Mapping Evidence on Early Childhood Caries Prevalence: Complexity of Worldwide Data Reporting

INTRODUCTION

Early childhood caries (ECC) is defined as the presence of one or more decayed (non-cavitated or cavitated lesions), missing or filled (due to caries) surfaces in any primary tooth of a child under 6 years of age.¹ Primary teeth maintain the space for the permanent teeth and are essential to a child’s well-being. Early childhood caries leads to a higher risk of new carious lesions,² acute and chronic pain,³ hospitalizations and emergency room visits,⁴ delays of growth and development,^5,6 and diminished quality of life of young children and their families.^7,8 Early childhood caries is preventable but currently affects %3E;600 million children worldwide and remains mostly untreated.⁹ Unquestionably, ECC’s high prevalence is a worldwide burden to society, major health concerns, and health economics issues.

In the current global environment of escalating healthcare costs and resource constraints, ECC’s prevalence is critical for countries to understand the necessary resources to prevent and provide services to reduce children’s caries burden. At the turn of the 21st century, surprisingly, ECC epidemiology is not fully defined. In a brief overview of searching the PubMed engine using the terms “dental caries” and “children,” nearly 11,000 studies are reported from different countries; however, understanding the evidence from international prevalence studies is challenging. In our literature search, only one study was found to address the global prevalence estimates for ECC. This study’s data are reported by mean values with ECC prevalence for children younger than 36 months at 23.8% and children between 36 and 71 months at 57.3%.¹⁰

The methodological variations in worldwide prevalence studies also impart barriers to a global hinder understanding of the disease. Very often, these studies: (1) have unclear study design; (2) inconsistent definition of “early childhood caries”; (3) lack reporting criteria for carious lesion identification; and (4) lack of prevalence reporting by a specific age. An analysis of ECC prevalence reported in median values for specific ages from various countries may better inform our understanding of the ECC global burden.

Hence, this mapping review aims to synthesize global dental caries prevalence data in children under 6 years of age from studies that report data by specific ages. These findings may suggest approaches to standardize methods for reporting ECC prevalence studies and assist national and global agendas addressing the worldwide ECC burden.

MATERIALS AND METHODS

Initially, an electronic literature search was performed on studies between January 1999 and December 2014 with a primary search term “early childhood caries” using Embase, PubMed, MEDLINE, Science Direct databases, Google Scholar, and World Health Organization (WHO) library databases and gray literature. Another review was performed from January 2014 through January 2019. A total of 915 studies of ECC prevalence studies were retrieved from these two searches. Two reviewers screened titles and abstracts for relevance and obtained full-text articles of publications.

Because of the methodological focus of this review, studies were excluded if: (1) they were not a controlled trial, cohort, case-controlled or cross-sectional study; (2) the sample size <100 children; (3) the diagnostic criteria used for assessing dental caries in the primary dentition was not clearly stated; (4) the country where the children were assessed was not clear; and, (5) the study did not list caries prevalence by age, i.e., 1 year old (12–23 months), 2 years old (24–35 months), 3 years old (36–47 months), 4 years old (48–59 months), and 5 years old (60–71 months). Flowchart 1 illustrates the search process for the study.

From the initially identified 915 studies, 59 withstood the exclusion criteria and were abstracted to include: (1) the number of children per age, (2) country, (3) study type, (4) caries criteria, and (5) prevalence by age. We also calculated each country’s ECC prevalence range and median values by age. Median values were calculated to observe data distribution not affected by outliers when skewed data are present.¹¹ Data also were categorized by the 2014 United Nations classification of developed and developing countries based on their economic status.¹² Data compilation, analysis, and graphing were accomplished using Microsoft Excel for Mac, Version 16.14.1, 2018, and Tableau 2020.3.

RESULTS

The 59 studies worldwide estimated overall ECC prevalence are shown in Table 1 and Figure 1. The studies were predominantly conducted in developing countries (38/59). On a country-by-country basis, the United States of America, India, and Brazil have contributed eight studies each. Regarding global contribution, 18 of 27 countries had only one study eligible to be included in this review. Early childhood caries prevalence ranges from these studies were highly variable, with no apparent differences in prevalence between developed and developing countries.

