Association of environmental tobacco smoke and snacking habits with the risk of early childhood caries among 3-year-old Japanese children

A systematic review and meta-analysis on early-childhood-caries global data

OBJECTIVES

The present study systematically reviewed and provided a meta-analysis on early childhood caries (ECC) global prevalence and its association with socioeconomic indicators, both geographical and regarding unemployment rate, national income as well as income inequalities.

METHODS

Only cross-sectional or cohort studies covering ECC prevalence and experience in children younger than 71 months, reporting sample size, diagnostic criteria and conducted in urban and rural communities were considered. No language restriction was selected. Studies published from 2011 to 2022 available in PubMed, Web of Science, Embase and Open Grey literature were retrieved by ad hoc prepared search strings. The meta-analyses were conducted for both overall ECC prevalence and experience stratified by country of publication as well as measures of socioeconomic indicators using a random effects model using STATA 18®.

RESULTS

One hundred publications reporting ECC data from 49 countries (published from 2011 to 2022) were included and summarized by meta-analysis. The lowest prevalence was reported in Japan (20.6%) and Greece (19.3%). The global estimated random-effect pooled prevalence of ECC was 49% (95%CI: 0.44-0.55). The random-effect pooled caries prevalence (ECC) was 34% (95%CI: 02.20-0.48) (Central/South America), 36% (95%CI: 0.25-0.47) (Europe), 42% (95%CI: 0.32-0.53) (Africa), 52% (95%CI: 0.45-0.60) (Asia-Oceania), 57% (95%CI: 0.36-0.77) (North America) and 72% (95%CI: 0.58-0.85) (Middle East). When stratified by gross national income (GNI) the ECC prevalence ranged from 30% ($20,000-$39,999) to 57% in countries with the lowest GNI (<$5000). Stratification by inequality index (Gini index) resulted in an ECC prevalence range of 39% (low inequality) to 62% (no inequality), while for life expectancy the ECC prevalence ranged from 28% in countries with the highest life expectancy (< 80 years) to 62% in countries with 71-75 years life expectancy.

DISCUSSION

Within the limitations of this study (lack of certainty about the results as many countries are not represented and lack of uniformity in prevalence and experience data represented), results from 49 different countries reported a wide range of ECC prevalence. These reports indicated persisting high worldwide distribution of the disease. Both ECC prevalence and experience were associated with geographical areas and GNI.

REGISTRATION

PROSPERO: CRD-42,022,290,418.

Passive Smoking and Oral Health of Infants, Preschoolers, and Children: A Systematic Review

INTRODUCTION

Almost half of the world's children experience passive smoking, which is linked to numerous oral health conditions. The aim is to synthesize data on the impact of passive smoking on oral health of infants, preschoolers, and children.

AIMS AND METHODS

A search was conducted across Medline (via EBSCOhost), PubMed, and Scopus up to February 2023. Risk of bias was assessed according to the Newcastle-Ottawa Scale (NOS).

RESULTS

The initial search produced 1221 records and after removal of duplicates, screening by title and abstract, and full-text assessment, 25 studies were eligible for review and data extraction. The majority of studies (94.4%) found a correlation between passive smoking and increased prevalence of dental caries with three studies suggesting a dose-response relationship. Prenatal passive smoking exposure in 81.8% of studies indicated an increased dental caries experience compared to postnatal exposure. Low parental education, socioeconomic status, dietary habits, oral hygiene, and gender affected the level of environmental tobacco smoke (ETS) exposure and dental caries risk.

CONCLUSIONS

The results of this systematic review strongly suggest a significant association between dental caries in the deciduous dentition and passive smoking. Early intervention and education on the effects of passive smoking on infants and children will allow for the improvement in oral health outcomes and reduction in smoking-associated systemic conditions. The results justify all health professionals paying more attention to passive smoking when conducting pediatric patient histories, contributing to improved diagnosis and appropriate treatment planning with more suitable follow-up schedules.

IMPLICATIONS

The evidence from this review that environmental tobacco smoke and passive smoking is a risk factor for oral health conditions, both prenatally and postnatally during early childhood, justifies all health professionals paying more attention to passive smoking when conducting pediatric patient histories. Early intervention and appropriate parental education regarding the effects of secondhand smoke on infants and children will allow for the minimization of dental caries, improvement in oral health outcomes and overall reduction in smoking-associated systemic conditions for the children exposed.

