Active and passive smoking and tooth loss in Japanese women: baseline data from the osaka maternal and child health study

Association between exposure to secondhand smoking at home and tooth loss in Japan: A cross-sectional analysis of data from the 2016 National Health and Nutrition Survey

INTRODUCTION

Tooth loss affects oral health and physical and social functions. With widespread population aging, its prevalence is increasing. Secondhand smoking is a risk factor for oral diseases; however, in Japan, there are currently no regulations restricting exposure to secondhand smoke at home. This cross-sectional study examined the association between secondhand smoking at home and tooth loss among Japanese adults.

METHODS

The study examined secondary data from the 2016 National Health and Nutrition Survey, Japan. The self-reported responses of 18812 non-smokers aged ≥20 years were analyzed. The association between exposure to secondhand smoke at home and number of teeth was examined through multiple linear regression with multiple imputation. To obtain a more normal distribution, logarithmic transformation was applied to the number of teeth that deviated substantially from a normal distribution. Adjustments were made for sex, age, occupation, household size, dental check-up within the past year, and exposure to secondhand smoke outside the home.

RESULTS

Overall, 8.4% of the respondents were exposed to secondhand smoking at home almost every day; this percentage was larger among younger respondents, who also had more teeth than the older respondents. Although the univariate linear regression did not show a positive association between exposure to secondhand smoke and tooth loss, the multivariate-adjusted analysis revealed that respondents who were exposed to secondhand smoke at home almost every day had fewer teeth (β= -0.04; 95% CI: -0.07 – -0.01).

CONCLUSIONS

The present results suggest that exposure to secondhand smoke at home increases the risk of tooth loss.

Parity and Number of Teeth in Japanese Women: Results from the Japan Nurses' Health Study

Background: Parity is thought to be associated with a decreased number of teeth present in women. However, educational level and social status, which are particularly significant risk factors for loss of teeth, have been heterogeneous in previous observations. This cross-sectional survey aimed to clarify the associations of parity with the risk of having <20 teeth in Japanese female nurses participating in the Japan Nurses' Health Study (JNHS). Methods: In the third follow-up questionnaire of the JNHS, 11,299 women aged 27-82 years participated in this study. The number of participants according to age range was 7,225 (63.9%) aged <50 years and 4,074 (36.1%) aged ≥50 years. Information on parity and risk factors for loss of teeth was collected through a baseline questionnaire and then a follow-up questionnaire. Multivariate logistic regression analysis was used to calculate the adjusted odds ratio (OR) and 95% confidence interval (CI) of having <20 teeth according to parity category. Results: Participants ≥50 years who had experienced three or more deliveries had a significantly higher risk of having <20 teeth than those who had not experienced delivery (OR = 1.59, 95% CI = 1.14-2.20), although this finding was not observed in participants <50 years. In addition to parity, age and current smoking may be independent risk factors for having <20 teeth in Japanese nurses. Conclusions: Higher-parity female nurses ≥50 years may be more likely to lose teeth than those who have not experienced delivery.

Does second-hand smoke associate with tooth loss among older Japanese? JAGES cross-sectional study

OBJECTIVE

Second-hand smoke (SHS) is considered a risk factor for a number of oral diseases. However, its influence on tooth loss, which is the final consequence of periodontal disease and caries, remains unknown. We aimed to evaluate the association between SHS experience and the number of remaining teeth among non-smoking older Japanese individuals.

METHODS

Cross-sectional data from the Japan Gerontological Evaluation Study (JAGES) 2013 were used. From the 27,561 people ≥65 years of age who responded to a self-reported questionnaire (response rate = 71.1%), data of 18,865 respondents who had never smoked were analysed. Multinomial logistic regression with multiple imputations was applied to estimate the odds ratio of the frequency of SHS exposures on the number of remaining teeth.