Table 1 shows that the range of ECC prevalence among the reported studies countries was extreme. For instance, the range of caries prevalence for 1 year olds was between 1% and 96% derived from reports from the United States and Brazil, respectively; for 2 years old, the range was 6–88%, derived from Nigeria and Brazil, respectively; for 3 years old, the range was 4–80% derived from the United States and Salvador, respectively; for 4 years old, the range was 12–80% derived from France and Salvador, respectively; and for 5 years old, the range was 21–97%, derived from Nigeria and Salvador, respectively.

Figure 2 illustrates the ECC prevalence in three developed and three developing countries with sufficient data, to show the ranges and median values for ECC prevalence in children %3C;3 years old and between 3 years and 6 years old. The median prevalence values in many of the ranges are closer to one side of the range, indicating that the median data for prevalence may give a different understanding of each country’s data than the reported ranges in caries prevalence.

Figure 3 illustrates the change in caries prevalence in developed and developing countries as reported by the year of study publication date. There is no clear trend in the increase or decrease of ECC prevalence over the 20 years. It should be noted that since 2013, reports have been exclusive from developing countries.

The ECC ranges and median values of the three countries with the largest number of reports, India, the United States, and Brazil, are presented in Figure 4 that shows the variances within and between countries. The median values of ECC prevalence from USA studies have the most significant increase (approximately 20%) in children between ages 3 and 4. Median values in caries prevalence from Brazil were higher in all the ages than the USA’s median values. There was no evident caries prevalence by age group for India’s studies.

DISCUSSION

Reported ECC prevalence ranges present extreme geographical and age variations that can be lessened by displaying the findings graphically and by using summary statistics. Accordingly, using median values, this mapping review found higher ECC prevalence in 3–6 years old; no differences in ECC prevalence associated with countries’ economic status; and greater numbers studies from developing countries in the past 7 years.

We did not find differences in the prevalence of ECC between developed and developing countries. According to previous reports, countries with universal health care coverage were more likely to have lower ECC prevalence;^13,14 countries with higher gross national income reported a higher prevalence of ECC;^15,16 income inequality measures were reported to be inversely related to caries prevalence in 5–6 years old children countries with more remarkable economic growth have higher ECC prevalence,¹⁷ and a higher percentage of caries were reported in children living in poor social conditions such as in urban slums due to high sugar consumption in their diet.¹⁸ In a recent report, Folayan et al.¹⁴ noted a significant variation in the percentage of 3- to 5-year-olds with ECC in low and middle-income countries using the indicator for monetary poverty. However, from the 59 included studies in this study, we did not find sufficient data to support the concept that ECC prevalence was associated with socioeconomic factors, reinforcing the need for further research in this area.

The considerable variation in reported ECC prevalence that we found, perhaps, can be attributed to differences in the epidemiological study methods, variation in ECC diagnosis criteria, thresholds, and examination conditions. Additionally, there have been only a few comparative studies to evaluate global variations.¹⁰

Early childhood caries prevalence data were explored by ranges and calculated median values for each country and age group in the present study. Median values instead of means were used because of the highly skewed values within each range. The findings between ranges and median values showed different sensitivities and possibly different inferences. For instance, the median prevalence value for children under 3 years old calculated from Brazil’s studies is 27, ranging from 2 to 96%.^19–23 Perhaps, the report of ECC prevalence by median values rather than ranges may better reflect the caries prevalence for a country and age group more accurately.

