Association between breastfeeding and periodontitis in Korean women using Korea National Health and Nutrition Examination Survey (KNHANES): a cross-sectional study.

OBJECTIVES: The effect of breastfeeding on periodontal disease in women remains unclear. This cross-sectional study used data from the Korean National Health and Nutrition Examination Survey to explore the association between breastfeeding and periodontitis in Korean women using data from the Korean National Health and Nutrition Examination Survey (KNHANES VII). MATERIALS AND METHODS: Cross-sectional data was analyzed from the KNHANES 2016-2018. The study population included 5,587 parous women aged ≥ 30 years. The outcome variable was the presence or absence of periodontitis. The explanatory variable, period of breastfeeding, was defined as "none", "1-11 months", and "more than 12 months". Confounder variables (socio-educational, personal healthcare practice, and systemic medical characteristics) were adjusted for in the logistic regression analysis. RESULTS: Approximately 60% of the participants breastfed for ≥ 12 months. In all statistical models, the prevalence of periodontitis was approximately 60% greater in women that did not breastfeed compared to women that had breastfed for 12 months or longer. When adjusted for age, statistical significance was only present in the 50-59 years age group (adjusted odds ratio [aOR], 1.678; 95% confidence interval [CIs], 1.046-2.691). CONCLUSION: Our study shows that women that breastfed for a relatively long duration had a lower risk of periodontitis. Therefore, breastfeeding may be beneficial for women's periodontal health. These results are expected to be helpful in oral health education for pregnant women.

The use of interdental cleaning devices and periodontal disease contingent on the number of remaining teeth in Korean adults.

This study aimed to investigate the effect of interdental brushes and dental floss on the prevention of periodontitis in participants with ≥ 20 or < 20 remaining teeth by using the Korea National Health and Nutrition Examination Survey 2016-2018. Data from 11,614 participants were analysed using multivariate logistic regression after adjusting for sociodemographic factors (age and sex), socioeconomic factors (level of education and individual income), oral health-related variables (daily toothbrushing), and systemic health-related variables (smoking, diabetes, and obesity). The adjusted odds ratio (AOR) showed statistically significant results for both floss (AOR, 1.41; 95% confidence interval (CI) 1.22-1.64) and interdental brushes (AOR, 1.16; 95% CI 1.01-1.34). However, no significant difference was found in the subjects with fewer than 20 teeth. The subgroup analysis showed that interdental brushes had a significant preventive effect on women who had more than 20 teeth. Among participants with fewer than 20 teeth, interdental brush users had more periodontitis in men. Regarding those with more than 20 teeth, health inequality was alleviated when floss and interdental brushes were used. The bottom line is that the effect of preventing periodontitis in interdental brushes and dental floss was more evident in participants with ≥ 20 remaining teeth rather than in participants with < 20 remaining teeth.

Lactobacillus reuteri AN417 cell-free culture supernatant as a novel antibacterial agent targeting oral pathogenic bacteria.

Lactobacillus reuteri AN417 is a newly characterized probiotic strain. The activity of AN417 against oral pathogenic bacteria is unknown. We investigated the antibacterial activity of cell-free L. reuteri AN417 culture supernatant (LRS) against three oral pathogens: Porphyromonas gingivalis, Fusobacterium nucleatum, and Streptococcus mutans. P. gingivalis and F. nucleatum have been implicated in periodontal disease, whereas S. mutans causes dental caries. Exposing these oral pathogenic bacteria to LRS significantly reduced their growth rates, intracellular ATP levels, cell viability, and time-to-kill. The minimal inhibitory volume of LRS was 10% (v/v) against P. gingivalis, 20% (v/v) for F. nucleatum, and 30% (v/v) for S. mutans. LRS significantly reduced the integrity of biofilms and significantly suppressed the expression of various genes involved in P. gingivalis biofilm formation. The L. reuteri AN417 genome lacked genes encoding reuterin, reuteran, and reutericyclin, which are major antibacterial compounds produced in L. reuteri strains. LRS treated with lipase and α-amylase displayed decreased antibacterial activity against oral pathogens. These data suggest that the antibacterial substances in LRS are carbohydrates and/or fatty acid metabolites. Our results demonstrate that LRS has antimicrobial activity against dental pathogenic bacteria, highlighting its potential utility for the prevention and treatment of P. gingivalis periodontal disease.

