Rehabilitation of lost teeth related to maintenance of cognitive function.

OBJECTIVE: As the era of aging comes, cognitive impairment (CI) is increasing. The impact of rehabilitation of lost tooth on CI remains unclear. This study aimed to investigate whether non-rehabilitated lost teeth (NRLT) is associated with CI among Korean elders. METHODS: A total of 280 elders comprising of 140 cases and 140 age-sex-matched controls were included in this cross-sectional study. CI was assessed using the Mini-Mental Status Examination (MMSE). NRLT was evaluated using panoramic radiograph and oral examination. NRLT was categorized into low (≤4) and high (≥5). Age, sex, education, drinking, smoking, exercise, obesity, hypertension, subclinical atherosclerosis, glucose, cholesterol, depression, and denture-wearing were considered as confounders. Conditional multivariate logistic regression analysis was applied to assess the adjusted association. RESULTS: NRLT was associated with increased CI after controlling for confounders (odds ratio [OR] = 1.06, 95% confidence interval [95% CFI]: 1.00-1.13). However, lost teeth were not associated with CI. Those with high NRLT (≥5) compared to those with low NRLT (≤4) was more likely to have CI by 2.7 times (OR = 2.74, 95% CFI = 1.28-5.86). CONCLUSION: Our data showed that NRLT was independently associated with CI. Hence, rehabilitation of the lost teeth could be important for the maintenance of cognitive function.

Deep sequencing salivary proteins for periodontitis using proteomics.

OBJECTIVES: Saliva is a bodily fluid transuded from gingival crevice fluid and blood and contains many proteins. Proteins in saliva have been studied as markers for periodontal diseases. Mass spectrometric analysis is applied to investigate biomarker proteins that are related to periodontitis. MATERIAL AND METHODS: Saliva samples were collected from 207 participants including 36 pairs matched for age, sex, and smoking who joined Yangpyeong health cohort. Periodontitis was defined by 2005 5th European guideline. Shotgun proteomics was applied to detect proteins from saliva samples. Principal component analysis and Ingenuity Pathway Analysis for canonical pathway and protein pathway were applied. Protein-protein interaction was also applied. Enzyme-linked immunosorbent assay (ELISA) was used to verify the candidate protein markers among another matched participants (n = 80). RESULTS: Shotgun proteomics indicated that salivary S100A8 and S100A9 were candidate biomarkers for periodontitis. ELISA confirmed that both salivary S100A8 and S100A9 were higher in those with periodontitis compared to those without periodontitis (paired-t test, p < 0.05). CONCLUSION: Our proteomics data showed that S100A8 and S100A9 in saliva could be candidate biomarkers for periodontitis. The rapid-test-kit using salivary S100A8 and S100A9 will be a practical tool for reducing the risk of periodontitis and promotion of periodontal health. CLINICAL RELEVANCE: A rapid-test-kit using salivary biomarkers, S100A8 and S100A9, could be utilized by clinicians and individuals for screening periodontitis, which might reduce the morbidity of periodontitis and promote periodontal health.

Incipient periodontitis and salivary molecules among Korean adults: association and screening ability.

AIM: This study aims to evaluate the association of salivary matrix metalloproteinase-9 (MMP-9) and interleukin-8 (IL-8) with periodontitis and its screening ability on periodontitis. MATERIAL AND METHODS: We selected 693 participants from the Yanypyeong Cohort: 577 participants with periodontitis and 116 participants without periodontitis. Periodontitis was assessed by dentists using a panoramic radiograph. Salivary MMP-9 and IL-8 were assayed using multiplexed bead immunoassay (Luminex). MMP-9 and IL-8 were categorized into low, medium and high. Age, sex, income, smoking, drinking, exercise, obesity and metabolic syndrome were confounders. Logistic regression analysis was applied to evaluate the association between MMP-9, IL-8 and periodontitis. Receiver operating characteristic curve was applied for sensitivity, specificity and c-statistics. RESULTS: High MMP-9 and medium IL-8 were associated with periodontitis: adjusted odds ratio were 2.2 [95% confidence interval (CI): 1.3-3.7] for MMP-9 and 1.9 (95% CI: 1.1-3.4) for IL-8. The final screening model using salivary MMP-9 for periodontitis had a sensitivity of 0.46, specificity of 0.77 and c-statistic of 0.63 (p < 0.001). CONCLUSIONS: Our data show that salivary MMP-9 and IL-8 could be potential markers for periodontitis. The screening model for periodontitis could be useful in clinics and home. A future prospective study is indicated for predicting the occurrence of periodontitis.