The 59 included studies’ findings were arranged chronically from 1999 to 2019 to explore whether ECC prevalence temporally has changed temporally. Although it is evident that there are more reports of ECC caries prevalence after 2012, there is no clear pattern of change in the range of prevalence data over the 19 years examined. This finding can be compared to the US National Health and Nutrition Examination Survey (NHANES) surveys of children aged 2–5, collected from six surveys showing that the mean decayed and filled surfaces (dfs) were consistent between 2 and 3 between 1988 and 2012.²⁴

This review has certain limitations, resulting from both the methodology and the nature of evidence. The review may be open to bias since it combined two literature searches and only included English reports. Most importantly, ECC prevalence studies results may not be generalizable, even for a specific country, since populations may have been selected from high prevalence areas that would increase the possibility of over-estimating ECC prevalence.¹⁰ For example, Canada’s two ECC prevalence studies^25,26 refer to indigenous populations that may not represent the true ECC prevalence for preschool children in Canada. Another limitation is that ECC prevalence studies often are convenience samples and may have vastly different sample sizes. We only included studies reporting %3E;100 subjects, yet the data in the present and the included studies do not factor in the sample sizes. Lastly, many of the included studies do not address the training and calibration of examiners, standard methods, or diagnostic criteria, limiting the reports’ validity.

CONCLUSION

This mapping review of the global prevalence of ECC, between 1999 and 2019, found extreme ranges in caries prevalence that could be better understood by calculating the median prevalence values for countries. The differences in ECC’s prevalence for developed and under-development countries were not evident. Many of the included studies appear to have issues regarding generalizability, use of convenience samples, lack of reporting of training and calibration of examiners, and variations in diagnostic criteria. This mapping review may guide ECC’s global prevalence and provide some understanding of the resources and services to reduce preschool children’s caries burden.

CLINICAL SIGNIFICANCE

The global ECC prevalence ranges are extreme. Median data may provide a structure for future epidemiological studies to optimizing healthcare resources for caries interventions globally.

REFERENCES

1. Drury TF, Horowitz AM, Ismail AI, et al. Diagnosing and reporting early childhood caries for research purposes. A report of a workshop sponsored by the National Institute of Dental and Craniofacial Research, the Health Resources and Services Administration, and the Health Care Financing Administration. J Public Health Dent 1999;59(3):192–197. DOI: 10.1111/j.1752-7325.1999.tb03268.x.

2. Li Y, Wang W. Predicting caries in permanent teeth from caries in primary teeth: an eight-year cohort study. J Dent Res 2002;81(8):561–566. DOI: 10.1177/154405910208100812.

3. Gomes MC, Pinto-Sarmento TC, de A, et al. Impact of oral health conditions on the quality of life of preschool children and their families: a cross-sectional study. Health Qual Life Outcomes 2014;12(1):55. DOI: 10.1186/1477-7525-12-55.

4. Casamassimo PS, Thikkurissy S, Edelstein BL, et al. Beyond the dmft: the human and economic cost of early childhood caries. J Am Dent Assoc 2009;140(6):650–657. DOI: 10.14219/jada.archive.2009.0250.

5. Clarke M, Locker D, Berall G, et al. Malnourishment in a population of young children with severe early childhood caries. Pediatr Dent 2006;28(3):254–259.

6. Acs G, Lodolini G, Kaminsky S, et al. Effect of nursing caries on body weight in a pediatric population. Pediatr Dent 1992;14(5):302–305.

7. Singh N, Dubey N, Rathore M, et al. Impact of early childhood caries on quality of life: child and parent perspectives. J Oral Biol Craniofac Res 2020;10(2):83–86. DOI: 10.1016/j.jobcr.2020.02.006.

8. McGrath C, Broder H, Wilson-Genderson M. Assessing the impact of oral health on the life quality of children: implications for research and practice. Community Dent Oral Epidemiol 2004;32(2):81–85. DOI: 10.1111/j.1600-0528.2004.00149.x.

9. Tinanoff N, Baez RJ, Diaz Guillory C, et al. Early childhood caries epidemiology, aetiology, risk assessment, societal burden, management, education, and policy: Global perspective. Int J Paediat Dentis 2019;29(3):238–248. DOI: 10.1111/ipd.12484.

10. El Tantawi M, Folayan MO, Mehaina M, et al. Prevalence and data availability of early childhood caries in 193 united nations countries, 2007-2017. Am J Public Health 2018;108(8):1066–1072. DOI: 10.2105/AJPH.2018.304466.