Prenatal tobacco and postbirth second-hand smoke exposure and dental caries in children

OBJECTIVES

Second-hand smoke (SHS) exposure has been identified as a risk factor for several childhood health problems including dental caries. The purpose of this study was to examine the association of postbirth SHS exposure and dental caries and to determine whether the association is independent of prenatal tobacco exposure, sugar consumption and dental utilization.

METHODS

NHANES 2013-2014 and 2015-2016 were used to examine the research question in 1733 children, 4-11 years old with full primary or mixed dentition and serum cotinine levels below 10 ng/mL. Weighted multivariable logistic regression models were developed to examine the independent association between SHS exposure and the prevalence of (i) any dental caries experience and (ii) any decayed teeth.

RESULTS

Children exposed to postbirth SHS differed from children not exposed regarding decayed teeth prevalence in the total sample (OR = 1.80, 95% CI: 1.20, 2.71) and mixed dentition (OR = 1.86, 95% CI: 1.20, 2.90) after confounder adjustment. However, no association was found in the primary dentition or between SHS exposure and total caries experience.

CONCLUSIONS

The findings partially show that postbirth SHS is associated with dental caries in children. However, the inconsistencies in findings across the three samples and between the two outcome measures, dental caries experience and decayed teeth prevalence raise questions regarding the validity of the hypothesis. Further, the findings suggest that postbirth SHS is likely a marker for true causes of dental caries and the association is likely confounded with other factors associated with dental caries.

Correlation Between Maternal Smoking During Pregnancy and Dental Caries in Children: A Systematic Review and Meta-Analysis

Background: Dental caries is a long-standing oral health problem for children all over the world. The available evidence shows that the association between maternal smoking during pregnancy and childhood caries is still controversial. Therefore, the aim of this systematic review and meta-analysis was to determine whether there was a correlation of prenatal smoking and dental caries in children.

Methods: PubMed, EMBASE, Cochrane, Web of Science, and Scopus databases were searched for observational studies assessing the relationship between maternal smoking during the pregnancy and childhood caries. According to the predesigned eligibility criteria and items, studies selection, and data extraction were conducted, respectively. The effect estimates were pooled using a fixed-effect model or a random-effect model. Newcastle-Ottawa Scale (NOS) was adopted to evaluate the methodological quality of the included studies. All analyses were carried out through Stata 12.0 software.

Results: Our systematic review included a total of 11 studies, of which 6 cross-sectional studies and 3 longitudinal studies were included in the final meta-analysis. The pooled estimates indicated maternal smoking during pregnancy was significantly associated with dental caries in children both in cross-sectional studies (OR = 1.57, 95% CI = 1.47–1.67) and longitudinal studies (RR = 1.26, 95% CI = 1.07–1.48). Sensitivity analyses confirmed the overall effect estimates were robust.

Conclusions: There is a significant correlation of maternal smoking during pregnancy and childhood caries. However, the causal relationship between them cannot be determined. More prospective and extensive studies on this theme is needed for verification. Even so, it is necessary for pregnant women and women of reproductive age to quit smoking. Strategies must be developed to raise public awareness about the impact of prenatal smoking on children's oral health.

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

Objective

This review aims to identify variances and research gaps in the early childhood caries (ECC) prevalence within countries and the global community by mapping current evidence.

Materials and methods

We performed a literature search in PubMed/MEDLINE and Web of Science to identify English-language, peer-reviewed epidemiologic studies published from January 1999 to January 2019. Abstracts and full-text articles were dual-screened based on predefined eligibility criteria. We classified outcomes by children's age and countries based on economic status. Ranges of reported caries prevalence and median values by country and age were calculated and evidence-mapped.

Results

Out of 915 studies, 59 studies met the inclusion criteria. The most significant number of reports were from the USA, Brazil, and India. The ranges of prevalence (1-96%) among the studies were large. The calculated median caries prevalence values may better estimate countries' prevalence than the reported ranges. Early childhood caries prevalence's highest median values were found for South Korea studies (54%) for children <3-year-old and from Bosnia (81%) for children 3-6 years old. No apparent difference was found in the prevalence of ECC from developed and developing countries.