The association of hypertension with periodontitis is highlighted in female adults: results from the Fourth Korea National Health and Nutrition Examination Survey.

AIM: To evaluate the association of hypertension and high systolic and diastolic blood pressure (SBP and DBP) with periodontitis in a nationally representative Korean adult population. MATERIALS AND METHODS: Total of 14,625 participants of Fourth Korea National Health and Nutrition Examination Survey (KNHANES IV) aged over 19 years were cross-sectionally surveyed. Periodontitis was defined as CPI score of 3 or 4. Hypertension was categorized as: normotensive (SBP < 120 mmHg and DBP < 80 mmHg), pre-hypertensive (120 < SBP < 140 mmHg or 80 < DBP < 90 mmHg) and hypertensive (SBP ≥ 140 mmHg or DBP ≥ 90 mmHg or taking antihypertensive medication). Multivariate Poisson regression analyses were performed controlling for age, sex, household income, drinking, smoking, physical activity, obesity, hypercholesterolaemia and diabetes mellitus. Stratified analyses were performed to identify specific risk groups. RESULTS: Hypertension showed a significant positive association with periodontitis in the fully adjusted model in female adults with a dose-response relationship. This association was highlighted in females aged 30-59 years (prevalence ratio = 1.25; 95% confidence interval: 1.11-1.40). The strength of the association was highest in females aged 30-39 years and decreased with increasing age. Among females aged 30-59 years, high-risk groups of this link were lower middle income quartile, never drinker and non-diabetes groups for both pre-hypertension and hypertension. CONCLUSION: Our data showed that hypertension was associated with periodontitis in Korean female adults independent of known confounders.

Genomewide association study on chronic periodontitis in Korean population: results from the Yangpyeong health cohort.

AIM: This study aims to locate the genes related to periodontitis through genome-wide association study (GWAS) in Korean population. METHODS: Total of 677 adults aged 44-88 years were recruited from the Yangpyeong cohort in Korea. The participants did not have self-reported metabolic diseases, cardiovascular diseases or cancer. Periodontitis was assessed using alveolar bone loss from a digital panoramic radiograph and classified into three groups: normal to mild, moderate and severe periodontitis. DNA from blood samples were genotyped using the Illumina Human 1M-duo Beadchip. Multivariable logistic regression analysis in PLINK was applied to examine the single-nucleotide polymorphisms (SNPs) related to periodontitis after controlling for various confounders. RESULTS: Associations of three SNPs suggested TENM2 (rs4242220) and LDLRAD4 (rs12969041, rs2027756) as putative risk genes of chronic periodontitis (p-values <1 × 10-5 ). The odds ratio [95% confidence interval (CI)] of TENM2 was 0.53 (0.40-0.70) for moderate periodontitis and that of LDLRAD4 was 2.86 (1.92-4.27) for severe periodontitis. Two nonsynonymous SNPs of protein coding region and seven SNPs selected from previous reports showed nominal association. CONCLUSION: Our GWAS supports a previously reported gene of TENM2 and newly suggests LDLRAD4. These two genes' role on lipid metabolism may play a part in the molecular aetiology of periodontitis.

Association of periodontitis with oral malodor in Korean adults.