11. Principles of Epidemiology | Lesson 2 - Section 8 [Internet]. 2020 [cited 2020 Sep 10]. Available from: https://www.cdc.gov/csels/dsepd/ss1978/lesson2/section8.html.

12. Developing countries | Department of Economic and Social Affairs [Internet]. [cited 2020 Jul 28]. Available from: https://www.un.org/development/desa/dpad/tag/developing-countries/.

13. Markovic D, Soldatovic I, Vukovic R, et al. How much country economy influences ECC profile in Serbian children—a macro-level factor analysis. Front Public Health 2019;;7:285. Available from: https://www.frontiersin.org/articles/10.3389/fpubh.2019.00285/full.

14. Folayan MO, Alade M, Adeniyi A, et al. Association between early childhood caries and poverty in low and middle income countries. BMC Oral Health 2020;20(1):1–8. DOI: 10.1186/s12903-019-0991-2.

15. Ramji R, Carlson E, Brogårdh-Roth S, et al. Understanding behavioural changes through community-based participatory research to promote oral health in socially disadvantaged neighbourhoods in Southern Sweden. BMJ Open 2020;10(4):e035732. DOI: 10.1136/bmjopen-2019-035732.

16. Phantumvanit P, Makino Y, Ogawa H, et al. WHO global consultation on public health intervention against early childhood caries. Community Dent Oral Epidemiol 2018;46(3):280–287. DOI: 10.1111/cdoe.12362.

17. Masood M, Masood Y, Newton T. Impact of national income and inequality on sugar and caries relationship. Caries Res 2012;46(6):581–588. DOI: 10.1159/000342170.

18. Goyal A, Grover A, Gauba K, et al. A community-based pragmatic, controlled trial for preventing and reducing oral diseases among 1–6-year-old children visiting Anganwadi centers, under the integrated child development scheme, India. BMC Public Health 2019;19(1):1–8. DOI: 10.1186/s12889-019-7874-y.

19. Dos Santos Pinto G, de Ávila Quevedo L, Britto Correa M, et al. Maternal depression increases childhood dental caries: a cohort study in Brazil. Caries Res 2017;51(1):17–25. DOI: 10.1159/000449040.

20. Corrêa-Faria P, Martins-Júnior PA, Vieira-Andrade RG, et al. Factors associated with the development of early childhood caries among Brazilian preschoolers. Braz Oral Res 2013;27(4):356–362. DOI: 10.1590/S1806-83242013005000021.

21. Corrêa-Faria P, Paixão-Gonçalves S, Paiva SM, et al. Association between developmental defects of enamel and early childhood caries: a cross-sectional study. Int J Paediatr Dent 2015;25(2):103–109. DOI: 10.1111/ipd.12105.

22. Oliveira LB, Sheiham A, Bönecker M. Exploring the association of dental caries with social factors and nutritional status in Brazilian preschool children. Eur J Oral Sci 2008;116(1):37–43. DOI: 10.1111/j.1600-0722.2007.00507.x.

23. Rosenblatt A, Zarzar P. The prevalence of early childhood caries in 12- to 36-month-old children in Recife, Brazil. ASDC J Dent Child 2002;69(3):319–324,236.

24. NHANES - National Health and Nutrition Examination Survey Homepage [Internet]. 2020 [cited 2020 Nov 12]. Available from: https://www.cdc.gov/nchs/nhanes/index.htm.

25. Schroth RJ, Moffatt MEK. Determinants of early childhood caries (ECC) in a rural Manitoba community: a pilot study. Pediatr Dent 2005;27(2):114–120.

26. Schroth RJ, Moore P, Brothwell DJ. Prevalence of early childhood caries in 4 Manitoba communities. J Can Dent Assoc 2005;71(8):567.

27. Nunn ME, Dietrich T, Singh HK, et al. Prevalence of early childhood caries among very young urban Boston children compared with US children. J Public Health Dent 2009;69(3):156–162. DOI: 10.1111/j.1752-7325.2008.00116.x.

28. Nunn ME, Braunstein NS, Krall Kaye EA, et al. Healthy eating index is a predictor of early childhood caries. J Dent Res 2009;88(4):361–366. DOI: 10.1177/0022034509334043.

