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Abstract
Background Dental caries is a global public health problem, especially for young children. This study aimed to assess the prevalence of dental caries and its associated factors among preschool children in Mizan Aman town, Southwest Ethiopia.
Methods A school-based cross-sectional study was conducted from 1 October to 1 December 2022. A total of 354 children and their parents participated using simple random sampling techniques. Data were collected through an oral clinical examination, interviewing the parents and measuring the anthropometry of the children.
Results The prevalence of dental caries was 36.4% (95% CI 31.2% to 41.8%). Night feeding (adjusted OR (AOR)=3.98, 95% CI 1.56 to 10.15), children who did not brush their teeth under parental supervision (AOR=2.98, 95% CI 1.60 to 5.57), body mass index (AOR=3.48, 95% CI 1.30 to 9.41) and history of dental visits (AOR=3.05, 95% CI 1.61 to 5.81) were significantly associated with dental caries.
Conclusion The prevalence of dental caries in preschool children was found to be high. Children who did not brush their teeth under parental supervision, who had experience of night feeding, who had a high body mass index and who had a history of dental visits were at risk for dental caries. Prevention of those identified modifiable risk factors should be considered to reduce dental caries.
- Dentistry
Data availability statement
Data are available upon reasonable request.
This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.
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WHAT IS ALREADY KNOWN ON THIS TOPIC
Early childhood caries (ECC) is a serious public health problem globally.
A prior study was done on the determinants of ECC in Ethiopia using a case–control study design.
Research on the prevalence of dental caries among preschool children is not done in Ethiopia.
WHAT THIS STUDY ADDS
The prevalence of dental caries in this study was 36.4%.
Night feeding, toothbrushes under parental supervision, body mass index and history of dental visits were the identified factors for preschool dental caries in Ethiopia.
HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY
Good dietary habits and oral hygiene are required to reduce the risk of ECC.
Introduction
Dental caries is a common oral health problem that affects preschool and younger children globally.1 Early childhood caries (ECC) is the term for dental caries in young children’s primary dentition. ECC is defined as the presence of one or more missing, decayed or filled tooth surfaces in any primary tooth in a child at 71 months of age or younger.2
Dental caries affects almost half of preschool children globally, with geographical variations.3 Based on the findings of two African studies, the dental caries prevalence in Tanzania and Tunisia was 44% and 45%, respectively.4 5
Dental caries is a multifactorial disease that results from the interaction of microbes with fermentable carbohydrates through host factors, such as oral hygiene practices, consumption of a sweet diet, family income and health service utilisation.6 Research in Dessie town, northeastern Ethiopia, found that dental caries were affected by maternal educational level, birth order, time of bottle feeding, sweet diet and soft drink utilisation.7
Children with dental caries suffer ranging from local pain to more severe problems such as feeding difficulties, reduced appetite and sleeping, and gastrointestinal disorders.8 If it is left untreated, it may lead to long-term complications such as chronic systemic infection, delayed growth and development, low self-esteem, and a decrease in school performance.9 10 Additionally, ECC is thought to be an indicator of dental caries in permanent teeth.11
The government in Ethiopia has paid little attention to dental health problems. To the best of our knowledge, only one study on the risk factors of dental caries has been published in Ethiopia.7 In addition, the prevalence of ECC is not known. Thus, this study aimed to address this gap by determining the prevalence and factors affecting dental caries that were not identified in the previous study in preschool children.
Objectives
The aim of this study was to assess the prevalence of dental caries and associated factors among preschool children in Mizan Aman town, Southwest Ethiopia, 2022.
Materials and methods
Study design, setting and period
A school-based cross-sectional study design was conducted from 1 October to 1 December 2022, in Mizan Aman town. Miza Aman is the largest town in the Southwest Ethiopia People Region and one of the four capital cities in the region. The town is located 561 km southwest of Addis Ababa, the capital city of Ethiopia. The town had 15 kindergarten (KG) schools; of these, 13 were private, and the rest were public schools. The number of preschool children in the town was estimated to be 1280.