This study aimed to evaluate the association of periodontitis with the organoleptic score (OLS)-defined oral malodor after validating OLS with odoriferous sulfur compounds in mouth air among Korean adults. A total of 330 adults aged 47-86 years were recruited from the Yangpyeong health cohort, South Korea, in 2015. Oral malodor was assessed using a 6-point OLS by a trained dentist and validated with the concentrations of hydrogen sulfide (HS) and methyl mercaptan (MM) using a gas chromatographer. Periodontitis was measured by assessing the radiographic alveolar bone loss on digital orthopantomography. Statistical analyses including descriptive statistics, partial correlation, ANOVA, and multivariable logistic regression with putative confounders were applied. OLS was significantly correlated with the concentrations of HS and MM (partial r = 0.401 and 0.392, respectively; both p<0.001) after controlling for confounders. Individuals with periodontitis had 1.8 times the risk of OLS-defined oral malodor in multivariable models (adjusted odds ratio = 1.77 in the model with the number of teeth and 1.82 in the model with denture wearing; p = 0.047 and 0.035, respectively). Periodontitis was associated with OLS-defined oral malodor among Korean adults independent of known confounders. Periodontal conditions should be considered for clinical practice and research of oral malodor.

The association of dietary vitamin C intake with periodontitis among Korean adults: Results from KNHANES â £.

BACKGROUNDS: The association of dietary vitamin C (vit C) on periodontitis requires more valid evidence from large representative samples to enable sufficient adjustments. This study aimed to evaluate the association between dietary vit C intake and periodontitis after controlling for various confounders in the representative Korean adult population. METHOD: A total of 10,930 Korean adults (≥19 years) from the fourth Korean National Health and Nutrition Examination Survey data set were included in this cross-sectional study. Periodontitis was defined as community periodontal index score of 3 or 4. Dietary vit C intake was estimated from a 24-hour dietary record, and categorized into adequate and inadequate according to the Korean Estimated Average Requirement value. Potential confounders included age, sex, income, frequency of tooth brushing, use of floss, dental visit, drinking, smoking, diabetes, hypercholesterolemia, hypertension, and obesity. A multivariable logistic regression analysis and stratified analysis were applied. RESULTS: Those with inadequate dietary vit C intake were more likely by 1.16 times to have periodontitis than those with adequate dietary vit C intake (adjusted odds ratio [aOR] = 1.16, 95% confidence interval = 1.04-1.29). Lowest and middle-low quartile of dietary vit C intake, compared to highest quartile of dietary vit C intake, showed significant association (aOR = 1.28 and 1.22 respectively), which was in a biological-gradient relationship (trend-p <0.05). CONCLUSIONS: Our data showed that inadequate dietary vit C intake was independently associated with periodontitis among Korean adults. Hence, adequate intake of dietary vitamin C could be substantially important on the promotion of periodontal health among Korean adults.

Association between periodontitis and salivary 8-hydroxydeoxyguanosine among Korean rural adults.

OBJECTIVES: This study aimed to evaluate the association between salivary 8-hydroxydeoxyguanosine (8-OHdG) and periodontitis among community-dwelling Korean adults. METHODS: A total of 211 adults (80 men and 131 women) were cross-sectionally surveyed from the Sunchang Longevity Cohort. Periodontitis was defined as having at least 30% of teeth with proximal attachment loss ≥5 mm. The salivary 8-OHdG level was categorized into tertiles: low (<0.916 ng/ml), medium (0.916 to <2.675 ng/ml) and high (≥2.675 ng/ml). Sociodemographic, habitual and systemic health-related factors were controlled for. Logistic regression analysis was performed for the outcome of severe periodontitis. Analysis of covariance in general linear model was performed for the outcome of 8-OHdG. RESULTS: The high 8-OHdG level showed a significant association with periodontitis. The odds ratio (95% confidence interval) was 2.40 (1.05-5.51), and it was highlighted by adding the interaction term with drinking and smoking. The adjusted mean log-transformed value of 8-OHdG was significantly higher in the severe periodontitis group (1.40 ng/ml) than in the control group (1.02 ng/ml) (ancova, P = 0.028). CONCLUSIONS: 8-OHdG was associated with periodontitis. Thus, salivary 8-OHdG could be a useful marker for periodontitis.

Periodontitis is associated with the risk of subclinical atherosclerosis and peripheral arterial disease in Korean adults.