The association between periodontitis and dyslipidemia according to smoking and harmful alcohol use in a representative sample of Korean adults.

OBJECTIVES: The aim of this study was to examine whether dyslipidemia is associated with periodontitis according to age, sex, smoking, and harmful alcohol use in a representative sample of Korean adults who participated in the Sixth Korea National Health and Nutrition Examination Survey (KNHANES VI-3). MATERIALS AND METHODS: We examined 3987 subjects aged 19 to 79 years who participated in the KNHANES VI-3. Dyslipidemia was defined according to the definition proposed by the Korean Society of Lipidology and Atherosclerosis. The periodontal status of the patients was assessed using the community periodontal index. Multivariate logistic regression analysis was carried out and adjusted for sociodemographic variables, oral and general health behaviors, and oral health status. All analyses considered a complex sampling design, and multivariate analysis was performed in the age, sex, smoking, and harmful alcohol use subgroups. RESULTS: Multivariate logistic regression analysis revealed significant associations between periodontitis and dyslipidemia including hypertriglyceridemia and hypo-high-density lipoprotein (HDL) cholesterolemia. In the subgroup analysis, periodontitis was significantly associated with hypo-HDL cholesterolemia in subjects older than 40 years, males, heavy smokers, and hazardous and harmful alcohol users. Moreover, periodontitis was significantly associated with hypercholesterolemia in hazardous and harmful alcohol users. CONCLUSIONS: The prevalence of periodontitis (CPI 3, 20.7%; CPI 4, 9.0%) was 29.7% in Korea. Hyper-TG and hypo-HDL-C were associated with periodontitis in all subjects. In the subgroup analysis, the association of periodontitis with hyper-TC and pre-hyper-TC was further confirmed in harmful alcohol users and males, respectively. CLINICAL RELEVANCE: This study reaffirmed that periodontitis is associated with dyslipidemia, especially with hyper-TG and hypo-HDL-C. As the association of periodontitis with hypo-HDL-C, hyper-TC, and pre-hyper-TC was found differently in subgroups according to age, gender, smoking, and alcohol drinking, researchers need to consider effect modifiers in further studies on the association between periodontitis and dyslipidemia.

Association between regular walking and periodontitis according to socioeconomic status: a cross-sectional study.

Physical activity reduces the risk and mortality risk of inflammatory diseases. This study aimed to examine the relationship between regular walking and periodontitis in a Korean representative sample of adults according to socioeconomic status. Data acquired by the Sixth Korea National Health and Nutrition Examination Survey in 2014 and 2015 were used. The survey was completed by 11,921 (5,175 males; 6,746 females) participants (≥19 years). Individuals without values on periodontitis were excluded, and 9,728 participants remained. Multivariable logistic regression analysis was done using socio-demographic characteristics (age, gender, income, education), oral health-related variables (flossing, interdental brushing, community periodontal index), oral and general health status and behaviour (smoking, diabetes mellitus), and regular walking. In all models, subjects who walked regularly had significantly lower risks of periodontitis. After adjusting for age, gender, income, education, smoking, diabetes mellitus, flossing, and interdental brushing, the odds ratio for periodontitis in subjects who walked regularly was 0.793 (95% Confidence interval: 0.700-0.898). Non-regular walking groups showed similar social gradients. Risk of low socioeconomic status was not significant in the regular walking group after adjusting for age, gender, income, and education. This study found that regular walking is associated to lower prevalence of periodontitis and can attenuate the relationship between periodontitis and low socioeconomic status.

