Relation between Socioeconomic Indicators and Children Dental Caries in Iran: A Systematic Review and Meta-analysis

Decomposition of economic inequalities in dental caries among Iranian schoolchildren

INTRODUCTION

Monitoring social inequalities in dental caries is crucial for establishing priorities in oral health systems. This study aimed to assess economic inequalities in dental caries and its contributing factors among Iranian schoolchildren.

METHODS

Data were obtained from the first phase of the Shahroud Schoolchildren Eye Cohort Study in 2015. A total of 4992 children aged 6-12 years old were included in the analysis. Dental examinations were conducted following the diagnostic methods and standards of the Oral Health Examination Survey, as recommended by the World Health Organization. The concentration index (C) was utilized to assess economic inequalities in dental caries. Additionally, the decomposition of C was employed to explain the determinants of the measured inequalities.

RESULTS

In total, 71.4% of the schoolchildren had dental caries in primary dentition (dft≥1), and 41.6% of the schoolchildren had dental caries in permanent dentition (DMFT≥1). The Cs of dft≥1, primary decayed teeth (pdt≥1), and permanent missing teeth (PMT≥1) were -0.136 (95% CI: -0.167, -0.104), -0.164 (95% CI: -0.194, -0.134), and -0.208 (95% CI: -0.262, -0.153), respectively, which indicates their more concentration among low-economic children. Conversely, pft≥1 and PFT≥1 had Cs of 0.327 (95% CI: 0.292, 0.361) and 0.218 (95% CI: 0.179, 0.256), showing more concentration among high-economic children. Basic health insurance coverage and age were the main contributors that explained 28.6% and 19.2% of the economic inequality in dft≥1, and 25.7% and 16.6% of the pdt≥1 inequality, respectively. Economic status, residence in rural areas, mother education, father education, and age were the main contributors to the measured inequality in pft≥1 by 80.5% and 26.5%, 21.9%, 22%, and -18.3%, respectively. Economic status, having a housekeeper mother, residence in rural areas, having basic health insurance coverage, mother education, and father education positively contributed to the measured inequality in PMT≥1 by 45.4%, 42.4%, 37.8%, 35.1%, 21.3%, and 15.2%, respectively, while age had a negative contribution of -19.3%. For PFT≥1, economic status, age, and father education accounted for 76%, 25.4%, and 20.3% of the measured inequality, respectively.

CONCLUSION

Pro-rich economic inequalities were observed in children's primary and permanent teeth caries. Thus, government interventions to reduce these inequalities should aim to expand the coverage of basic and supplementary health insurance in line with increasing the coverage of dental health costs in these plans, training and providing access to required dental health services for low-socioeconomic children, including the poor, rural, and those who have low-educated parents and a housekeeper mother, especially at younger ages.

Evaluation of the Effectiveness of Children's Dental Care Programs: A Retrospective Study

This study aimed to evaluate the long-term impact of children's dental care programs on children and adolescents to reduce oral health inequalities. It measured and assessed the improvement effects of children's dental care programs on the oral health of children and adolescents as part of the efforts to decrease oral health disparities in this age group. It included 406 individuals who participated in student and children's dental care program between 2013 and 2019 at screening facilities in Gwangjin-gu, Seoul. A frequency analysis was conducted for demographic characteristics, and a binary logistic regression analysis was performed to identify factors influencing the prevalence of dental caries as the dependent variable. The data were analyzed using PASW Statistics with the statistical significance level set at α = 0.05. Regarding oral health status based on the frequency of participation in children's dental care program for children and adolescents, participants with seven or more sessions had lower prevalence rates of dental caries, malocclusion, and periodontal disease than those with only one session. Second, when comparing oral health status in children's dental care program between primary and adolescent age groups, individuals under continuous oral health care showed a decrease in permanent teeth affected by dental caries, dental caries prevalence, and malocclusion prevalence (excluding primary school age). Third, a binary logistic regression analysis revealed significant influences (p < 0.05) of the developmental stage and frequency of program participation on dental caries prevalence. Children's dental care programs are essential for alleviating oral health inequalities among children and adolescents and preventing oral diseases. Furthermore, the developmental stage of children and the frequency of program participation are crucial factors in preventing oral conditions, such as dental caries.