RESULTS

The prevalence of participants with ≥20 teeth, 10-19 teeth, 5-9 teeth, 1-4 teeth, and no teeth were 53.2%, 20.4%, 9.9%, 6.6%, and 9.9%, respectively. The proportion of participants with SHS was 37.5%. After adjusting for sex, the SHS experience tended to be associated with a lower risk of having the fewer number of remaining teeth (P < 0.05). However, after being adjusted for age and sex, participants with SHS exposure at "a few times a week" and "almost every day" were significantly associated with the fewer number of teeth. After adding all other covariates, compared to the participants without any exposure to SHS, the odds ratio for having no teeth rather than having ≥20 teeth among the participants with daily exposure to SHS was 1.35 (P < 0.01).

CONCLUSION

Daily second-hand smoke was significantly associated with fewer remaining teeth based on the self-reported survey among older Japanese people.

Effect of smoking cessation on tooth loss: a systematic review with meta-analysis

BACKGROUND

Smoking is a major risk factor for periodontitis and tooth loss. Smoking cessation has a positive impact in periodontal treatment. However, so far, no systematic review has evaluated the effect of smoking cessation on tooth loss. Therefore, this review aimed to evaluate if smoking cessation reduces the risk of tooth loss.

METHODS

Observational (cross-sectional and longitudinal) studies that investigated the association between smoking cessation and tooth loss were included. MEDLINE, EMBASE and LILACS databases were searched for articles published up to November 2018. Pooled results for subgroups of current and former smokers were compared in meta-analysis. Meta-regression was used to test the influence of smoking status on estimates and explore the heterogeneity.

RESULTS

Of 230 potentially relevant publications, 21 studies were included in the qualitative review and 12 in the quantitative analysis. Meta-analysis of cross-sectional studies did not show any differences between former and current smokers in the chance of losing 1 or more teeth (OR = 1.00; 95% CI = 0.80 to 1.24, I² = 80%), losing more than 8 teeth (OR = 1.02; 95% CI = 0.78 to 1.32, I² = 0%) or being edentulous (OR = 1.37; 95% CI = 0.94 to 1.99, I² = 98%). Meta-analysis from longitudinal studies showed that, when compared to never smokers, former smokers presented no increased risk of tooth loss (RR = 1.15; 95% CI = 0.98 to 1.35, I² = 76%), while current smokers presented an increased risk of tooth loss (RR = 2.60; 95% CI = 2.29 to 2.96, I² = 61%). Meta-regression showed that, among former smokers, the time of cessation was the variable that better explained heterogeneity (approximately 60%).

CONCLUSIONS

Risk for tooth loss in former smokers is comparable to that of never smokers. Moreover, former smokers have a reduced risk of tooth loss, when compared to current smokers.

Systematic Review and Meta-analysis of the Association Between Exposure to Environmental Tobacco Smoke and Periodontitis Endpoints Among Nonsmokers

OBJECTIVE

A systematic review was conducted to summarize the epidemiological evidence on environmental tobacco smoke (ETS) exposure and prevalent periodontitis endpoints among nonsmokers.

METHODS

We searched PubMed, EMBASE, Web of Science, Pro-Quest dissertations, and conference proceedings of a dental research association. We included studies from which prevalence odds ratios (POR) could be extracted for periodontitis determined by examiner measurements of clinical attachment level (CAL) and/or probing pocket depth (PD) or self-report of missing teeth. Studies determined ETS exposure by self-report or biomarker (cotinine) levels.

RESULTS

For studies reporting CAL and/or PD (n = 6), associations were stronger with cotinine-measured exposure (n = 3; random effects POR [95% prediction interval] = 1.63 (0.90, 2.96)) than self-reported exposure (n = 3; random effects POR = 1.15 (0.68, 1.96)). There was no meaningful difference in summary estimate for studies reporting CAL and/or PD endpoint (n = 6; random effects POR = 1.34 (0.93, 1.94)) as opposed to tooth loss (n = 2; random effects POR = 1.33 (0.52, 3.40)).

CONCLUSIONS

There appears to be a positive association between exposure to ETS and prevalent periodontitis endpoints among nonsmokers, the magnitude of which depended mostly on the method of ETS assessment.