Association of Periodontitis with the Concentration Levels of Germanium and Tin in Hair.

The purpose of this study was to investigate whether or not the concentration levels of certain kinds of trace elements in hair are associated with periodontitis. We studied a total of 109 participants, which are composed of 25 participants with periodontitis and 84 participants without periodontitis. Periodontal conditions were assessed by measuring the periodontal clinical attachment loss and pocket depth, which were determined at six sites of all teeth. Periodontitis was defined according to the criteria of periodontitis proposed by CDC-AAP. The hair samples were washed with acetone, water, and extran (1%v/v), and then aliquots of hair samples were wet-ashed. This sample solution was analyzed by Perkin-Elmer Mass Spectrometer. The odds ratios and 95% confidence intervals of the concentration levels of trace elements for periodontitis were calculated by multivariate logistic regression analysis. After adjusting all confounders, it was found that the higher concentration level of germanium in hair was significantly and positively associated with periodontitis (odds ratio [OR] 7.12; 95% confidential interval [CI] 2.03-25.00). The higher concentration level of tin in hair was significantly and negatively associated with periodontitis (OR 0.27; 95% CI 0.08-0.94). It was concluded that there was a significant relationship between periodontitis and the concentration level of germanium and tin in hair.

Association between age at asthma diagnosis and tooth loss.

OBJECTIVES: This study aimed to investigate the association between age at asthma diagnosis and tooth loss due to caries using data obtained from the Korean National Health and Nutrition Examination Survey. MATERIALS AND METHODS: A complex sample multivariable linear regression was used, and the results were analysed. Age at diagnosis and the number of teeth lost were set as independent and dependent variables, respectively. Among the total 65,973 subjects, 10,056 aged <12 years and 11,714 with missing values in dependent and independent variables were excluded. Asthmatic subjects were divided into the following age groups based on the age at diagnosis: 0-6 years, 7-12 years, 13-18 years, 19-28 years, and 29-64 years. In each analysis, the calibration was performed by adding covariates to each model. RESULTS: Compared with the no asthma group (ß = 0), the values of ß in asthmatic subjects belonging to the age groups 0-6 years (ß = 0.794, 0.521, 0.560) and 7-12 years (ß = 0.527, 0.407, 0.437) were high in all models. CONCLUSIONS: Our findings revealed significant increase in tooth loss due to caries after early asthma diagnosis at 0-6 years (ß = 0.560, p < .001) and 7-12 years (ß = 0.437, p < .001). Clinicians need to shift their perception of dental risks in young asthmatic patients and provide active oral health care to them.

Is yogurt intake associated with periodontitis due to calcium?

The purpose of this study is to determine whether the lower intakes of yogurt, milk, and calcium are associated with periodontitis in a nationally representative sample of Korean adults. This study comprised 6,150 adults 19 or more years old who took both periodontal examination and nutrition survey. The frequency of yogurt and milk intake was examined with a food frequency questionnaire. The amount of calcium intake was calculated with dietary intakes data gained from complete one-day 24-hour recall interviews. Periodontitis was assessed using the Community Periodontal Index (CPI). Multivariate logistic regression analyses were performed for the whole sample and subgroups with the strata of age, gender, or smoking, in a complex sampling design. Less intake of yogurt was significantly associated with periodontitis (odds ratio [OR] 0.82, 95% confidential interval [CI] 0.70-0.97), but neither less intake of milk (OR 1.04, 95% CI 0.89-1.20) nor lower intake of calcium (OR 1.04, 95% CI 0.89-1.21) was significantly associated with periodontitis. In the subgroup analysis, no difference in the association of yogurt intake with periodontitis was found according to the strata of age, gender, and smoking. In conclusion, periodonitis was significantly associated with the less intake of yogurt among the Korean adults, but the calcium contained in yogurt is not likely to cause it.