Overadjustment bias in systematic reviews and meta-analyses of socio-economic inequalities in health: a meta-research scoping review

BACKGROUND

Overadjustment bias occurs when researchers adjust for an explanatory variable on the causal pathway from exposure to outcome, which leads to biased estimates of the causal effect of the exposure. This meta-research review aimed to examine how previous systematic reviews and meta-analyses of socio-economic inequalities in health have managed overadjustment bias.

METHODS

We searched Medline and Embase until 16 April 2021 for systematic reviews and meta-analyses of observational studies on associations between individual-level socio-economic position and health outcomes in any population. A set of criteria were developed to examine methodological approaches to overadjustment bias adopted by included reviews (rated Yes/No/Somewhat/Unclear).

RESULTS

Eighty-four reviews were eligible (47 systematic reviews, 37 meta-analyses). Regarding approaches to overadjustment, whereas 73% of the 84 reviews were rated as Yes for clearly defining exposures and outcomes, all other approaches were rated as Yes for <55% of reviews; for instance, 5% clearly defined confounders and mediators, 2% constructed causal diagrams and 35% reported adjusted variables for included studies. Whereas only 2% included overadjustment in risk of bias assessment, 54% included confounding. Of the 37 meta-analyses, 16% conducted sensitivity analyses related to overadjustment.

CONCLUSIONS

Our findings suggest that overadjustment bias has received insufficient consideration in systematic reviews and meta-analyses of socio-economic inequalities in health. This is a critical issue given that overadjustment bias is likely to result in biased estimates of health inequalities and accurate estimates are needed to inform public health interventions. There is a need to highlight overadjustment bias in review guidelines.

Family income modifies the association between frequent sugar intake and dental caries

AIM

The aim of this cross-sectional study was to investigate whether family income modifies associations between dental caries and sex, age, mother's education, type of preschool, sugar intake, and toothbrushing.

BACKGROUND

Dental caries is a multifactorial dyanamic disease primarily mediated by biofilm and sugar.

DESIGN

A randomly selected sample of 308 Brazilian preschool children aged 1-3 years underwent a clinical oral examination for the assessment of moderate/extensive dental caries using codes 3-6 of the International Caries Detection and Assessment System. Mothers were asked to fill out a form addressing the child's demographic and socioeconomic characteristics as well as the frequency of sugar intake. Statistical analysis involved descriptive statistics, the chi-squared test, and Poisson regression models.

RESULTS

The prevalence of moderate/extensive dental caries was 42.5%. The adjusted model revealed that within low-income families (<2 times the monthly minimum wage), the prevalence of dental caries was higher among children with a high frequency of sugar intake (≥ twice per day) than in those with a low frequency of sugar intake (< twice a day) (RR = 1.79; CI: 1.38-2.33). In families with higher income (≥2 times the monthly wage), no significant association between sugar intake and dental caries was, however, found.

CONCLUSIONS

In conclusion, monthly family income can modify the association between the high frequency of sugar intake and dental caries.

Structuring of the effects of oral health literacy on dental caries in 12-year-old adolescents

OBJECTIVES

To explore the pathways by which oral health literacy is associated with dental caries in adolescents, assessing direct and indirect effects of family cohesion and socioeconomic status.

METHODS

A population-based, representative cross-sectional study was conducted with 740 12-year-old adolescents in Campina Grande, Brazil. Parents/guardians answered a sociodemographic questionnaire. Adolescents answered validated questionnaires addressing family cohesion and oral health literacy. Dental caries was diagnosed using Nyvad criteria. Two dentists underwent training exercises for the diagnosis and administration of the questionnaires (k > 0.80). Descriptive analysis was followed by the use of structural equation modelling to determine direct and indirect associations between the variables incorporated into the theoretical model of the study (95% CI).

RESULTS

Oral health literacy (standardized coefficient: -3.472, p < .01) and mother's schooling (standardized coefficient: -0.405, p < .01) were directly associated with dental caries, whereas family cohesion and socioeconomic status exerted an indirect effect on the occurrence of dental caries in the adolescents.

CONCLUSIONS

Sociodemographic factors, family characteristics and oral health literary are associated with dental caries in 12-year-old adolescents.