BACKGROUND AND AIMS: We aimed to evaluate the association of periodontitis with the development of early atherosclerotic vascular disease in Korean adults. METHODS: In this cross-sectional study, a total of 1343 adults aged over 40 years were recruited from a community-based cohort of Yangpyeong county, Korea, during the period 2010-2014. Only dentate individuals were included in the study. Subclinical atherosclerosis (SA) was defined as carotid intima-media thickness (cIMT)≥0.754 mm, as assessed bilaterally by B-mode ultrasound. Peripheral arterial disease (PAD) was defined as ankle-brachial index (ABI)≤1.0, as measured by Doppler. History of periodontitis was assessed by measuring the radiographic alveolar bone loss (RABL) on a digital dental panorama and was classified into three groups: normal, moderate and severe periodontitis (≥2 non-adjacent interproximal sites with RABL≥4 mm and 6 mm, respectively). The associations of periodontitis with SA and PAD were evaluated by multivariable logistic regression analysis and analysis of covariance, adjusted for age, sex, education level, tooth loss, smoking, drinking, exercise, obesity, triglycerides, HDL, LDL, hs-CRP, diabetes and hypertension. Stratified analyses were performed to identify specific risk groups. RESULTS: After controlling for confounders, severe periodontitis was associated with SA [adjusted odds ratio (aOR) = 1.55; 95% confidence interval (CI): 1.07-2.24] and PAD (aOR = 2.03; 95% CI: 1.05-3.93). These associations were highlighted in never-smokers. For increasing severity of periodontitis, the adjusted mean cIMT increased (p = 0.011) while that of ABI decreased (p = 0.033). CONCLUSIONS: Our data showed that periodontitis is a substantially important risk factor for atherosclerotic vascular disease among Korean adults.

Periodontitis Is Associated with Cognitive Impairment in Elderly Koreans: Results from the Yangpyeong Cohort Study.

OBJECTIVES: To investigate the association between periodontitis and cognitive impairment in elderly Koreans. DESIGN: Cross-sectional study with age- and sex-matched case-control selection. SETTING: The Yangpyeong cardiovascular cohort (YCC), a part of the Korean Genome Epidemiologic Study (KoGES), Yangpyeong, South Korea. PARTICIPANTS: Individuals with cognitive impairment (n=65) and cognitively normal controls (n=124) aged 60 and older from the YCC. MEASUREMENTS: Alveolar bone loss was assessed on dental panoramic radiographs to categorize the cumulative history of periodontitis (HOP) into three groups: normal, moderate periodontitis, severe periodontitis. The Mini-Mental State Examination (MMSE) was used to categorize participants as cognitively normal or cognitively impaired. Age- and sex-matched conditional logistic regression models were used for analysis. Confounders considered in the analysis were age, sex, drinking, smoking, exercise, total cholesterol, total protein, body mass index, fasting plasma glucose, intima-media thickness, hypertension medication, and depression. RESULTS: Participants with HOP were more likely to have cognitive impairment than those without (odds ratio=2.14, 95% confidence interval=1.04-4.41). The interaction effect of smoking and exercise on periodontitis highlighted the link. CONCLUSION: Periodontitis was independently associated with cognitive impairment after controlling for various confounders. Further longitudinal research is needed to determine whether periodontitis plays a role in cognitive decline in older adults.

Korean version of child perceptions questionnaire and dental caries among Korean children.

Although dental caries has been a major oral health problem for children, the association between dental caries and oral health related quality of life has been still controversial. This study aims to evaluate the association between the Korean version of the Child Perceptions Questionnaire (K-CPQ) and dental caries among Korean children. Eight hundred one school children aged 8 to 14 years participated in this study. After the K-CPQ was validated we performed an association study. The K-CPQ was self-reported. Dental caries were evaluated by dentists using the World Health Organization Index. Correlation analyses (intraclass correlation coefficient, Cronbach's alpha and Pearson's correlation coefficient [r]) and linear regression models (partial r) including age, gender and type of school were applied. Untreated deciduous dental caries was associated with the K-CPQ(8-10) overall score (partial r = 0.15, P <0.05). The link was highlighted in the domains of functional limitation and emotional well-being. Filled teeth due to caries (FT) was associated with the K-CPQ11-14 overall domain (partial r = 0.14, P = 0.002) as well as with the oral symptoms domain (partial r = 0.16, P = 0.001). This association was highlighted among public school children. Our data indicate that K-CPQ was independently associated with dental caries. The K-CPQ could be a practical tool to evaluate the subjective oral health among Korean children aged 8 to 14.