Association of Some Vitamins and Minerals with Periodontitis in a Nationally Representative Sample of Korean Young Adults.

The purpose of this study was to investigate whether the intakes of some kinds of vitamins and minerals are associated with periodontitis in a nationally representative sample of young adults. This study comprised 2049 young adults aged 19-39 years who took both periodontal examination and nutrition survey. The vitamin and mineral intakes were calculated from dietary intake data gained by complete one-day 24-h recall interviews, and the intake levels for each nutrient were classified by the Recommended Nutrient Intake (RNI) in Dietary Reference Intakes for Koreans and median values. Periodontitis was assessed using Community Periodontal Index (CPI). Multivariate logistic regression analyses were performed in a whole sample and subgroups with the strata of gender or smoking, following a complex sampling design. In analyses according to RNI, a lower intake of niacin was significantly associated with periodontitis in young adults (odd ratio [OR] 1.47, 95% confidential interval [CI] 1.09-2.00) and in its subgroup of women (OR 1.70; 95% CI 1.10-2.64) and current non-smokers (OR 1.75; 95% CI 1.22-2.51). Whereas, in analyses according to median intake values, there were significant associations of periodontitis with a lower intake of niacin in women (OR 1.58; 95% CI 1.02-2.46) and current non-smokers (OR 1.50; 95% CI 1.01-2.22), with lower intake of vitamin C in women (OR 1.66; 95% CI 1.04-2.64) and in current non-smokers (OR 1.49; 95% CI 1.04-2.14), with lower intake of iron in women (OR 1.85; 95% CI 1.11-3.07), and with lower intake of vitamin A marginally in women (OR 1.56; 95% CI 1.00-2.44). In young adults, periodonitis is significantly associated with the lower intakes of niacin, vitamin C, and iron, especially in women and current non-smokers.

Synergistic effect of maternal obesity and periodontitis on preterm birth in women with pre-eclampsia: a prospective study.

AIM: The aim of this study was to investigate if pregnant women with both obesity and periodontitis are more likely to experience preterm birth (PTB) in women with pre-eclampsia (PE) than pregnant women with only obesity or only periodontitis. MATERIALS AND METHODS: The study examined a total of 328 pregnant women at 21-24 weeks of gestation. Overweight and obesity was defined based on criteria proposed by the WHO Expert Consultation. Periodontal conditions were assessed by measuring periodontal clinical attachment loss. PTB was defined as delivery at <37 weeks, and PE was defined as blood pressure higher than 140/90 mmHg on two separate occasions with at least 1+ proteinuria on a random urine screen after the 20th week of pregnancy. RESULTS: After adjusting for other important cofactors, pregnant women with periodontitis were 5.56 times [95% confidence interval (CI) = 1.22-25.39] more likely to have PTB with PE than women without periodontitis. The association was much stronger (odds ratio = 15.94, 95% CI = 3.31-76.71) in women with both obesity and periodontitis. CONCLUSIONS: Our results of this study indicate that pregnant women with both pre-pregnancy obesity and periodontitis are significantly more likely to have PTB with PE than pregnant women with only periodontitis.

Association between vitamin D deficiency and periodontal status in current smokers.

OBJECTIVES: The aim of this study was to examine whether vitamin D level is associated with periodontitis using a representative sample of Korean adults. METHODS: A total of 6011 subjects who participated in the fourth Korea National Health and Nutrition Examination Survey (KNHANES) were examined. Vitamin D deficiency was defined as 25-hydroxyvitamin D serum concentrations to be under or equal to 20 ng/ml. We assessed periodontal conditions by Community Periodontal Index (CPI) and defined higher CPI as ≥code 3. Multivariate logistic regression analyses were performed adjusting for sociodemographics, oral and general health behaviors, and systemic health status. All analyses considered a complex sampling design, and a subgroup analysis was performed to determine estimates stratified according to the effect modifier. RESULTS: There was no association between vitamin D deficiency and higher CPI after adjusting for the covariates in the total sample. According to the strata of smoking, the significant association was found in only current smokers after adjusting for the covariates including pack-years (odds ratio: 1.53, 95% confidence interval: 1.07-2.18). CONCLUSIONS: A significant association between vitamin D deficiency and periodontal status was found in only current smokers. Smoking could modify the effect of vitamin D on periodontitis.