Socio-economic inequality in reported dental self-care behavior among Iranian households: a national pooled study

BACKGROUND

Setting out effective prevention strategies in dental diseases needs recognition related factors of the prevention behaviors and targeting the most disadvantaged groups in the term of dental hygiene. This study aimed to investigate socio-economic inequality in the dental self-care status (DSS) of Iranian households and decompose the measured inequality into its contributors.

METHOD

In this cross-sectional study pooled data was extracted from Households Income and Expenditure Surveys (HIESs) conducted in Iran from 2012 to 2017. The index of socioeconomic status (SES) for each household was constructed using principal components analysis (PCA). We used Wagstaff normalized concentration index as a measure of socioeconomic inequality in dental self-care. Decomposition analysis was applied to determine the main factors contributed to the measured inequality.

RESULTS

The prevalence of dental self-care in the whole population was 40.56%. The total concentration index was 0.271 (CI: 0.266, 0.275). The results of decomposition analysis for the measured inequality showed that SES, was the highest positive contributors (90.19 %) followed by sex of household's head (12.15 %), place of residence (11.79 %), and education level of household's head (11.71 %). Furthermore, the province of residence had the highest negative contribution (-11.37) to the inequality.

CONCLUSION

The findings of this study showed that a huge portion of the observed inequality was explained by SES that might give us a policy recommendation: There is room for improving dental health and reducing inequality in dental self-care by paying more attention to SES-disadvantaged households.

Perspectives on Social and Environmental Determinants of Oral Health

Most oral conditions have a multifactorial etiology; that is, they are modulated by biological, social, economic, cultural, and environmental factors. A consistent body of evidence has demonstrated the great burden of dental caries and periodontal disease in individuals from low socioeconomic strata. Oral health habits and access to care are influenced by the social determinants of health. Hence, the delivery of health promotion strategies at the population level has shown a great impact on reducing the prevalence of oral diseases. More recently, a growing discussion about the relationship between the environment, climate change, and oral health has been set in place. Certainly, outlining plans to address oral health inequities is not an easy task. It will demand political will, comprehensive funding of health services, and initiatives to reduce inequalities. This paper sought to give a perspective about the role of social and physical environmental factors on oral health conditions while discussing how the manuscripts published in this Special Issue could increase our knowledge of the topic.

Effects of health-promoting school strategy on dental plaque control and preventive behaviors in schoolchildren in high-caries, rural areas of Taiwan: a quasi-experimental design

Background

We evaluated the effects of health-promoting school (HPS) strategy on plaque control and behavior change in high-caries schoolchildren in Taitung, Taiwan.

Methods

A quasi-experimental design was adopted; six intervention schools (intervention group [IG]) and six comparison schools (comparison group [CG]) were selected from elementary schools with higher-than-average caries rates (> 68%). The IG was selected using cluster sampling, and the CG was selected to match the IG. In total, the IG and CG groups included 166 and 174 children each. The selected schools implemented the HPS framework for 3 months in the 2019 academic year. An oral examination of dental plaque was administered, and a self-administered questionnaire regarding knowledge, attitude, self-efficacy, and behaviors was distributed at baseline and at 2-week follow-up. A linear and logistic regression model using generalized estimating equations (GEEs) was used to analyze the differences between baseline and the follow-up data.

Results

Compared with the CG, the IG had a greater reduction in plaque index among second graders (β =  − 0.36) and plaque control record scores among second, fourth, and sixth graders (β =  − 27.48, − 26.04, and − 18.38, respectively). The IG also exhibited a greater increase at follow-up with respect to oral health–related knowledge among second graders and fourth graders (β = 1.46 and β = 0.92, respectively), attitude toward oral hygiene behaviors among sixth graders (β = 1.78), and self-efficacy regarding flossing for sixth graders (β = 1.43). Sixth graders in the IG were significantly more likely to brush before sleeping (adjusted odds ratio [aOR] = 2.99) and use fluoride toothpaste (aOR = 5.88) than those in the CG.

Conclusions

The HPS strategy was effective in reducing dental plaque and promoting preventing behaviors in rural high-caries schoolchildren.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01927-z.