IMPLICATIONS

The notoriety of ETS is often discussed in terms of its associations with cancer, chronic conditions like cardiovascular diseases, and respiratory illnesses in children. However, very little attention is paid to its association with oral diseases, especially periodontitis. Periodontitis affects a large proportion of the population and is a major cause of tooth loss. This study summarized the epidemiologic association between exposure to ETS and periodontitis among nonsmokers. Although the findings are consistent with a positive association, methodological weaknesses relating to study design, assessment of ETS, periodontitis, and adjustment covariates were highlighted and recommendations for improvement in future studies provided.

Epidemiology and risk factors of tooth loss among Iranian adults: findings from a large community-based study

Objectives. To investigate the prevalence of tooth loss and different prosthetic rehabilitations among Iranian adults, as well as the potential determinants of tooth loss. Methods. In a cross-sectional community-based study conducted among 8094 Iranian adults living in Isfahan province, a self-administered questionnaire was used to assess epidemiologic features of tooth loss. Results. Thirty-two percent of subjects had all their teeth, 58.6% had lost less than 6, and 7.2% of participants had lost more than 6 teeth. One hundred and sixty-nine individuals (2.2%) were edentulous. Among participants, 2.3% had single jaw removable partial denture, 3.6% had complete removable denture in both jaws, and 4.6% had fixed prosthesis. Others reported no prosthetic rehabilitation (89.5%). In the age subgroup analysis (≤35 and >35 years old) tooth loss was more prevalent among men than women (OR = 2.8 and 1.9, resp., P < 0.01). Also, in both age groups, current and former smokers had higher levels of tooth loss than nonsmokers (P < 0.001 and P < 0.05, resp.). In addition, tooth loss was positively related to metabolic abnormality for age group >35 years (adjusted OR = 1.29, P < 0.01). Conclusions. Tooth loss is highly prevalent in Iranian adult population. Community programs promoting oral health for prevention of tooth loss should be considered taking into account its major determinants including lower educational level, male gender, smoking, and metabolic abnormality.

Smoking increases risk of tooth loss: A meta-analysis of the literature

AIM: To quantitatively evaluate the impact of smoking on tooth loss.

METHODS: We performed a PubMed search to identify published articles that investigated the risk of tooth loss by smoking, from which RRs and their variance with characteristics of each study were extracted. The random-effects models were used to derive a pooled effect across studies. Potential sources of heterogeneity on the characteristics of the study and their influence on the pooled effect size were investigated using meta-regression models.

RESULTS: We identified 24 studies containing a total of 95973 participants for analysis. The pooled RR of ever-smokers compared with never- smokers was 1.73 (95%CI: 1.60-1.86, P < 0.001). In meta-regression analysis, only the mean age of participants alone was identified as a statistically significant source of heterogeneity. The effect of smoking on tooth loss was stronger when the mean age of study participants was higher, indicating possible enhancement of tooth loss due to aging by smoking. RR was significantly lower in former smokers (1.49, 95%CI: 1.32-1.69, P < 0.001) than in current smokers (2.10, 95%CI: 1.87-2.35, P < 0.001), indicating the substantial benefit of smoking cessation for reducing the risk of tooth loss.

CONCLUSION: Smoking is an independent risk factor for tooth loss regardless of many other confounders. Smoking cessation may attenuate this effect.

Change in bone mineral density and tooth loss in Japanese community-dwelling postmenopausal women: a 5-year cohort study