Risk factors for dental caries in childhood: a five-year survival analysis.

OBJECTIVES: The purpose of this study was to examine the risk factors of dental caries at the level of an individual person with survival analysis of the prospective data for 5 years. METHODS: A total of 249 first-grade students participated in a follow-up study for 5 years. All participants responded to a questionnaire inquiring about socio-demographic variables and oral health behaviors. They also received an oral examination and were tested for Dentocult SM and LB. Over 5 years, the participants received yearly oral follow-up examinations to determine the incidence of dental caries. The incidence of one or more dental caries (DC1) and four or more dental caries (DC4) were defined as one or more and four or more decayed, missing, and filled permanent teeth increments, respectively. Socio-demographic variables, oral health behaviors, and status and caries activity tests were assessed as risk factors for DC1 and DC4. The adjusted hazard ratios (HRs) of risk factors for DC1 and DC4 were calculated using Cox proportional hazard regression models. RESULTS: During the 5-year follow-up period, DC1 and DC4 occurred in 87 and 25 participants, respectively. In multivariate hazard models, five or more decayed, missing, and filled primary molar teeth [HR 1.93, 95% confidence interval (CI) 1.19-3.13], and Dentocult LB of two or three (HR 2.21, 95% CI 1.37-3.56) were independent risk factors of DC1. For DC4, only Dentocult LB of two or three was an independent risk factor (HR 2.95, 95% CI 1.11-7.79). CONCLUSIONS: Our results suggest that dental caries incidence at an individual level can be associated with the experience of dental caries in primary teeth and Dentocult LB based on the survival models for the 5-year prospective data.

Association between plasma levels of manganese and periodontal status: a study based on the fourth Korean National Health and Nutrition Examination Survey.

BACKGROUND: This study aims to evaluate the association between plasma levels of manganese (Mn) and periodontal status in a representative sample of Korean adults. METHODS: Plasma levels of Mn and periodontal status were analyzed in 1,679 participants, all of whom were ≥19 years old. Plasma levels of Mn were divided into four quartiles: first (<1.057 µg/dL), second (1.057 to 1.274 µg/dL), third (1.275 to 1.544 µg/dL), and fourth (>1.544 µg/dL). Periodontal status was assessed using the Community Periodontal Index (CPI). Multivariate logistic regression analyses were performed after adjusting for sociodemographic variables, oral and general health behavior, oral health status, and systemic conditions. All analyses took into consideration the complex sampling design, and multivariate analyses were performed in the subgroups. RESULTS: Multivariate logistic regression analyses revealed a significant association between plasma levels of Mn and higher CPI in the total sample. There was a moderate association between first-quartile plasma levels of Mn and higher CPI in males (odds ratio [OR]: 2.13; 95% confidence interval [CI] 1.25 to 3.63) and current smokers (OR: 2.07; 95% CI 1.04 to 4.11), compared to the fourth quartile. CONCLUSION: Periodontal status is significantly associated with plasma levels of Mn in Korean adults, especially in men and smokers.

Association of dental caries with socioeconomic status in relation to different water fluoridation levels.