29. Alaki SM, Burt BA, Garetz SL. The association between antibiotics usage in early childhood and early childhood caries. Pediatr Dent 2009;31(1):31–37.

30. Phipps KR, Ricks TL, Manz MC, et al. Prevalence and severity of dental caries among American Indian and Alaska native preschool children. J Public Health Dent 2012;72(3):208–215. DOI: 10.1111/j.1752-7325.2012.00331.x.

31. Iida H, Auinger P, Billings RJ, et al. Association between infant breastfeeding and early childhood caries in the United States. Pediatrics 2007;120(4):e944–e952. DOI: 10.1542/peds.2006-0124.

32. Ramos-Gomez FJ, Tomar SL, Ellison J, et al. Assessment of early childhood caries and dietary habits in a population of migrant hispanic children in Stockton, California. ASDC J Dent Child 1999;66(6):395–403.,366.

33. Anderson L, Martin NR, Burdick A, et al. Oral health status of new hampshire head start children, 2007-2008. J Public Health Dent 2010;70(3):245–248. DOI: 10.1111/j.1752-7325.2009.00161.x.

34. Psoter WJ, Pendrys DG, Morse DE, et al. Associations of ethnicity/race and socioeconomic status with early childhood caries patterns. J Public Health Dent 2006;66(1):23–29. DOI: 10.1111/j.1752-7325.2006.tb02547.x.

35. Mangla RG, Kapur R, Dhindsa A, et al. Prevalence and associated risk factors of severe early childhood caries in 12- to 36-month-old children of Sirmaur district, Himachal Pradesh, India. Int J Clin Pediatr Dent 2017;10(2):183–187. DOI: 10.5005/jp-journals-10005-1431.

36. Priyadarshini HR, Hiremath SS, Puranik M, et al. Prevalence of early childhood caries among preschool children of low socioeconomic status in Bangalore city, India. J Int Soc Prev Community Dent 2011;1(1):27–30. DOI: 10.4103/2231-0762.86384.

37. Tyagi R. The prevalence of nursing caries in davangere preschool children and its relationship with feeding practices and socioeconomic status of the family. J Indian Soc Pedod Prev Dent 2008;26(4):153–157. DOI: 10.4103/0970-4388.44030.

38. Gopal S, Chandrappa V, Kadidal U, et al. Prevalence and predictors of early childhood caries in 3- to 6-year-old South Indian Children--a cross-sectional descriptive study. Oral Health Prev Dent 2016;14(3):267–273. DOI: 10.3290/j.ohpd.a35619.

39. Mahejabeen R, Sudha P, Kulkarni SS, et al. Dental caries prevalence among preschool children of Hubli: Dharwad city. J Indian Soc Pedod Prev Dent 2006;24(1):19–22. DOI: 10.4103/0970-4388.22829.

40. Singh S, Vijayakumar N, Priyadarshini HR, et al. Prevalence of early childhood caries among 3-5 year old pre-schoolers in schools of Marathahalli. Bangalore Dent Res J (Isfahan) 2012;9(6):710–714.

41. Sujlana A, Pannu PK. Family related factors associated with caries prevalence in the primary dentition of five-year-old children. J Indian Soc Pedod Prev Dent 2015;33(2):83–87. DOI: 10.4103/0970-4388.155108.

42. Arangannal P, Mahadev SK, Jayaprakash J. Prevalence of dental caries among school children in Chennai, based on ICDAS II. J Clin Diagn Res 2016;10(4):ZC09–ZC12. DOI: 10.7860/JCDR/2016/14731.7523.

43. Tanaka K, Miyake Y. Low birth weight, preterm birth or small-for-gestational-age are not associated with dental caries in young Japanese children. BMC Oral Health 2014;14(1):38. DOI: 10.1186/1472-6831-14-38.

44. Seki M, Yamashita Y. Decreasing caries prevalence in Japanese preschool children is accompanied with a reduction in mutans streptococci infection. Int Dent J 2005;55(2):100–104. DOI: 10.1111/j.1875-595x.2005.tb00041.x.