Physical and mental growth and development in children with congenital hypothyroidism: a case-control study

Introduction

The clinical complications of congenital hypothyroidism such as brain disorders are very subtle and are not recognizable in infancy period. They are recognizable when it is too late for treatment or prevention. General screening of newborns is effective in diagnosing congenital hypothyroidism and initiating initial treatment. The aim of this study is to compare the physical and mental growth pattern of children with congenital hypothyroidism with healthy ones.

Methods

This case–control study was performed on 34 patients and 68 healthy children who were matched in terms of inclusion and exclusion criteria. Children development screening test (ASQ), children development assessment test (Bayley), preschool Wechsler intelligence scale (WPPSI) and age and steps questionnaire of emotional social development (ASQ-SE) were completed by trained questioners. Data were analyzed using STATA software.

Results

The results indicated that there was no significant difference between the mean of verbal (P = 0.77), non-verbal (P = 0.81) and general (P = 0.66) IQ in permanent and transient patients and healthy individuals. Also, there was no significant difference between the mean of different ranges of ASQ test (including communication, delicate and large movements, problem solving and social) at 12 months and 42 months (P < 0.05). According to Bayley test, there was no significant difference between the cases (permanent and transient) and controls in the cognitive (P = 0.42) and expressive (P = 0.38) categories. The difference was significant in the perceptual (P = 0.011), large (P = 0.03) and delicate (P = 0.04) movements categories.

Conclusion

This study emphasized on the high effectiveness of neonate hypothyroidism screening program, so that the difference between 3.5 years old children with and without this disease has decreased significantly. Early diagnosis of the patients, while creating beneficial effects for patients and increasing quality of life, cause reduction in the long-term costs of the health system.

What makes inequality in the area of dental and oral health in developing countries? A scoping review

Background

Equity in health is an important consideration for policy makers particularly in low and middle income developing country. The area of oral and dental health is not an exception. This study is conducted to explore the main determinants that make inequality in oral and dental health area in developing countries.

Methods

This was a scoping review applying the framework enhanced by Levac et al. Four databases of Scopus, PubMed, WOS and ProQuest were systematically searched applying to related keywords up to 27.11.2020. There restriction was placed in the English language but not on the study design. All the related studies conducted in the low or middle income developing countries were included. A qualitative thematic analysis was applied for data analysis and a thematic map was presented.

Results

Among 436 articles after excluding duplications, 73 articles were included that the number of publications from Brazil was greater than other developing countries (33.33%). Thematic analysis of the evidence has led to 11 determinants that may result in inequality in oral and dental health services in developing countries including personal characteristics, health status, health needs and health behaviours, social, economic, cultural and environmental factors, as well as insurance, policies and practices and provided related factors.

Conclusion

The policymakers in the low and middle income developing countries should be both aware of the role of inequality determinants and also try to shift the resources to the policies and practises that can improve the condition of population access to oral and dental services the same as comprehensive insurance packages, national surveillance system and fair distribution of dentistry facilities. It is also important to improve the population’s health literacy and health behaviour through social media and other suitable mechanisms according to the countries’ local contexts.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12962-021-00309-0.

The effect of Iran's health transformation plan on hospital performance: Kerman province

Iran has performed Health Transformation Plan (HTP) from 2014 to obtain its defined goals. This study assesses and compares university and non-university hospitals' efficiency and productivity in Kerman provinces, Iran. The data of 19 selected hospitals, two years before and two years after Health Transformation Plan, was collected in this cross-sectional study. These data included the variables of physician and nurse number, and active beds as inputs and bed occupancy rate and inpatient admission adjusted with the length of stay as outputs. Data Envelopment Analysis method used to measure hospital efficiency. Malmquist Productivity Index is used to measure the efficiency change model before and after the plan. The efficiency and effect of the plan on hospitals' efficiency and productivity were assessed using R software. The results indicated that all hospitals' average efficiency before the HTP was 0.843 and after the HTP was increased to 0.874. However, it was not significant (P>0.05). Productivity also had a decreasing trend. Based on the DEA method results, it was found that university and non-university hospitals' efficiency and productivity did not increase significantly after the HTP. Therefore, it is recommended that attention be paid to hospitals' performance indicators regarding how resources are allocated and decisions made.

Path analysis of skin cancer preventive behavior among the rural women based on protection motivation theory

BACKGROUND

Determining the effective factors on the adoption of preventive behaviors capable of reducing the risk of skin cancer is an important step in designing interventions to promote these behaviors. Based on the protection motivation theory, the present study is aimed to conduct a path analysis of skin cancer preventive behaviors in rural women to explore these factors.