The aim of this longitudinal study was to investigate the association between the change in bone mineral density (BMD) and tooth loss in Japanese community-dwelling postmenopausal women. The subjects were 404 women. At baseline (2005) and follow-up (2010), BMDs of the lumbar spine and right femoral neck were measured using dual-energy X-ray absorptiometry (QDR4500a) and participants were classified by tertiles of the annual percentage change in BMD. The number of teeth was counted at the baseline and follow-up to calculate the number of lost teeth over 5 years. Poisson regression analysis was conducted with tertiles of the changes in BMDs of the lumbar spine and femoral neck as the main exposures to estimate their influence on the number of lost teeth. Participants in the tertile with a greater decrease in BMD at each skeletal site (lumbar spine and femoral neck, respectively) had a larger number of lost teeth, controlling for possible confounders. The adjusted relative risks (95% confidence interval) for the mean number of lost teeth in the first, second, and third tertiles were 1.00, 1.15 (0.91-1.45), and 1.38 (1.11-1.72) for the lumbar spine and 1.00, 1.17 (0.93-1.47), and 1.27 (1.01-1.59) for the femoral neck, respectively. In conclusion, a significant relationship exists between a change in BMD and the number of lost teeth during 5-year study period in Japanese community-dwelling postmenopausal women.

Causal assessment of smoking and tooth loss: a systematic review of observational studies

BACKGROUND

Tooth loss impairs oral function. The aim of the present review was to evaluate the causal association between smoking and tooth loss on the basis of high-quality studies.

METHODS

Relevant literature was searched and screened, and the methodological quality was assessed. Information on the strength of the association between smoking and tooth loss, the dose-response relationship and natural experimental data was collected and evaluated with respect to consistency and study design.

RESULTS

Our literature search yielded 496 citations, and 6 cross-sectional and 2 cohort high-quality studies examining 58,755 subjects in four countries. All studies reported significant associations, although the strength of the association was usually moderate. Four studies reported dose-response relationships between exposure to smoking and the risk of developing tooth loss. A decrease in the risk of tooth loss for former smokers was evident in six studies. Interpretation of evidence for each element was consistent, despite some shortcomings regarding study type and population.

CONCLUSIONS

Based on the consistent evidence found with the existing biological plausibility, a causal association between smoking and tooth loss is highly likely. Further studies using a cohort design and different populations are necessary to confirm this association.

Clinical and community risk models of incident tooth loss in postmenopausal women from the Buffalo Osteo Perio Study

 

OBJECTIVE

While risk factors for tooth loss in adults have been identified, limited studies describing factors associated with incident tooth loss in postmenopausal women exist. This study assessed both clinical and non-clinical risk factors for incident tooth loss.

METHODS

Postmenopausal women (N = 1341) were recruited between 1997 and 2000 from 1847 eligible Observational Study participants of the Buffalo, NY center of the Women's Health Initiative who had complete dental examinations to assess alveolar bone height, soft tissue attachment and general oral health, and completed questionnaires concerning demographics, general health, lifestyle and oral health (72.6% participation rate). Five years later (2002-2005), 1021 women (76.1%) repeated these examinations and questionnaires. Incident tooth loss was determined by oral examination.

RESULTS

After an average 5.1 years of follow-up (SD, 0.38), a total of 323 teeth were lost in 293 women, resulting in 28.7% of women with incident loss of at least one tooth. In multivariable models, diabetes history, gum disease history, smoking, previous tooth loss, BMI and plaque index, baseline clinical measures including alveolar crestal height (ACH) (OR = 1.22 per mm loss, 95% CI 1.11, 1.35), clinical attachment loss (CAL) (OR = 1.13 per mm loss, 95% CI 1.05, 1.23), and pocket depth (PD) (OR = 1.26 per mm loss, 95% CI 1.13, 1.41) were significant risk factors of incident tooth loss. In a community model that included no clinical measures, diabetes history (OR = 2.45, 95% CI 1.26, 4.77), prior gum disease (OR = 1.97, 95% CI 1.43, 2.70), ever smoking (OR = 1.42, 95% CI 1.06, 1.89), number of teeth lost at baseline (OR = 1.05 per tooth, 95% CI 1.02, 1.08), and BMI (OR = 1.15 per 5 km/m(2) increase, 95% CI 1.01, 1.33) were associated with an increased risk of incident tooth loss.

CONCLUSIONS

Clinical and questionnaire-based models were found to provide similar risk estimates for incident tooth loss in postmenopausal women. These models identified high-risk postmenopausal women where preventive strategies may be targeted.