45. Nakayama Y, Mori M. Association of environmental tobacco smoke and snacking habits with the risk of early childhood caries among 3-year-old Japanese children. J Public Health Dent 2015;75(2):157–162. DOI: 10.1111/jphd.12085.

46. Ardenghi TM, Sheiham A, Marcenes W, et al. Maxillary anterior caries as a predictor of posterior caries in the primary dentition in preschool Brazilian children. J Dent Child (Chic) 2008;75(3):215–221.

47. Santos APP, dos, Soviero VM. Caries prevalence and risk factors among children aged 0 to 36 months. Pesqui Odontol Bras 2002;16(3):203–208. DOI: 10.1590/s1517-74912002000300004.

48. Moimaz SAS, Borges HC, Saliba O, et al. Early childhood caries: epidemiology, severity and sociobehavioural determinants. Oral Health Prev Dent 2016;14(1):77–83. DOI: 10.3290/j.ohpd.a34997.

49. Schroth RJ, Cheba V. Determining the prevalence and risk factors for early childhood caries in a community dental health clinic. Pediatr Dent 2007;29(5):387–396.

50. Du M, Luo Y, Zeng X, et al. Caries in preschool children and its risk factors in 2 provinces in China. Quintessence Int 2007;38(2):143–151.

51. Li Y, Zhang Y, Yang R, et al. Associations of social and behavioural factors with early childhood caries in Xiamen city in China. Int J Paediatr Dent 2011;21(2):103–111. DOI: 10.1111/j.1365-263X.2010.01093.x.

52. Zhou Y, Lin HC, Lo ECM, et al. Risk indicators for early childhood caries in 2-year-old children in southern China. Aust Dent J 2011;56(1):33–39. DOI: 10.1111/j.1834-7819.2010.01280.x.

53. Zhang S, Liu J, Lo ECM, et al. Dental caries status of Bulang preschool children in Southwest China. BMC Oral Health 2014;14(1):16. DOI: 10.1186/1472-6831-14-16.

54. Slabšinskienė E, Milčiuvienė S, Narbutaitė J, et al. Severe early childhood caries and behavioral risk factors among 3-year-old children in Lithuania. Medicina (Kaunas) 2010;46(2):135–141. DOI: 10.3390/medicina46020020.

55. Razmienė J, Vanagas G, Bendoraitienė EA, et al. Changes in caries prevalence and oral hygiene skills among preschool-aged children in Lithuania between 2000 and 2010. Medicina (Kaunas) 2012;48(7):364–370. DOI: 10.3390/medicina48070054.

56. Sowole CA, Sote EO. Early childhood caries: experience in Nigerian children at Lagos. Niger Postgrad Med J 2007;14(4):314–318.

57. Folayan MO, Kolawole KA, Oziegbe EO, et al. Prevalence, and early childhood caries risk indicators in preschool children in suburban Nigeria. BMC Oral Health 2015;15(1):72. DOI: 10.1186/s12903-015-0058-y . Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4486704/.

58. Olatosi OO, Inem V, Sofola OO, et al. The prevalence of early childhood caries and its associated risk factors among preschool children referred to a tertiary care institution. Niger J Clin Pract 2015;18(4):493–501. DOI: 10.4103/1119-3077.156887.

59. Ferro R, Besostri A, Olivieri A, et al. Preschoolers’ dental caries experience and its trend over 20 years in a North-East Italian health district. Eur J Paediatr Dent 2007;8(4):199–204.

60. Hattab FN, Al-Omari MA, Angmar-Månsson B, et al. The prevalence of nursing caries in one-to-four-year-old children in Jordan. ASDC J Dent Child 1999;66(1):53–58.

61. Dimitrova MM, Kukleva MP, Kondeva VK. Prevalence of early childhood caries and risk factors in children from 1 to 3 years of age in Plovdiv, Bulgaria. Folia Med (Plovdiv) 2002;44(1–2):60–63.