OBJECTIVES: The aim of this study was to assess the prevalence of dental caries in 11-year-old children, related to water fluoridation and family affluence scale (FAS), as an indicator of socioeconomic status (SES) in Korea. METHODS: A total of eight areas were selected for study: four areas with fluoridated piped water (WF areas) and four areas with nonfluoridated piped water (non-WF areas). Non-WF areas had a similar economic level and population size compared with the WF areas. A total of 1446 elementary school students, 11 years of age, were included. They were examined, and questionnaires completed by their parents were analyzed. In the questionnaire, information about gender, FAS as an indicator of SES, occasions of daily cariogenic snack intake, occasions of daily cariogenic beverage intake, drinking of piped water, cooking with piped water, and usage of oral hygiene supplemental measures were surveyed. The bivariate association between the characteristics of the subjects and the number of decayed, filled, and missing permanent teeth (DMFT score) was analyzed through an independent samples t-test. The difference in the mean DMFT score between different FAS groups was analyzed by DMFT ratio, after adjusting for gender, oral health behaviors, and usage of piped water variables. The DMFT ratio was calculated from a Poisson regression model, because the DMFT score was not normally distributed. RESULTS: There was no significant association between FAS and the mean DMFT score in both areas, by bivariate analysis. After adjusting for each group of confounders, a significant association (95% CI: 1.032-1.513) was found between the FAS and mean DMFT scores in non-WF areas; however, no significant difference was observed in the WF areas (95% CI: 0.766-1.382). CONCLUSIONS: This study supported that water fluoridation could not only lead to a lower prevalence of dental caries, but also help to reduce the effect of SES inequalities on oral health.

Association between periodontitis and preeclampsia in never-smokers: a prospective study.

AIM: The aim of this prospective study was to investigate the relationship between periodontitis and preeclampsia in never-smokers. MATERIALS AND METHODS: Pregnant women were recruited at 21 to 24 weeks of gestation from March 2009 to June 2013. Information on demographics, health behaviours, obstetric history, and systemic diseases that can influence periodontal status and preeclampsia was collected. Full-mouth periodontal probing was performed by two trained examiners. The inter-examiner Kappa value was 0.822 for clinical attachment loss (CAL). Periodontitis was defined as clinical periodontal attachment loss (CAL) of 4.0 mm or greater on 2 or more sites not on the same tooth. Information on the occurrence of preeclampsia was collected by five obstetricians. RESULTS: We studied a total of 283 subjects, comprised of 67 subjects with periodontitis and 216 subjects without periodontitis. Of these, 13 (4.6%) women were diagnosed with preeclampsia. After adjusting for all confounders, the adjusted odds ratio of periodontitis for preeclampsia was 5.56 (95% confidence interval of 1.49-20.71). CONCLUSIONS: There was a significant relationship between periodontitis and the occurrence of preeclampsia among never-smokers.

Association between harmful alcohol use and periodontal status according to gender and smoking.

BACKGROUND: the aim of this study is to assess the association of harmful alcohol use based on the alcohol use disorders identification test (AUDIT) score with periodontal status according to gender and smoking in a representative sample of Korean adults. METHODS: This study analyzed 5,291 participants older than 19 years whose data of harmful alcohol use and periodontal status were available. Harmful alcohol use was defined by the WHO guidelines for the administration of AUDIT. The periodontal status was assessed by the Community Periodontal Index (CPI). Multivariate logistic regression analysis was performed with adjustment for socio-demographic variables, oral and general health behavior, oral health status and systemic conditions. All analyses considered a complex sampling design, and multivariate analysis was also performed in the subgroups. RESULTS: Multivariate logistic regression analysis revealed a marginal association between harmful alcohol use and higher CPI in the total sample. The adjusted odds ratio (OR) of harmful alcohol use was 1.16 (0.97 to 1.38) for higher CPI. Higher CPI was significantly associated with harmful alcohol use in men (OR: 1.28; 95% CI: 1.03-1.60) and non-smokers (OR: 1.29; 95% CI: 1.06-1.57). CONCLUSION: Periodontal status is significantly associated with harmful alcohol use in men and non-smokers in a representative sample of Korean adults.

Association between obesity and periodontitis in pregnant females.