Nutritional adequacy of three dietary patterns defined by cluster analysis in 997 pregnant Japanese women: the Osaka Maternal and Child Health Study

OBJECTIVE

To examine the adequacy and inadequacy of dietary patterns in pregnant women for which information is absolutely lacking.

DESIGN

Diet was assessed by a validated, self-administered diet history questionnaire (DHQ). Dietary patterns were extracted from the intake of thirty-three food groups (g/4184 kJ (1000 kcal)), which were summarized from 147 foods assessed with the DHQ, by cluster analysis. Nutritional inadequacy for selected twenty nutrients in each dietary pattern was examined using the reference values given in the Dietary Reference Intakes (DRI) for Japanese as the temporal gold standard.

SETTING

Japan.

SUBJECTS

Nine hundred and ninety-seven pregnant Japanese women aged 18-43 years.

RESULTS

The three dietary patterns identified were labelled as 'meat and eggs' (n 423), 'wheat products' (n 371) and 'rice, fish and vegetables' (n 203). The 'rice, fish and vegetables' pattern characterized by high intake of rice, vegetables, potatoes, pulses, fruits, seaweed, fish and miso soup showed significantly the lowest prevalence of inadequate intake for fifteen nutrients and significantly the highest prevalence of inadequate sodium intake. In contrast, the 'wheat products' pattern characterized by high intake of bread, noodles, confectioneries and soft drinks showed the highest prevalence of inadequate intake for fourteen nutrients. The median number of nutrients not meeting the DRI as a marker of overall nutritional inadequacy was eight in the 'rice, fish and vegetables' pattern. It was significantly lower at ten in the 'meat and eggs' and eleven in the 'wheat products' patterns (P<0.001).

CONCLUSIONS

In pregnant Japanese women, the dietary pattern high in rice, fish, vegetables, fruit and some others showed a better profile of nutritional adequacy except for sodium.

Cigarette smoking and tooth loss experience among young adults: a national record linkage study

Background

Various factors affect tooth loss in older age including cigarette smoking; however, evidence regarding the association between smoking and tooth loss during young adulthood is limited. The present study examined the association between cigarette smoking and tooth loss experience among adults aged 20–39 years using linked data from two national databases in Japan.

Methods

Two databases of the National Nutrition Survey (NNS) and the Survey of Dental Diseases (SDD), which were conducted in 1999, were obtained from the Ministry of Health, Labor and Welfare with permission for analytical use. In the NNS, participants received physical examinations and were interviewed regarding dietary intake and health practices including cigarette smoking, whereas in the SDD, participants were asked about their frequency of daily brushing, and received oral examinations by certified dentists. Among 6,805 records electronically linked via household identification code, 1314 records of individuals aged 20 to 39 years were analyzed. The prevalence of 1+ tooth loss was compared among non-, former, and current smokers. Multiple logistic regression models were constructed including confounders: frequency of tooth brushing, body mass index, alcohol consumption, and intake of vitamins C and E.

Results

Smoking rates differed greatly in men (53.3%) and women (15.5%). The overall prevalence of tooth loss was 31.4% (31.8% men and 31.1% women). Tooth loss occurred more frequently among current smokers (40.6%) than former (23.1%) and non-smokers (27.9%). Current smoking showed a significant association with 1+ tooth loss in men (adjusted OR = 2.21 [1.40–3.50], P = 0.0007) and women (1.70 [1.13–2.55], P = 0.0111). A significant positive exposure-related relationship between cigarette smoking status and tooth loss was observed (P for trend < 0.0001 and 0.0004 in men and women, respectively). Current smoking was also associated with the prevalence of decayed teeth (1.67 [1.28–2.20], P = 0.0002).

Conclusion

An association between cigarette smoking and tooth loss was evident among young adults throughout Japan. Due to limitations of the available variables in the present databases, further studies including caries experience and its confounders should be conducted to examine whether smoking is a true risk of premature tooth loss in young adults.

Relationship between smoking status and tooth loss: findings from national databases in Japan

Background

A causal association between cigarette smoking and periodontal disease has been established. The present study examined the association between smoking and tooth loss using national databases in Japan.