Conclusion

This mapping review reflects the ranges and median values of ECC worldwide. Overall, the reported prevalence of ECC in most countries is very high. No apparent difference was found in the prevalence of ECC from developed and developing countries. Reported ranges of ECC, as well as heterogeneity and methodological issues, hamper comparisons across studies globally.

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.

How to cite this article

Abdelrahaman M, Hsu K-L, Melo MA, et al. Mapping Evidence on Early Childhood Caries Prevalence: Complexity of Worldwide Data Reporting. Int J Clin Pediatr Dent 2021;14(1):1-7.

Association between Dental Caries and Passive Smoking and Its Related Factors in Children Aged 3-9 Years Old

Aims

Dental caries is the most common chronic and infectious childhood disease. Several studies have investigated the side effects of cigarette smoke on oral health. Caries appear to be higher in children exposed to environmental cigarette smoke, but this relationship has not yet been established. The purpose of this study was to investigate the relationship between dental caries and passive smoker children aged 3-9 years old.

Materials and methods

This descriptive analytical study was performed on 75 children aged from 3 to 9 years. The study included two groups (first group: control, second group: passive smoker). Demographic data, frequency of toothbrushing and using toothpaste, sugar consumption, and number of dental visits were recorded in a questionnaire. Then, the children were examined, and dmft and DMFT index and plaque index were recorded. Children's saliva was then collected and sent to the laboratory for determination of cotinine levels. Then, the relationship between passive smoker and caries index and other factors were statistically analyzed.

Results

Studying dmft and DMFT, it was found that except for component M (Missing) which was zero in both groups, the other components of these two indices were significantly higher in the group exposed to passive smoker. Plaque index and salivary cotinine level were also significantly different in the two groups and were lower in the control group.

Conclusion

According to the results of this study, children exposed to passive smoker have a higher rate of caries than other children. It seems that it is primarily due to its effect on increasing plaque accumulation and then the effect of passive smoker on the physiological structures of the mouth and so on.

Clinical significance

We can perform preventive care for children if we know that passive smoking may cause more dental caries.

How to cite this article

Mosharrafian S, Lohoni S, Mokhtari S. Association between Dental Caries and Passive Smoking and Its Related Factors in Children Aged 3-9 Years Old. Int J Clin Pediatr Dent 2020;13(6):600-605.

Breastfeeding and early childhood caries. Review of the literature, recommendations, and prevention

CONTEXT

Early childhood caries is a chronic disease that affects a child's general state of health. The question of a link between primary tooth caries and breastfeeding has been addressed for many years, with contradictory results. The concomitant decay of primary teeth, effective establishment, or not, of oral hygiene, and alimentary diversification away from breastfeeding are all confounding factors in this topic. The aim of our study was to analyze the links between breastfeeding and the appearance of caries, as described in the scientific literature and in the recommendations of specialist societies.

METHODS

A review of publications written in English and French was carried out, searching for the terms early childhood caries, decay and breastfeeding, focusing on literature reviews and meta-analyses dating from the past 10 years. The PubMed database of the US National Library of Medicine National Institutes of Health (NBCI) was used. Furthermore, a review of specialist dental and pediatric societies was conducted.

RESULTS

Breastfeeding until the age of 1 year is not associated with an increased risk of dental caries, and may even provide protection compared with feeding with formula milk. By contrast, infants who are breastfed beyond the age of 12 months demonstrate an increased risk of caries. However, the results derive from heterogeneous studies that do not always take into account contradictory factors such as eating habits of the mother or infant (feeding during the night, number of meals per day, eating sweet foods etc.), dental hygiene, or the sociocultural context. Moreover, the most recent recommendations of pediatric and dental societies advise breastfeeding until the age of 2 years, suggesting that this be accompanied by toothbrushing and better nutrition by reducing the frequency and consumption of sugary foods, aimed at helping parents choose prolonged breastfeeding.