BACKGROUND: The purpose of this study is to investigate whether overweight and obesity before pregnancy are associated with periodontitis during pregnancy. METHODS: This study examined a total of 315 pregnant females at 21 to 24 weeks of gestation. Overweight and obesity were defined based on criteria proposed by the World Health Organization Expert Consultation. Periodontal conditions were assessed by measuring clinical periodontal attachment loss (AL). To investigate whether obese pregnant females have increased risk according to the extent of periodontitis, the data were divided into two groups: 1) generalized periodontitis and 2) localized periodontitis. A comparison among underweight, normal-weight, and overweight/obese groups for explanatory variables was analyzed using the χ(2) test for categorical variables and an analysis of variance for continuous variables. Multivariate logistic regression analysis was performed with adjustments for age, health and oral health behaviors, and obstetric information. RESULTS: Age, age at first delivery, periodontitis, and periodontal conditions (two or more interproximal sites with AL ≥4 mm not on the same tooth) were significantly associated with body mass index (BMI) (P <0.05). The adjusted odds ratio of periodontitis was 4.57 (95% confidence interval = 2.30 to 9.07) for overweight and obese females (BMI ≥23 kg/m(2)), after adjusting for all of the covariates. CONCLUSION: There is a strong association between prepregnancy overweight/obesity and periodontitis in pregnant females.

Systemic effect of water fluoridation on dental caries prevalence.

OBJECTIVES: The aim of this study was to evaluate the systemic effect of water fluoridation on dental caries prevalence and experience in Cheongju, South Korea, where water fluoridation ceased 7 years previously. METHODS: A cross-sectional survey was employed at two schools where water fluoridation had ceased (WF-ceased area) and at two schools where the water had never been fluoridated (non-WF area). The schools in the non-WF area were of a similar population size to the schools in the WF-ceased area. Children of three age groups were examined in both areas: aged 6 (n = 505), 8 (n = 513), and 11 years (n = 467). The differences in the mean number of decayed or filled primary teeth (dft) and the mean number of decayed, missing, or filled permanent teeth (DMFT) scores between areas after adjusting for oral health behaviors and socio-demographic factors were analyzed by a Poisson regression model. RESULTS: The regression model showed that the DMFT ratio for children aged 11 years in the WF-ceased area was 0.581 (95% CI 0.450-0.751). In contrast, the dft ratio for age 6 in the WF-ceased area was 1.158 (95% CI 1.004-1.335). Only the DMFT ratio for age 8 (0.924, 95% CI 0.625-1.368) was not significant. CONCLUSIONS: While 6-year-old children who had not ingested fluoridated water showed higher dft in the WF-ceased area than in the non-WF area, 11-year-old children in the WF-ceased area who had ingested fluoridated water for approximately 4 years after birth showed significantly lower DMFT than those in the non-WF area. This suggests that the systemic effect of fluoride intake through water fluoridation could be important for the prevention of dental caries.

The growth trends of Korean adolescents with bialveolar protrusion: a nine year longitudinal cephalometric study.

Bialveolar protrusion and dental crowding seems to have common features in terms of aetiology and treatment method, although they result in different facial profiles and tooth alignment. The aim of this longitudinal study is to determine when children begin to show bialveolar protrusive traits in order to get more clue about the aetiology of bialveolar protrusion. Longitudinal lateral cephalometric data of children followed from 6 to 14 years of age were used. A total of 155 children (81 girls and 74 boys) with showing Class molar relationships at the age of 14 were assigned to either the protrusive group (PG) or the non-protrusive group (NPG), based on 5 cephalometric measurements. The cephalometric measurements of these 2 groups were compared at each age separately in both sexes by independent t-tests. Throughout the entire observation period, there were differences between PG and NPG in both sexes in measurements which were used for classification at 14 years of age. There were differences between sexes in both PG and NPG in several measurements of at several different ages. Individuals with bialveolar protrusive traits at the age of 14 exhibited the signs early in life, at least from the early mixed dentition.