Oral health and associated factors among children aged 6–12 years in a high-altitude region of China

Relevance. China’s high-altitude regions are characterized by extreme climatic and geographic factors, including hypoxia, ultraviolet radiation, an arid climate, and low levels of trace elements in water. Together with traditional dietary habits, these factors may adversely affect children’s oral health. Comprehensive epidemiological data from these regions remain limited.

Materials and methods. This cross-sectional study included 128 children aged 6–12 years in Wuqia County, a high-altitude area of Xinjiang located at an elevation of >2,500 m. The prevalence of dental caries (DMFT/dmft index), gingivitis (Löe–Silness — Gingival Index [GI]) and malocclusion (Angle classification) was assessed. Parents completed a questionnaire. Data were analyzed using the χ² test, ANOVA, and logistic regression analysis.

Results. A high prevalence of caries in the primary dentition (91.5%), gingivitis (29.5%), and malocclusion (68.7%) was found. The main risk factors were frequent carbohydrate intake (OR = 2.85), irregular toothbrushing (OR = 2.41–2.93), low parental educational attainment (OR = 1.98), visible dental plaque or calculus (OR = 4.12), and deleterious oral habits (OR = 3.28).

Conclusion. Children living in the high-altitude regions of Xinjiang have an extremely high burden of oral disease, indicating the need to develop region-specific preventive programs that take behavioral, social, and environmental risk factors into account.

1. Peres MA, Macpherson LMD, Weyant RJ, Daly B, Venturelli R, Mathur MR, et al. Oral diseases: a global public health challenge. Lancet. 2019;394(10194):249-260. https://doi.org/10.1016/S0140-6736(19)31146-8

2. Kassebaum NJ, Bernabé E, Dahiya M, Bhandari B, Murray CJ, Marcenes W. Global burden of untreated caries: a systematic review and metaregression. Journal of dental research. 2015;94(5):650–658. https://doi.org/10.1177/0022034515573272

3. Omara M, Stamm T, Bekes K. Four-dimensional oral health-related quality of life impact in children: A systematic review. J Oral Rehabil. 2021;48(3):293–304. https://doi.org/10.1111/joor.13066

4. WHO. Oral health surveys: basic methods. 5th ed. Geneva: World Health Organization; 2013. Available from: https://www.who.int/publications/i/item/9789241548649

5. Tinanoff N, Baez RJ, Diaz Guillory C, Donly KJ, Feldens CA, McGrath C, , et al. Early childhood caries epidemiology, aetiology, risk assessment, societal burden, management, education, and policy: Global perspective. Int J Paediatr Dent. 2019;29(3):238–248. https://doi.org/10.1111/ipd.12484

6. Smolina A.A., Kunin V.V., Vecherkina Zh.V., Chirkova N.V., Koretskaya I.V. Assesment of organizational measures to reduce morbidity of children with caries. Journal of new medical technologies. 2017;24 (2):172-177 (In Russ.). Available from: https://www.elibrary.ru/item.asp?id=29853674

7. Lu HX, Tao DY, Lo ECM, Li R, Wang X, Tai BJ, et al. The 4th National Oral Health Survey in the Mainland of China: Background and Methodology. Chin J Dent Res. 2018;21(3):161–165. https://doi.org/10.3290/j.cjdr.a41079

8. Zhen YE, Kai-xian GAO, Xiao-qing YIN. Prevalence of Dental Caries and Related Risk Factors in Primary School Students [J]. Journal of Oral Science Research. 2018;34(1):32-34. https://doi.org/10.13701/j.cnki.kqyxyj.2018.01.008

9. Wu SC, Ma XX, Zhang ZY, Lo ECM, Wang X, Wang B, et al. Ethnic Disparities in Dental Caries among Adolescents in China. J Dent Res. 2021;100(5):496–506. https://doi.org/10.1177/0022034520976541

10. Stepanova A.V., Godina E.Z. Growth and development of children at high-altitudes: conditions: interpopulation comparison. Part I. Morphofunctional characteristics of girls. Lomonosov journal of anthropology. 2015;(4):14-33 (In Russ.). Available from: https://www.elibrary.ru/item.asp?id=25797714

11. Muratov Zh.K The influence of high-altitude factors on the human body. Novoe slovo v nauke: perspektivy razvitiya. 2016;(1-1):129-133 (In Russ.). Available from: https://www.elibrary.ru/item.asp?id=25511152

12. Jin L, Zhenjie L, Qing H, Alim A. Variation in Surface Solar Radiation and the Influencing Factors in Xinjiang, Northwestern China. Advances in Meteorology. 2022:1999997. https://doi.org/10.1155/2022/1999997