CONCLUSION

Extended breastfeeding is a protective factor for childhood caries under 1 year of age. Beyond 1 year, it is difficult to conclude between protection and aggravation of caries because of the multiplicity of confounding factors such as dietary patterns, which vary depending on countries and families, and problems of oral hygiene. In practical terms, when breastfeeding continues beyond 1 year, consultation with a dentist is necessary for examination and preventive advice regarding dietary practices (especially sugar intake), oral hygiene, or supplementary fluoride.

The association between socioeconomic status, psychopathological symptom burden in mothers, and early childhood caries of their children

Objectives

Various maternal mental disorders and socioeconomic status [SES] are discussed as risk factors for early childhood caries [ECC]. In our study, we examined a wide range of symptoms of mental disorders with the aim to identify those maternal psychopathological symptom burdens [PSBs] which show relevant associations with ECC. Our second objective was to investigate how SES affects the associations between PSB and ECC.

Methods

In this study, sixty children with ECC (caries group [CG]) and sixty caries-free children [NON-CG] with their mothers were recruited at two sites in Germany. Children aged three or four years were included in the study. Children’s dental status [dmf-t] and plaque index were recorded, and mothers answered a multidimensional SES index (including education, profession and income) as well as screening questionnaires capturing dental anxiety, depressive disorders, generalized anxiety, somatic symptom burden, eating disorders, traumatic childhood experiences, nicotine dependency and alcohol dependency.

Results

Mothers of the CG reported significantly higher dental anxiety (d_Cohen = 0.66), childhood trauma (d_Cohen = 0.53) and nicotine dependency (d_Cohen = 0.64) than the NON-CG. However, mediator analyses showed that these effects were partly mediated by the SES. Mothers of the CG had a significantly lower SES (d_Cohen = 0.93); with education as strongest predictor of dental status. The groups did not differ significantly in symptoms of depressiveness, subjective somatic symptom burden, alcohol dependency, eating disorders, and generalized anxiety.

Conclusions

Several PSBs are associated with ECC, however the SES as the strongest influencing factor mediates this association. Difficult socioeconomic conditions might predispose for both, ECC and mental illness. Targeted strategies are needed to facilitate the use of preventive measures and dental health services especially in families of lower status. For this purpose, psychosocial risk constellations must be identified. More integrative, multifactorial oriented research is necessary to gain a bio-psycho-social understanding of ECC.

Association between exposure to household smoking and dental caries in preschool children: a cross-sectional study

BACKGROUND

We aimed to examine the association of exposure to environmental tobacco smoke with dental caries among preschool children. Exposure to environmental tobacco smoke was assessed in terms of urinary cotinine concentrations and pack-years of exposure to smoking by parents and other family members at home.

METHODS

This cross-sectional study included 405 preschool children aged 3-6 years from two preschools in Japan in 2006. Information on the smoking habits of family members living with the child was obtained from parent-administered questionnaires. Dental examination was conducted to assess dental caries, that is, decayed and/or filled teeth. Urinary cotinine levels were measured using first-void morning urine samples.

RESULTS

Overall, 31.1% of the children had dental caries, and 29.5% had decayed teeth. Exposure to current maternal and paternal smoking was positively associated with the presence of dental caries after controlling for covariates. More than three pack-years of exposure to maternal smoking and more than five pack-years of exposure to smoking by all family members were significantly associated with the presence of dental caries as compared with no exposure (odds ratio [OR] = 5.55, 95% confidence interval [CI] = 2.17-14.22, P for trend < 0.001 and OR = 2.00, 95% CI = 1.12-3.58, P for trend = 0.004, respectively). These exposure variables were similarly associated with the presence of decayed teeth (OR = 2.92, 95% CI = 1.23-6.96, P for trend = 0.01 and OR = 1.75, 95% CI = 0.96-3.20, P for trend = 0.03, respectively). As compared with lowest tertile of the urinary cotinine level, the highest tertile of the urinary cotinine level was significantly associated with the presence of dental caries as well as decayed teeth; the ORs for the highest vs. lowest tertile of urinary cotinine levels were 3.10 (95% CI = 1.71-5.63, P for trend = 0.012) and 2.02 (95% CI = 1.10-3.70, P for trend = 0.10), respectively.

CONCLUSIONS

These data suggest that exposure to tobacco smoke may have a dose-dependent influence on the development of caries.