62. Doğan D, Dülgergil CT, Mutluay AT, et al. Prevalence of caries among preschool-aged children in a central Anatolian population. J Nat Sci Biol Med 2013;4(2):325–329. DOI: 10.4103/0976-9668.116995.

63. Namal N, Vehit HE, Can G. Risk factors for dental caries in Turkish preschool children. J Indian Soc Pedodont Prevent Dentis 2005;23(3):115. DOI: 10.4103/0970-4388.16881.

64. Leroy R, Bogaerts K, Martens L, et al. Risk factors for caries incidence in a cohort of Flemish preschool children. Clin Oral Investig 2012;16(3):805–812. DOI: 10.1007/s00784-011-0579-y.

65. Tsai AI, Chen C-Y, Li L-A, et al. Risk indicators for early childhood caries in Taiwan. Community Dent Oral Epidemiol 2006;34(6):437–445. DOI: 10.1111/j.1600-0528.2006.00293.x.

66. Nørrisgaard PE, Qvist V, Ekstrand K. Prevalence, risk surfaces and inter-municipality variations in caries experience in Danish children and adolescents in 2012. Acta Odontol Scand 2016;74(4):291–297. DOI: 10.3109/00016357.2015.1119306.

67. Jin B-H, Ma D-S, Moon H-S, et al. Early childhood caries: prevalence and risk factors in Seoul, Korea. J Public Health Dent 2003;63(3):183–188. DOI: 10.1111/j.1752-7325.2003.tb03497.x.

68. Droz D, Guéguen R, Bruncher P, et al. Epidemiological study of oral dental health of 4-year-old children in french nursery schools. Arch Pediatr 2006;13(9):1222–1229. DOI: 10.1016/j.arcped.2006.05.017.

69. Livny A, Assali R, Sgan-Cohen HD. Early childhood caries among a bedouin community residing in the eastern outskirts of Jerusalem. BMC Public Health 2007;7(1):167. DOI: 10.1186/1471-2458-7-167.

70. Wagner Y, Greiner S, Heinrich-Weltzien R. Evaluation of an oral health promotion program at the time of birth on dental caries in 5-year-old children in Vorarlberg, Austria. Community Dent Oral Epidemiol 2014;42(2):160–169. DOI: 10.1111/cdoe.12072.

71. Dabiri D, Fontana M, Kapila Y, et al. Community-based assessment and intervention for early childhood caries in rural El Salvador. Int Dent J 2016;66(4):221–228. DOI: 10.1111/idj.12228.

72. Elidrissi SM, Naidoo S. Prevalence of dental caries and toothbrushing habits among preschool children in Khartoum State, Sudan. Int Dent J 2016;66(4):215–220. DOI: 10.1111/idj.12223.

73. Hoffmeister L, Moya P, Vidal C, et al. Factors associated with early childhood caries in Chile. Gac Sanit 2016;30(1):59–62. DOI: 10.1016/j.gaceta.2015.09.005.

74. Hysi D, Caglar E, Droboniku E, et al. Dental caries experience among Albanian pre-school children: a national survey. Community Dent Health 2017;34(1):46–49. DOI: 10.1922/CDH_3940Hysi04.

75. Wyne AH. Caries prevalence, severity, and pattern in preschool children. J Contemp Dent Pract 2008;9(3):24–31. DOI: 10.5005/jcdp-9-3-24.

76. Senesombath S, Nakornchai S, Banditsing P, et al. Early childhood caries and related factors in Vientiane, Lao PDR. Southeast Asian J Trop Med Public Health 2010;41(3):717–725.

77. Masumo R, Bardsen A, Mashoto K, et al. Prevalence and socio-behavioral influence of early childhood caries, ECC, and feeding habits among 6-36 months old children in Uganda and Tanzania. BMC Oral Health 2012;12(1):24. DOI: 10.1186/1472-6831-12-24.

78. Šačić L, Marković N, Arslanagić Muratbegović A, et al. The prevalence and severity of early childhood caries in preschool children in the federation of Bosnia and Herzegovina. Acta Med Acad 2016;45(1):19–25. DOI: 10.5644/ama2006-124.152.