Population
All preschool children attending KG schools in Mizan Aman town were a study population. All children and their parents who were present during the data collection period were included in this study. Children with missing and filled teeth as a result of trauma were excluded from the study.
Sample size determination and sampling procedure
To calculate the required sample size, a pilot study was conducted on 30 participants, since no study had been done in Ethiopia to represent the proportion of dental caries. Two children and their parents were selected from each school using a simple random sampling technique. Based on the results of the pilot study, the prevalence of dental caries was 30%. The results of the pilot study were included in the analysis.
The sample size was calculated using a formula 
, the use of a 95% CI, a 5% margin of error (d) and a 30% prevalence (p) (from our pilot study). After adding 10% for the non-response, the total sample size was calculated to be 354. The sample size was proportionally allocated to all KG schools found in Mizan Aman town. The study participants were selected from each school using simple random sampling techniques.
Operational definitions
Preschool children: children who are between 36 and 71 months old.
ECC is defined as the presence of one or more decayed, missing or filled tooth surfaces in any primary tooth in a child of 71 months of age or younger.2
Data sources and measurement
Data were collected by an oral clinical examination, interviewing the parents and measuring the anthropometry of the children. The data were collected by two work teams independently. Each team consists of one dental doctor for dental examination and two trained BSc nurses to interview the parents and take anthropometric measurements of the children.
Dental examinations were performed using the WHO’s 2013 guidelines in a school setting12 by direct visual inspection and palpation of the buccal surfaces of all teeth by using natural light, disposable gloves and a spatula in the presence of their parents. Before an examination, pieces of sterile gauze were used to wipe and dry tooth surfaces. During an examination, the children were seated on a chair, using the ‘knee-to-knee’ position. A tooth was considered caries if there was visible evidence of one or more decayed, missing or filled tooth surfaces in any primary tooth. Decayed was recorded when a lesion present in a pit or fissure or on a smooth tooth surface had a detectable softened floor, undermined enamel or softened wall. A filled tooth was recorded when it contained one or more restorations and one or more areas that were decayed. A tooth was considered missing because of caries if a child had a history of pain and/or the presence of a cavity before extraction.
To ensure the reliability of the examination, inter-examiner and intra-examiner agreement was checked using Kappa test. Intra-examiner reliability was evaluated for each examiner by re-examining the 30 children on a different day in the same week, and the results were 0.85 and 0.91. Similarly, to evaluate inter-examiner reliability, 30 children were examined by two dental doctors independently, and the result was 0.85.
A structured English questionnaire was adapted from the previous studies,4 7 13–15 translated into Amharic by bilingual Amharic and English professionals, and then translated back to English by a freelance translator. Amharic is the official national language of Ethiopia.
The questionnaire had two parts. The first part includes sociodemographic-related characteristics of children and parents like educational status, monthly income, age of the child, sex of the child, order of birth, gestational age at birth and mode of delivery. The second part includes dietary and oral hygiene-related characteristics of the child, like duration of breast feeding, night feeding, history of dentist visits, consumption of sweet food, child teeth brushing under parent supervision and an oral health education programme.
To determine the nutritional status of the child, anthropometric measurements were used based on the WHO Growth Standards 2006.16 The nurses measured and recorded the weight and height of each child. Before every examination, calibration was done, and the children were asked to remove their shoes before measuring their weight and height. Children were also asked to maintain an upright and erect position with their feet together, and a horizontal headpiece was lowered into the children’s heads. Then the height was measured using a tape measure to the nearest 0.1 cm. The weight was also measured by a digital scale to the nearest 0.1 kg.