Association between passive tobacco exposure and caries in children and adolescents. A systematic review and meta-analysis

To examine the available evidence on the association between exposure to tobacco use in the womb and in infancy and the presence of caries in primary and permanent dentition in children and adolescents.

A systematic review was conducted through searches in 4 data bases (Pubmed, Scopus, Embase and Web of Science), complemented by hand-searching. Of the 559 articles identified, 400 were duplicates. Finally, 28 articles were included in the qualitative review and 21 in the meta-analysis. Their quality was assessed using the Newcastle-Ottawa scale. The quality was medium in 44% of the articles included and high in 56%.

The overall meta-analysis gave a significant odds ratio (OR = 1.53, 95% confidence interval 1.39–1.68, Z test p-value = 0.000) and high heterogeneity (Q = 200.3, p = 0.000; I² = 86.52%). Separate meta-analyses were also performed for three subgroups: exposure in the womb (prenatal) and caries in primary dentition, which resulted in a significant OR = 1.46 with a 95% CI of 1.41–1.52 (Z test p = 0.000), without heterogeneity (Q = 0.91, p = 0.824; I² = 0%); exposure in infancy (postnatal) and caries in primary dentition, with OR = 1.72 (95% CI 1.45–2.05) and high heterogeneity (Q = 76.59, p = 0.00; I² = 83.01%); and postnatal exposure and caries in permanent dentition, with OR = 1.30 (95% CI 1.25–1.34) and no heterogeneity (Q = 4.48, p = 0.880; I² = 0%). In children and adolescents, a significant though moderate association was found between passive tobacco exposure and caries.

[Therapeutic education in pediatric dentistry: analysis of obstacles and levers to the development of programmes in France in 2016]

OBJECTIVE

Over recent years, therapeutic patient education has become part of dental medicine. Management of early childhood caries, known to be a very common chronic disease, has evolved to include an educational dimension. The objective of this study was to identify the levers and barriers to the development of formalized therapeutic education programmes and alternatives.

METHODS

A comprehensive exploratory qualitative study was conducted between November 2015 and June 2016 on a targeted sample of 15 people aware of the problem of TPE in dentistry.

RESULTS

The study showed that TPE training in dentistry is underdeveloped, despite its numerous benefits: change of the healthcare professional's approach, implementation of structured educational programmes, development of research, etc. There are many obstacles to the development of TPE programmes: insufficient resources, rigid legislation or lack of knowledge of TPE practices. The dental profession is an obstacle itself because of its lack of understanding and variable degrees of integration the medical community. There are multiple levers, but the main ones are changing attitudes of the profession and the provision of resources to develop TPE. Although alternatives to TPE programmes exist (accompanying measures, short educational strategies, connected health), they cannot replace TPE.

CONCLUSION

More educational strategies must be developed in the field of dentistry. However, the framework of TPE must be adapted to the profession to ensure good uptake.

Nicotine is a risk factor for dental caries: An in vivo study

Background/purpose

Streptococcus mutans is an important pathogen in the development of dental caries. Many studies have focused on the relationship between nicotine and S. mutans in vitro. The aim of this study was to investigate the effect of nicotine on the growth of S. mutans and its cariogenic potential in vivo.

Materials and methods

Sixteen male Specific-pathogen-free Wistar rats were divided into 2 groups (nicotine-treated and nicotine-untreated group) and infected with S. mutans. The S. mutans suspension was treated with 1 mg/mL nicotine in the nicotine-treated group. The Keyes method was used to evaluate sulcal caries of rats, and dental plaque on molar teeth was observed by scanning electron microscopy (SEM).

Results

Incidence of sulcal caries was higher in nicotine-treated group compared to nicotine-untreated group (42.7 ± 1.7 vs 37.3 ± 4.9, P = 0.009). Severity of caries increased with nicotine treatment. The slightly dentinal caries scores and moderate dentinal caries scores were higher in the presence of nicotine (P < 0.001). Increased number of S. mutans cells attached to dental surface was observed under SEM in the nicotine-treated group.

Conclusion

Nicotine would promote the attachment of S. mutans to dental surface, and further increase the incidence and severity of dental caries. Therefore, nicotine might be a risk factor for smoking-induced caries.