Methods

Records of the Survey of Dental Diseases and the National Nutrition Survey in 1999 were linked electronically using common identification. Records of 3,999 subjects aged older than 40 years were analyzed using logistic regression models, controlling for confounding factors, such as age, frequency of tooth brushing, body mass index, alcohol consumption, and intakes of vitamin C and E.

Results

Prevalence of tooth loss in terms of having less than 19 existing teeth was 37.3% overall. Smoking rates differed in males (45.6%) and females (7.8%). The prevalence of tooth loss in nonsmokers, former, and current smokers was 28.5%, 38.6%, and 36.9% in males, and 38.6%, 34.3% and 38.9% in females, respectively. Adjusted means of existing teeth controlling for confounders by smoking status were 21.5, 19.7 and 18.2 in males and 19.0, 19.2 and 16.4 in females, respectively. The association of tooth loss was non-significant in former smokers but significant in current smokers: adjusted odds ratios (95% confidence intervals) relative to nonsmokers in males and females were 1.29 (0.92-1.80) and 0.86 (0.46, 1.60) for former smokers and 2.22 (1.61-3.06) and 2.14 (1.45-3.15) for current smokers, respectively. A dose-response relationship between lifetime exposure and tooth loss was seen (P for trend <0.0001).

Conclusion

The findings of this cross-sectional study of a nationwide population of Japanese indicated an association between smoking and tooth loss.

Interaction of obesity and skeletal bone mineral density in tooth retention in Japanese postmenopausal women

OBJECTIVE

To investigate whether being overweight is associated with increased or decreased risk of tooth loss in Japanese postmenopausal women.

DESIGN

The number of remaining teeth (total, anterior, and posterior teeth), mandibular bone height, and mandibular cortical mass were evaluated on the dental panoramic radiographs of 450 Japanese postmenopausal women. The bone mineral densities (BMDs) at the lumbar spine and femoral neck were measured by dual-energy x-ray absorptiometry. These measurements were compared among participants in three body mass index (BMI) categories (underweight, normal BMI, and overweight).

RESULTS

Analysis of covariance adjusted for confounding variables revealed that participants who were overweight had a significantly lower number of total (P = 0.019) and anterior (P = 0.012) remaining teeth than did those with normal BMI, although the former had significantly higher skeletal BMD values than the latter. No significant difference was observed in mandibular bone height between the overweight participants and those with normal BMI. There were no significant differences in the number of remaining teeth between the under- and overweight participants. Overweight participants had significantly higher skeletal BMDs (P < 0.001) and tended to have larger mandibular cortical masses than those who were underweight.

CONCLUSIONS

Despite their higher skeletal BMD, postmenopausal women who are overweight may have an increased risk of tooth loss, especially of the anterior teeth, compared with women who have normal BMI. This risk appears to be similar to that for underweight women.

Association of total tooth loss with smoking, drinking alcohol and nutrition in elderly Japanese: analysis of national database

OBJECTIVE

Various factors may be associated with edentulism in elderly people. Association of total tooth loss with smoking, alcohol intake and nutrition in non-institutionalised elderly Japanese was assessed utilising national database.

MATERIALS AND METHODS

Records of independent surveys, the Survey of Dental Diseases (SDD) and the National Nutrition Survey (NNS) in 1999 were electronically linked using the household identification number.

RESULTS

Among the records of 6903 subjects in the SDD and 12 763 subjects in the NNS, 6805 records were successfully linked. Overall, prevalence of total tooth loss in adults was very similar in males and females at approximately 7.0%, and the smoking rate was 47.6% and 9.9% respectively. Total tooth loss was a rare phenomenon (<2%) in age groups of <60 years. According to the multiple logistic regression analysis involving 2200 subjects aged 60 years or older, significant variables were age, current smokers and vitamin C intake in males, and age and current smokers in females. The variable for current drinkers was significant in females but the odds ratio was <1.0. No significant relationship was detected with respect to former smokers and drinkers, body mass index, vitamin E intake and blood glucose level.