Body mass index (BMI) was calculated by entering the recorded weight and height of the children into the CDC online Child and Teen BMI Percentile Calculator.17 BMI was converted to BMI z-scores and percentile data based on children’s age and sex using an online calculator.17 Then BMI percentiles were classified into four categories: underweight, healthy, overweight and obese.18
Data processing and analysis
After coding, the data were entered using Epi-data V.3.2 and then exported to SPSS V.25.0 software for analysis. Descriptive statistics were calculated to obtain descriptive measures for the sociodemographic characteristics and other variables. Bivariate analysis was done to identify the crude association of variables with dental caries, and variables with p values ≤0.25 in the bivariate analysis were selected as candidates for the multivariable analysis. We examined interactions between history of dentist visits and toothbrushes under parental supervision, between oral health education and toothbrushes under parental supervision, as well as between oral health education and history of dentist visits. No significant interactions were found between the independent variables. The fitness of the logistic regression model was evaluated using a Hosmer-Lemeshow statistic greater than 0.05. The presence and strength of the association between dental caries and the predictors were assessed using adjusted ORs (AORs) with 95% CIs. Statistically, a significant association was declared when the 95% CI of the AOR did not contain 1. Finally, the results were presented in texts, figures and tables.
Results
Sociodemographic characteristics of children and parents
In the study, a total of 354 children participated, with a response rate of 93.3%. Of these, more than one-third, 112 (33.9%), of children were between 49 and 60 months old, and more than half, 201 (60.9%), were female. About one-third 121 (36.7%) of the children’s mothers did not attend formal education, and also one-third 99 (30%) of the children’s fathers did not attend formal education. About half 172 (52.2%) of children were delivered at term gestational age, and about two-thirds 240 (72.7%) of children were delivered by spontaneous vaginal delivery. More than half 181 (54.9%) of children had a second birth order (table 1).
Sociodemographic-related characteristics of the children and parents in Mizan Aman, Southwest Ethiopia, 2022 (n=330)
Dietary and oral hygiene-related characteristics
More than one-third 131 (39.7%) of the children were fed breast milk between 12 and 24 months, and the majority 292 (88.5%) of the preschool children did not feed at night. Most 260 (78.8%) of children did not consume sweet food. About two-thirds of 244 (73.9%) children brush their teeth with their parents’ supervision. About half 156 (47.3%) of children receive oral health education, and about two-thirds (245 (74.2%) of children have no history of dentistry. About two-thirds of 332 (70.2%) children had a healthy BMI (table 2).
Dietary and oral hygiene-related characteristics of the children in Mizan Aman, Southwest Ethiopia, 2022 (n=330)
Prevalence of dental caries among preschool children in Mizan Aman, Ethiopia, 2022.
Oral health status of the children
In this study, the prevalence of dental caries was 36.4% (95% CI 31.2% to 41.8%). Of the children who had dental caries, the majority 93 (77.5%) had decayed teeth, 27 (22.5%) had missed teeth and there were no filled teeth reported in this study (figure 1).
Factors associated with dental caries
According to this study, children who had dental caries were four times more likely to have been fed at night than not fed at night (AOR=3.98, 95% CI 1.56 to 10.15). Children who did not brush their teeth under parental supervision were three times more likely to develop dental caries as compared with the children who brushed their teeth under the supervision of their parents (AOR=2.98, 95% CI 1.60 to 5.57). Children who had dental caries were three times more likely to have visited the dentist at least once than never visited (AOR=3.05, 95% CI 1.61 to 5.81). Children who had dental caries were 3.4 times less likely to have been overweight or obese than underweight (AOR=3.48, 95% CI 1.30 to 9.41) (table 3) (online supplemental table 1).
Supplemental material
Factors associated with dental caries among preschool children in Mizan Aman, Southwest Ethiopia, 2022 (n=330)
Discussions
Even though dental caries is one of the major public health oral diseases, little attention has been given to preschool children in Ethiopia. Our study was designed to study the prevalence and risk factors of dental caries among preschool children in Mizan Aman town. The prevalence of dental caries in this study was 36.4% (95% CI 31.2% to 41.8%). This finding was in line with studies conducted in Italy (40.7%), Uganda (38 and 41%) and China (39.6%).19–21 However, the result of this study was lower than studies conducted in Tanzania (55.2%), Saudi Arabia (72.6%) and India (47.2%).5 15 22 On the other hand, the prevalence of dental caries in this study was higher than in studies done in Tunisia (20%), India (27.5%) and Japan (12.5%).14 23 24 The difference could be due to differences in knowledge, attitude and practices of the children and parents on oral hygiene since this study was done among urban preschool children. In addition, the different sociodemographics, materials and methods used might account for the difference.