13. Zhang Y, Long A, Lv T, Deng X, Wang Y, Pang N, et al. Trends, Cycles, and Spatial Distribution of the Precipitation, Potential Evapotranspiration and Aridity Index in Xinjiang, China. Water. 2023;15(1):62. https://doi.org/10.3390/w15010062

14. Meng X, Wang H, Chen J, Yang M, Pan Z. High-resolution simulation and validation of soil moisture in the arid region of Northwest China. Sci Rep. 2019;9(1):17227. https://doi.org/10.1038/s41598-019-52923-x

15. Liu J, Yao H, Zhang L, et al. Dietary patterns among adult Uyghur residents in Xinjiang. Chinese Journal of Public Health. 2016,32(9):1212-1218 (In Chinese). https://doi.org/10.11847/zgggws2016-32-09-21

16. Carvalho Silva C, Gavinha S, Vilela S, Rodrigues R, Manso MC, Severo M, et al. Dietary Patterns and Oral Health Behaviours Associated with Caries Development from 4 to 7 Years of Age. Life (Basel). 2021;11(7):609. https://doi.org/10.3390/life11070609

17. Riziwaguli A, Asiya Y, Liu Y, Yang R, Zou J. Caries prevalence of the first permanent molar among 7-9 years old Uygur children in Urumqi, Xinjiang Autonomous Region. Shanghai Kou Qiang Yi Xue. 2013;22(5):559-61 (In Chinese). Available from: https://pubmed.ncbi.nlm.nih.gov/24233210/

18. Tychinina A.P. Adaptation of a child's body to various climate-geographical regions (literature review). Modern Issues of Biomedicine. 2025;9(3):116–122 (In Russ.). https://doi.org/10.24412/2588-0500-2025_09_03_16

19. Zyryanov В.N., Antonov O.V. V. Immunity and Dental Caries in Native and Immigrant School-Age Children Living in the Far North. Vestnik SurGU. Meditsina. 2022;(2):28-34 (In Russ.). https://doi.org/10.34822/2304-9448-2022-2-28-34

20. Lianova D.K., Avdol'yan S.A., Slonova V.M., Gontarev A.G., Daurova F.Yu. Studying epidemiology of stomatologic diseases of the children's population of Republic Northern-Ossetia Alania. RUDN Journal of Medicine. 2008;(2):48-51 (In Russ.) Available from: https://www.elibrary.ru/item.asp?id=10429336

21. National Center for Disease Control and Prevention. Sanitary standards for drinking water quality. GB 5749-2022. 2022. https://www.ndcpa.gov.cn/jbkzzx/c100201/common/content/content_1665979083259711488.html.

22. World Health Organization. Guidelines for Drinking Water Quality: Fourth Edition, Including the First and Second Addenda. Geneva, 2022.

23. Kezhou Environmental Safety Administration, Wucheng Branch. Report on the Monitoring of Atmospheric Air Quality in Wucheng County for the First Quarter of 2025. April 9, 2025. https://www.xjwqx.gov.cn/xjwqx/c102761/202504/8395c344f5b24848b32bfb2837c15363.shtml.

24. Environmental Safety Administration of Wucheng County People's Government. (2025). Surface Water Information of the First Quarter of 2025 [Data Report]. https://www.xjwqx.gov.cn/xjwqx/c102760/202605/3daa3ebcdfaa472d90af8e2b13fbdb33.shtml

25. Li H, Liu X, Xu J, Li S, Li X. The Prevalence of Dental Carious Lesions and Associated Risk Factors in Chinese Children Aged 7-9 Years. Oral Health Prev Dent. 2024;22:349–356. https://doi.org/10.3290/j.ohpd.b5628793

26. Xu J, Li X, Liu X, Li S, Lu Y. Prevalence and Influencing Factors of Mixed Dentition Malocclusion in Children Aged 6-12 Years in Jinzhou, China. Oral Health Prev Dent. 2023;21:163–170. https://doi.org/10.3290/j.ohpd.b4100913

27. Liu X, Xu J, Li S, Wang X, Liu J, Li X. The prevalence of gingivitis and related risk factors in schoolchildren aged 6-12 years old. BMC Oral Health. 2022;22(1):623. https://doi.org/10.1186/s12903-022-02670-9

28. Lin M, Xie C, Yang H, Wu C, Ren A. Prevalence of malocclusion in Chinese schoolchildren from 1991 to 2018: A systematic review and meta-analysis. Int J Paediatr Dent. 2020;30(2):144–155. https://doi.org/10.1111/ipd.12591