CONCLUSIONS

Current smoking was associated with total tooth loss, although smoking rate was low in females. Gender difference in the association was suggestive with respect to drinking alcohol and vitamin C intake.

Dioxins in human milk and smoking of mothers

BACKGROUND

The relation between the levels of dioxins in human breast milk and the smoking habits of the mothers is controversial. To clarify this relationship, we analyzed data from the human milk survey in Japan.

METHODS

The human milk survey has been conducted in Japan since 1997. Healthy pregnant women aged 20-39 years were recruited and 50 ml of breast milk was collected from them at 30 days after delivery. PCDDs, PCDFs, and dioxin-like PCBs were measured by using GC/MS. The smoking habits of the mothers were established by interviewing them soon after delivery and were classified into four categories: current smokers, ever smokers who quit smoking at the pregnancy, ever smokers who quit smoking before the pregnancy, and never smokers. The levels of dioxins in breast milk were compared in the four categories of smoking among 853 primiparas. In addition, we analyzed the association between dioxin levels and passive smoking among never smokers. The geometric means of the dioxin concentrations were calculated in order to compare the differences between dioxins.

RESULTS

The geometric means of dioxin-like PCBs in milk of never smokers was the highest (9.2 pg TEQ/g fat); followed by ever smokers who quit smoking before the pregnancy, ever smokers who quit smoking at the pregnancy, and current smokers (7.5, 7.2, and 6.6 pg TEQ/g fat, respectively). The differences between these levels were statistically significant (ANOVA, p<0.001). No significant difference was observed between the level of dioxins in milk from never smokers subjected to passive smoking status and those who had not experienced passive smoking.

CONCLUSION

The levels of dioxin-like PCBs in human milk were negatively related to the smoking habits of mothers.

Association of Smoking in Household and Dental Caries in Japan

OBJECTIVES

The study investigated the relationship between smoking in the household and dental caries in Japanese children using nationally representative cross-sectional data.

METHODS

This study included 925 children aged 1-14 years. A child was considered to have decayed and/or filled teeth if a dentist diagnosed these conditions in deciduous or permanent teeth. Smoking in the household was defined as positive if someone in the household reported smoking cigarettes.

RESULTS

No statistically significant relationship was observed between household smoking and caries experience. However, smoking in the household was independently associated with an increased prevalence of decayed teeth. The adjusted mean of filled teeth among children exposed to household smoking was higher than that among non-exposed children.

CONCLUSIONS

The results of the study failed to substantiate a positive association between passive smoking and caries experience in Japanese children.

Gender differences in tooth loss among Chilean adolescents: socio-economic and behavioral correlates

OBJECTIVE

To investigate gender differences in tooth loss among Chilean adolescents and its association with selected socio-economic indicators and oral-health-related behaviors.

MATERIAL AND METHODS

Data on 9,163 Chilean adolescents obtained using multistage random cluster procedures. Clinical recordings included information on missing teeth and the participants provided information on socio-demographic factors and oral-related behaviors. Two eruption-time-adjusted logistic regression analyses were used to investigate the associations between gender, tooth loss and socio-economic position/oral-health-related behaviors.

RESULTS

The association between gender and tooth loss remained after adjusting for age, eruption times in both the socio-economic position regression model and the oral-health-related behaviors model. Tooth loss followed social gradients for the variables paternal income and achieved parental education, with students reporting a paternal income < 100,000 US dollars (OR = 2.0), and having a father (OR = 1.8) and a mother (OR = 2.0) who achieved only primary school education being more likely to experience tooth loss. The adjusted regression model for behavioral indicators revealed that students who reported brushing their teeth once a day (OR = 1.6) were more likely to have experienced tooth loss than those who reported more frequent toothbrushing. Students who visited a dentist rarely (OR = 0.8) or never (OR = 0.5) were less likely to have lost first molars and/or incisors.

CONCLUSIONS

The results demonstrate that gender differences in tooth loss among young Chileans are related to socio-economic position; and selected oral-health-related behaviors after adjusting for eruption time variation.