METHODS

In this cross-sectional study, 243 rural women were randomly selected from the west of Iran to receive a valid and reliable questionnaire assessing constructs from the protection motivation theory, as well as demographic information. Fully completed questionnaires were returned by 230 women and the data were analyzed by SPSS 22 and LISREL8.8.

RESULTS

Concerning skin cancer preventive behaviors, 27.8% of women wore sun-blocking clothing when working under the sun, 21.7% used sunscreen cream, 5.7% wore a cap, and 4.8% used gloves and sunglasses. Protection motivation theory and per capita income explained 51% of motivation variance and 25% of the variance of skin cancer preventive behaviors. The response efficacy construct was the strongest predictor of the motivation of protection (ß = - 0.44, p < 0/001). Per-capita income (ß = - 0.34, p < 0/001) and motivation (ß = - 0.33, p < 0/001) were the strongest predictors of these behaviors.

CONCLUSIONS

This study showed that protection motivation theory is efficient in predicting skin cancer preventive behaviors and the interventions can be designed and implemented by this theory. Proper planning is also necessary for promoting these behaviors among people with low per-capita income.

Did the extended coverage policy contribute to alleviating socioeconomic inequality in untreated dental caries of both children and adolescents in South Korea?

Background

Dental sealants have been covered by the National Health Insurance Service (NHIS) since December 2009 in South Korea. This study aims to determine whether the socioeconomic inequality in untreated dental caries decreased after implementing the extended coverage policy for dental sealant.

Methods

The data were derived from the fourth (2007–2009) and sixth (2013–2015) waves of the Korean National Health and Nutrition Examination Survey (KNHANES) conducted by the Korea Centers for Disease Control and Prevention (KCDC). Dental caries and sealant experience by income quartiles were tested using the Rao-Scott chi-squared test. In order to examine socioeconomic inequalities and their trends over time, the prevalence ratios (PRs), slope index of inequality (SII), and relative index of inequality (RII) were estimated for each wave and age group. All analyses were conducted using SAS version 9.3.

Results

The adjusted PRs of untreated dental caries and sealants in the poorest in the aged 6–11 group were significantly higher and lower, respectively, compared to the most affluent quartile group for the fourth wave; however, all significant differences disappeared for the sixth wave, after the sealant coverage. The gap between the lowest and the highest was similar for the aged 12–18 group but it widened in the untreated dental caries even after the sealant coverage. The statistical significance of the PRs was maintained at the sixth wave for both caries and sealants. Children showed decreases in both SII and RII over time so its significance disappeared. The SII among adolescents decreased over time but the RII of untreated dental caries increased.

Conclusions

This study found that the NHIS coverage expansion of dental care had a positive effect on overall status in dental health among children and adolescents. However, younger children benefited more in terms of inequalities. Our findings indicate that strategies to enhance access to preventive dental services should consider the differential effects for the vulnerable population in terms of socioeconomic status and age from the beginning stage of the policy.

Association between early childhood caries and poverty in low and middle income countries

Background

The aim of this study was to assess the relationship between early childhood caries (ECC) in 3–5-year-old children, seven indicators of poverty and the indicator of monetary poverty in low- and middle-income countries (LICs, MICs).

Methods

This ecologic study utilized 2007 to 2017 country-level data for LICs and MICs. Explanatory variables were seven indicators of poverty namely food, water, sanitation, health, shelter, access to information, education; and monetary poverty. The outcome variable was the percentage of 3–5-year-old children with ECC. A series of univariate general linear regression models were used to assess the relationship between the percentage of 3–5 year-old children with ECC and each of the seven indicators of poverty, and monetary poverty. This was followed by multivariable regression models to determined the combined effect of the seven indicators of poverty, as well as the combined effect of the seven indicators of poverty and monetary poverty. Adjusted R² measured models’ ability to explain the variation among LICs and MICs in the percentage of 3–5-year-old children with ECC.