Effects of environmental tobacco smoke on the oral health of preschool children

AIMS

This study investigated the association between the prevalence of oral health problems (caries, gingivitis, mucosal pigmentation and enamel defects in one to 5 year-old children exposed and not exposed to environmental tobacco smoke before and/or after birth. Exposure to environmental tobacco smoke (ETS) in childhood may have significant health effects.

METHODS

A structured questionnaire was used to collect data on a child's current and previous illnesses, oral health behaviours, dietary habits, parental smoking behaviours and parents' dental history. The intraoral examination recorded dental caries (dmfs), enamel defects, gingival health, melanin pigmentation and soft tissue health. Stimulated saliva was collected. Total sIgA levels were quantified using indirect competitive ELISA with a SalimetricsTM kit.

RESULTS

The 44 children (aged 15-69 months) recruited were divided into two groups: ETS and non-ETS (control). There were 22 children in each: 16 who were exposed to ETS during and after gestation were identified as the ETSB subgroup. Participants exposed to ETS were more likely to have had upper respiratory tract and middle ear infections during the neonatal period and had higher mean dmft, mean dmfs, mean percent of surfaces with demarcated opacities and mean GI than the non-ETS participants. The children exposed to ETS before and after birth had the highest occurrence of enamel opacities showed a higher risk for dental caries even though more children in this group used the recommended fluoride toothpaste (1000 ppm fluoride). Mothers who smoked either never breastfed their children or breastfed their children for less than the recommended period of 6 months. Children exposed to ETS were shown to have higher mean total sIgA (μg/ml) than the children in the control group.

CONCLUSIONS

Associations between ETS exposure before and after gestation and oral health, including salivary changes in young children were shown in the present study. Dental health professionals should include a question about household smoking in children's dental histories, which would allow opportunities to discuss the impact of smoking on child oral health. Longitudinal oral health studies should include a history of maternal smoking during pregnancy and afterwards.

Carious lesions of permanent molars and oral health practices of parents and peers in Saudi male adolescents

OBJECTIVES

To assess the association between carious lesions in first and second permanent molars in adolescents and their parents' and peers' oral health practices. Methods: This cross-sectional study of 12-15 year-old male adolescents was conducted in  Dammam, Kingdom of Saudi Arabia, on February 2016. Data collection included dental examination to measure carious lesions and plaque. There was a questionnaire to assess oral health practices such as brushing with fluoridated toothpaste, current daily tobacco use, and daily consumption of sugary food and drinks. Logistic regression models assessed the association between first and second molars carious lesions with adolescents', parents', and peers' oral health practices. Results: Of 302 students, 294 participated. The mother's brushing was significantly associated with a lower odds of carious lesions in the first molar (odds ratio [OR] = 0.17, 95% confidence interval [CI]: 0.04 - 0.77). The mothers' sugary food intake and students' own brushing were significantly associated with carious lesions in the second molar (OR = 1.95 and 0.36, 95% CI: 1.01-9.89 and 0.12-0.89). Friends' intake of sugary drinks had a strong, but non-significant, association with second molar's carious lesions (OR=3.61, 95% CI: 0.35 - 7.44). Conclusion: In Saudi society, mothers have a major influence on their adolescent sons' carious lesions. Adolescents' oral health strategies should involve parents to reduce their risk of caries.

Relationship between dental caries and metabolic syndrome among 13 998 middle-aged urban Chinese

BACKGROUND

The association between dental caries and metabolic syndrome (MetS) is inconsistent. The aim of the present study was to assess the relationship between dental caries and MetS and its components in a middle-aged Chinese population.

METHODS

A cross-sectional analysis was performed of 13 998 participants aged 45-65 years undergoing a health check during 2013-14. An index variable of decayed, missing, and filled teeth (DMFT) was calculated. Logistic regression was used to estimate odds ratios (ORs) and 95 % confidence intervals (CIs) after adjustment for sex, age, education level, dietary habits, alcohol use, smoking, physical activity, and periodontitis.

