing countries [20, 27], suggesting that concrete and creative strategies still need to be developed to deal with dental caries, especially in developing countries. Furthermore, as dental caries may disproportionally affect disadvantaged groups [28, 29], it is necessary to develop appropriate oral care public health policies that target marginalized socioeconomic groups.
The relatively high prevalence of dental caries that we found is consistent with previous studies conducted in Vietnam [14, 15, 17], although it is slightly lower than the prevalence reported by Do et al., who began collecting data in 1999 . However, when comparing by age group, our findings were quite similar to theirs. This is a considerable issue and suggests that, although there have been many positive socioeconomic changes in Vietnam in the 20 years between that study and this one, existing policies may not have been sufficient to improve public dental health in rural highland areas. Similarly, we found a lower prevalence of dental caries than did two other reports, although those studies focused on children in kindergarten and primary school age groups, who are at increased risk for dental caries [16, 17]. We suggest that, given the number of studies focusing on younger children, future studies should also focus on children of secondary school age.
We also found a significant relationship between dental caries and knowledge, attitudes, and practices related to dental caries. Our results are similar to previous studies that also reported that children who recognized a dental health problem were less likely to develop dental caries [30, 31]. However, like previous studies, we also found that the prevalence of good knowledge, attitude, and practices related to dental caries was low among schoolchildren [17, 32, 33]. In Vietnam, the School Oral Health Promotion Program has been implemented to improve students’ understanding of oral health since 1980. However, Thuy et al. reported concern that the program has not improved oral health behavior among schoolchildren , indicating that policymakers should provide more effective plans to enhance oral health behavior among schoolchildren. In addition, water fluoridation rates in communities and schools have remained low, something that, if improved, could reduce the prevalence of dental caries among schoolchildren. Moreover, a relationship between parental behavior and dental caries among schoolchildren has been reported , suggesting that there is also a need for oral health education programs that target parents.
Whereas some previous studies revealed differences in the prevalence of dental caries between boys and girls [14,15,16], we found no differences, as did a study in India . In addition, we observed that the prevalence of dental caries in the Jarai minority ethnic group was slightly higher than that in the Kinh majority ethnic group, although this difference was not statistically significant. In Vietnam, minority ethnic groups are considered to be vulnerable groups, so they often enjoy advantageous social benefits and government health policies, something that may have contributed to a narrowing of the disparity in disease prevalence between the Jarai and the Kinh ethnic groups. Even so, there may be differences in oral disease patterns among minority ethnic groups due to differing economic conditions within households from various groups. Therefore, we suggest that further research is needed in order to better understand inequalities in dental caries among schoolchildren so that more relevant interventions and policies are created in the future [35, 36].
In this study, we found no difference in the prevalence of dental caries in permanent teeth according to age group. This finding differs from previous studies that reported a higher prevalence of dental caries in permanent teeth in older age groups [37, 38]. This difference may be due to the age groups in our study were older than the age groups in previous studies. However, we did observe that the prevalence of dental caries in primary teeth differed according to age group, indicating that younger children had a higher risk of dental caries than did older children. This was also reported in previous studies [14, 37, 38], along with the finding that younger schoolchildren were more likely to have insufficient oral hygiene practices and improper dietary habits, and thus they were more likely to have dental caries.
We also report that the prevalence of dental caries differed according to mothers’ occupations, although we found no difference when analyzing using a logistic regression model, likely due to the fact that most children’s parents were farmers or freelancers and the study having been conducted in rural areas. There is no specific guideline for classifying occupations in Vietnam, so that task was difficult to apply in practice. In addition, because people in rural areas often have many jobs that are usually short-term, parents with very diverse jobs might all have been classified as freelancers. With such occupation demographics, it is possible that parental employment influences children’s dental health [34, 39]. Similarly, it is possible that children from families whose parents work in more stable jobs (e.g., officials or workers) are more likely to receive adequate oral health care. We suggest that more studies are needed in the future to learn more specifically the role of parental occupation in children’s dental health.
We also wish to address some of the limitations of this study. The diagnosis of dental caries based solely on dental examination without using radiography may not detect all cases of dental caries. Although experienced researchers designed the questionnaires about knowledge, attitude, and practices related to dental caries, some children might not have understood the questions, thus affecting our results. Beyond that, the chosen cutoff threshold for determining good and insufficient knowledge, attitudes, and practices may have influenced our results. Furthermore, while parental education may also relate to children’s oral health behavior, given that we interviewed the study participants at school, we did not collect information regarding parental education. It could also be a limitation related to the age examination because some teeth might not fully erupt. Finally, this study is a cross-sectional study and our results should not be interpreted to indicate causality.