Results

Significantly more people had food, sanitation, shelter, access to information, education and monetary poverty in LICs than in MICs. There was no difference in the prevalence of ECC in 3–5-year-old children between LICs and MICs. The combination of the seven indicators of poverty explained 15% of the variation in the percentage of 3–5-year-old children with ECC compared to 1% explained by monetary poverty. When the seven indicators of poverty and the indicator for monetary poverty were combined, the amount of variation explained by them was 10%. Only two of the poverty indicators had a direct relationship with the percentage of children with ECC; there was a higher percentage of ECC in countries with higher percentage of population living in slums (B = 0.35) and in those countries with higher percentage of the population living below poverty lines (B = 0.19). The other indicators had an inverse relationship.

Conclusion

The use of multiple indicators to measures of poverty explained greater amount of variation in the percentage of 3–5-year-olds with ECC in LICs and MICs than using only the indicator for monetary poverty.

Evaluation of risk factors in caries formation in children

Background/Aim: The aim of this study was to evaluate the risk factors in caries formation and relationships between each other in children. Material and Methods: A total of 84 children aged between 5-15 years were included in the study. The children were randomly selected among the patients who came to the clinic. Oral disorders and oral hygiene were evaluated with the oral examination. Examination of the children was carried out by two calibrated pediatric dentists. Plaque index, dmf-t index (decay-missed-filled primary tooth) and DMF-T index (decay-missed-filled permanent tooth) scores were evaluated by clinical examination. Plaque index was evaluated using Sillness & Loe plaque index. In addition, a questionnaire was performed about children's age, tooth brushing habits, sweet consumption, dentist visit and dental treatment experience. Statistical analysis was conducted with Mann Whitney-U test, Chi-Square test, Independent t-test and Correlation test. Results: When the survey data is examined, there was no significant difference between boy and girl patients regarding dmft, DMFT, frequency of tooth brushing, sweet consumption and plaque index scores (p>0,05). There was no relationship between frequency of sweet consumption and DMF-T, dmf-t and plaque index scores (p>0,05). No significant relationship was found between the frequency of tooth brushing and DMF-T and dmf-t scores (p>0,05). The examinations were revealed that there were no children with regular tooth brushing habits and the plaque index scores of children with irregular tooth brushing habit was lower than the children with no brushing habits (p<0,05). In addition, a positive correlation was also observed between age and plaque index and DMFT scores. However, a negative correlation was observed between age and dmft scores. Conclusions: It is observed that there was a significant relationship between tooth brushing habits and plaque index values of children.

Dental caries experience and socio-economic status among Iranian children: a multilevel analysis

BACKGROUND

Socio-economic factors are considered as main determinants causing disparities in oral health across different countries. The aim of the present study was to investigate the associations of social and economic factors with dental caries experience among 6- and 12-year-old Iranian children.

METHODS

In this cross-sectional study, a total of 31,146 students, aged 6 and 12 years old, were enrolled from all (31) provinces in Iran. Based on the standardized World Health Organization (WHO) criteria for oral health surveys, dental caries indices in primary and permanent teeth were assessed by clinical examination in schools. Data on socio-economic status was obtained from the modified WHO questionnaire and national data bank. The decayed, missing and filled teeth (dmft/DMFT) indices for primary and permanent dentition were compared at the individual and provincial levels using multilevel regression analysis. Poisson regression analysis was used to evaluate the association of social (demographic and behavioral) determinants with dental caries indices among individuals. To assess the causes of difference in dental caries indices across provinces, justifiable economic factors were also analyzed using poisson regression analysis.

RESULTS

The mean (SE) of dmft and DMFT were 5.84 (0.05) and 1.84 (0.03), for 6-and 12-year-old children, respectively. The differences of dental caries indices were statistically significant among provinces. Higher level of parental education was negatively related to dental caries indices of both age groups. Rural residency was positively and dental flossing was reversely associated with dmft index of 6-year-old children. Negative associations were found between frequency of tooth brushing and preventive dental utilization with dmft and DMFT indices. Gross Domestic Product (GDP) index had negative and Consumer Price Index (CPI) had positive associations with dmft and DMFT indices in both age groups. However, positive relationships were observed between Gini index with DMFT index among 12-year-old children; as well as between the number of dentists per capita with dmft index among 6-year-old children.

CONCLUSION

Socio-demographic and behavioral factors were found to be associated with dental caries experience. However, economic indicators had the greatest importance.