RESULTS

Of the 13 998 participants, 6164 had dental caries and 7834 did not; 3571 had MetS, whereas 10 427 did not. Participants with severe caries showed a higher prevalence of MetS, abdominal obesity, elevated blood pressure, dyslipidemia, and hyperglycemia than those with mild or no caries (all P < 0.01). Adjusted ORs for MetS for those with two or more dental caries and those with two or more DMFT were 1.12 (95 % CI 1.14-1.74) and 1.09 (95 % CI, 0.89-1.21), respectively (P _trend  < 0.001). Stratified analysis by individual MetS components showed that caries were associated with MetS among subjects with hyperglycemia (OR 1.14 [95%CI, 0.98-1.34]; P < 0.001). However, there was no significant relationship between caries and abdominal obesity, hypertriglyceridemia, low high-density lipoprotein cholesterol, and elevated blood pressure (adjusted ORs [95 % CIs] 0.98 [0.82-1.16], 1.01 [0.85-1.19], 0.84 [0.70-1.00], and 0.96 [0.86-1.13], respectively; all P > 0.05).

CONCLUSIONS

Dental caries were associated with MetS among middle-aged Chinese in the present study.

Bayesian Analysis of the Association between Family-Level Factors and Siblings' Dental Caries

We conducted a Bayesian analysis of the association between family-level socioeconomic status and smoking and the prevalence of dental caries among siblings (children from infant to 14 y) among children living in rural and urban Northern Appalachia using data from the Center for Oral Health Research in Appalachia (COHRA). The observed proportion of siblings sharing caries was significantly different from predicted assuming siblings' caries status was independent. Using a Bayesian hierarchical model, we found the inclusion of a household factor significantly improved the goodness of fit. Other findings showed an inverse association between parental education and siblings' caries and a positive association between households with smokers and siblings' caries. Our study strengthens existing evidence suggesting that increased parental education and decreased parental cigarette smoking are associated with reduced childhood caries in the household. Our results also demonstrate the value of a Bayesian approach, which allows us to include household as a random effect, thereby providing more accurate estimates than obtained using generalized linear mixed models.

Secondhand smoke and incidence of dental caries in deciduous teeth among children in Japan: population based retrospective cohort study

STUDY QUESTION

Does maternal smoking during pregnancy and exposure of infants to tobacco smoke at age 4 months increase the risk of caries in deciduous teeth?

METHODS

Population based retrospective cohort study of 76 920 children born between 2004 and 2010 in Kobe City, Japan who received municipal health check-ups at birth, 4, 9, and 18 months, and 3 years and had information on household smoking status at age 4 months and records of dental examinations at age 18 months and 3 years. Smoking during pregnancy and exposure of infants to secondhand smoke at age 4 months was assessed by standardised parent reported questionnaires. The main outcome measure was the incidence of caries in deciduous teeth, defined as at least one decayed, missing, or filled tooth assessed by qualified dentists without radiographs. Cox regression was used to estimate hazard ratios of exposure to secondhand smoke compared with having no smoker in the family after propensity score adjustment for clinical and lifestyle characteristics.

STUDY ANSWER AND LIMITATIONS

Prevalence of household smoking among the 76 920 children was 55.3% (n=42 525), and 6.8% (n=5268) had evidence of exposure to tobacco smoke. A total of 12 729 incidents of dental caries were observed and most were decayed teeth (3 year follow-up rate 91.9%). The risk of caries at age 3 years was 14.0% (no smoker in family), 20.0% (smoking in household but without evidence of exposure to tobacco smoke), and 27.6% (exposure to tobacco smoke). The propensity score adjusted hazard ratios of the two exposure groups compared with having no smoker in the family were 1.46 (95% confidence interval 1.40 to 1.52) and 2.14 (1.99 to 2.29), respectively. The propensity score adjusted hazard ratio between maternal smoking during pregnancy and having no smoker in the family was 1.10 (0.97 to 1.25).

WHAT THIS STUDY ADDS

Exposure to tobacco smoke at 4 months of age was associated with an approximately twofold increased risk of caries, and the risk of caries was also increased among those exposed to household smoking, by 1.5-fold, whereas the effect of maternal smoking during pregnancy was not statistically significant.

FUNDING, COMPETING INTERESTS, DATA SHARING

This study was supported by a grant in aid for scientific research 26860415. The authors have no competing interests or additional data to share.