This study showed that children who had dental caries were four times more likely to have been fed at night than those who were not fed at night. This was comparable with studies conducted in Ethiopia Dessie town, Niger and Brazil.4 7 13 A possible explanation could be that feeding at night decreases the clearance of liquid carbohydrates from the oral cavity due to decreased salivary production and flow at night.25
Children who had dental caries were three times more likely to have visited the dentist at least once than never visited. Similar findings have also established that there was a significant association between dental caries and a history of dental visits.24 This might be explained by the fact that most children see the dentist only for an existing dental problem, rather than for prevention and control purposes.
Children who had dental caries were 3.4 times less likely to have been overweight or obese than underweight. This finding is consistent with studies conducted in Sweden and Brazil that show low BMI is associated with dental caries in preschool children.26 27 This could be explained by the fact that overweight/obese children might consume more fatty foods, fried foods and unrefined carbohydrates, but not necessarily more foods high in sugar and refined carbohydrates. It could increase overweight/obesity, but not necessarily have a direct link to dental caries.28–30 Another possible explanation for the relationship is that saliva production increases due to increased food consumption in overweight/obese children.28 The protective effect of saliva as a mechanical cleanser and pH buffer could thus reduce the incidence of dental caries.28 31 Therefore, overweight/obesity has a protective effect on dental caries; however, this needs further investigation.
The findings of this study also indicated that children who did not brush their teeth under supervision were three times more likely to develop dental caries as compared with the children who brushed their teeth under the supervision of their parents. Similar findings have also been established that children who did not brush their teeth under supervision were more likely to develop dental caries as compared with the children who brushed their teeth under the supervision of their parents.14 15 The reason for this association could be that preschool children do not understand or have the manual dexterity to maintain good oral hygiene. Hence, parents are essential to reducing the risk of developing caries. Tooth brushing by parents has the potential to remove dental plaque more effectively by optimally saturating the oral environment.
In the previous study, consumption of sweet foods was reported as a contributing factor to dental caries.7 On the contrary, this study revealed that the consumption of sweet food was not independently associated with dental caries after controlling for other characteristics. This difference might be justified by the difference in sociodemographic characteristics of the study participants, sample size and methodology.
Limitations of the study
Identification of dental caries using a dental mirror and radiology was not possible due to a lack of instruments and a laboratory setup. Therefore, dental caries were identified only with clinical diagnosis, which might reduce the magnitude of dental caries.
Conclusion
In this study, the prevalence of dental caries in preschool children was found to be high. Children who did not brush their teeth under parental supervision, who had experience of night feeding, who had a high BMI, and who had a history of dental visits were at risk for dental caries. Thus, dietary habits and oral hygiene are important for the prevention of dental caries.
Data availability statement
Data are available upon reasonable request.
Ethics statements
Patient consent for publication
Ethics approval
This study involves human participants. Before data collection, ethical clearance was obtained from Mizan-Tepi University, College of Medicine and Health Science, with reference number 073/2022. Participants gave informed consent to participate in the study before taking part.
Acknowledgments
We would like to thank all the consultants, data collectors as well and study participants for making the research possible.
References
Supplementary materials
Supplementary Data
This web only file has been produced by the BMJ Publishing Group from an electronic file supplied by the author(s) and has not been edited for content.
Footnotes
Contributors AA developed the conception of the idea, wrote the proposal, and participated in the data collection and analysis. GFA participated in data analysis, report writing and prepared the manuscript. DG and MSA approved the proposal with some revisions and participated in manuscript development. All authors read and approved the final manuscript. AA is the study guarantor.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.
Provenance and peer review Not commissioned; externally peer reviewed.
Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.