Evaluation of the association between sleep duration and tooth loss among Korean adults: data from the Korean National Health and Nutrition Examination Survey (KNHANES 2012-2014)

Association of edentulism and obstructive sleep apnea: A systematic review

PURPOSE

Sleep apnea is a common and underdiagnosed sleep-related breathing disorder. This systematic review aimed to evaluate the scientific evidence regarding the association between obstructive sleep apnea (OSA) and edentulism.

METHODS

An electronic search was conducted through PubMed (MEDLINE), Scopus, and Cochrane Library, up to January 2024. A systematic approach was followed according to the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) statement guidelines. The literature search intended to retrieve all relevant clinical studies about any possible association between OSA and edentulism. Only publications in the English language were selected, and animal studies, in vitro studies, case reports, case series, technique presentation articles, and expert opinions were excluded.

RESULTS

A total of 23 studies met the inclusion criteria and were included in this systematic review. They were published between 1999 and 2023 and were all clinical studies. These studies examined a possible association between OSA and edentulism and all of them agreed on their positive relation. Tooth loss favors anatomic alterations that deteriorate breathing. The severity of OSA was related to the extent and duration of edentulism. Mean Apnea-Hypopnea Index (AHI) scores in edentulous patients were found to be two to three times higher in comparison to dentate individuals, although the statistical data about it are scarce. No agreement was reached, however, about the use of dentures during sleep time, since the data are controversial.

CONCLUSION

The findings suggest that there is a plausible association between edentulism and OSA. Tooth loss impairs significant anatomic alterations and increases the risk for OSA. However, clinical data are limited and heterogeneous so more clinical studies should be encouraged for more robust conclusions.

Negative health outcomes in long sleepers: The societal sleep restriction hypothesis

Society imposes work and school schedules, as well as social expectations, that militate against consistently obtaining more than 7-9 h of sleep every 24 h. For most but not all adults this sleep duration is adequate. But among those who consistently obtain more than 9 h of sleep per day ("long sleepers"), there likely exists a subpopulation of individuals who are nevertheless failing to obtain enough sleep to satisfy their physiological sleep needs - a consequence of "restricting" their daily sleep durations to whatever extent they can tolerate so as to conform as closely as possible to society's norms and expectations. It is hypothesized that the 'long sleep arm' of the seemingly paradoxical U-shaped relationship between sleep duration and negative health outcomes can be explained, at least in part, by the existence of a subpopulation of such 'sleep-restricted long sleepers.'

Sleep and periodontal health

Sleep is fundamental for health and well-being. An adequate amount and quality of sleep is a cardinal component of a healthy lifestyle at the basis of the prevention of many non-communicable chronic diseases. Recent evidence suggests that sleep disorders, particularly obstructive sleep apnea, represent an emerging risk factor for periodontal health. This review article provides a critical appraisal of the existing literature concerning the association between sleep duration, sleep quality, sleep disorders in general, and obstructive sleep apnea with periodontal diseases, including gingivitis and periodontitis. The putative mechanisms underlying these associations are described as well as the potential clinical implications for diagnosis and treatment.

Causal associations between sleep traits and temporomandibular disorders: a bidirectional mendelian randomization analysis

Objectives

This study aims to investigate the relationship between five sleep traits (insomnia, sleep duration, getting up in morning, snoring, and daytime nap) and temporomandibular disorders (TMD) using bi-directional Mendelian randomization.

Methods

The bi-directional Mendelian randomization study was conducted in two stages. Initially, sleep traits were examined as exposures while TMD was evaluated as an outcome, whereas the second step was reversed. The inverse variance weighted (IVW) method and other Mendelian randomization methods were used for analysis. Furthermore, we performed the MR-Egger intercept, MR-PRESSO, Cochran's Q test, and "Leave-one-out" to assess the levels of pleiotropy and heterogeneity.

Results

The IVW method indicates that getting up in the morning reduces the risk of developing TMD (OR = 0.50, 95% CI 0.30-0.81, p = 0.005), while insomnia may increase the risk of TMD (OR = 2.05, 95% CI 1.10-3.85, p = 0.025). However, other sleep traits are not associated with the risk of TMD, and having TMD does not alter an individual's sleep traits. After removing outliers, the results remained robust, with no pleiotropy detected.

Conclusion

Genetically determined difficulty in getting up in the morning and insomnia can increase the risk of TMD. By optimizing sleep, the risk of developing TMD can be reduced. This underscores the importance of sleep in preventing TMD.

Association of Sleep Duration with Tooth Loss and Periodontitis: Insights from the National Health and Nutrition Examination Surveys (2005-2020)

OBJECTIVE

Sleep disorders such as insomnia, apnea, and restless leg syndrome can negatively affect a person's overall health and may cause hypertension, heart failure, and coronary heart disease. Likewise, periodontitis, a gum disease, can lead to both physical and psychological health issues, exerting a considerable effect on one's overall well-being-periodontitis stands as a primary cause of tooth loss. Nevertheless, there has been insufficient research on the correlation between the amount of sleep individuals get and the occurrence of periodontitis/tooth loss among Americans. Therefore, this study aimed to assess the influence of sleep length on periodontitis in the American population.

METHODS

Periodontitis severity was classified (none, mild, moderate, and severe) using American Periodontal Association criteria. Sleep duration was assessed by self-reported data and categorized into three groups (deficient, adequate, and excessive). Tooth loss was assessed by the oral examination. To establish a connection between the duration of sleep and periodontitis/tooth loss, a weighted multivariable logistic regression analysis was employed. A GAM analysis and smooth curve fitting assessment were conducted to identify non-linear relationships. Subgroup, interaction, and mediation analyses were also performed.

RESULTS

The prevalence of tooth loss was significantly high, affecting 96.4% of the individuals, whereas 46.6% of the study sample experienced moderate to severe periodontitis. The average age of participants was 52.7 years. After adjusting for potential confounding factors, the analysis of weighted multivariable logistic regression revealed a significant association between sleep insufficiency and moderate/severe periodontitis (OR 1.15, 95% CI 1.01-1.30, P = 0.0298), as well as tooth loss (OR 1.16, 95% CI 1.01-1.33, P = 0.0371). Additionally, the research showed a correlation between the length of sleep and periodontitis that followed a U-shaped pattern. In addition, the analysis of mediation revealed that high blood pressure explained 7.0% (95% CI 4.0% to 12.9%; P < 0.0001) of the link between the amount of sleep and the likelihood of losing teeth.

CONCLUSION

Sleep duration was independently correlated with moderate/severe periodontitis/tooth loss and had a non-linear relationship.

Identification of the causal relationship between sleep quality, insomnia, and oral ulcers

BACKGROUND

Multiple epidemiological studies have posited a potential association between sleep quality and the risk of oral diseases, yet the resulting conclusions have remained contentious, and the presence of a causal link remains equivocal. In this study, we aimed to investigate the causal relationship between sleep duration, insomnia, and common oral diseases.

METHODS

We utilized genetic correlation and two-sample Mendelian randomization analyses based on summary statistics from genome-wide association studies of sleep duration (N = 460,099), insomnia (N = 462,341), mouth ulcer (N = 385,026), oral cavity cancer (N = 4,151), and periodontal disease (N = 527,652).

RESULTS

Our results revealed a negative genetic correlation between sleep duration and mouth ulcer (genetic correlation: -0.09, P = 0.007), while a positive genetic correlation between insomnia and mouth ulcer was observed (genetic correlation: 0.18, P = 2.51E-06). Furthermore, we demonstrated that longer sleep duration is significantly associated with a reduced risk of mouth ulcers (OR: 0.67, 95% CI: 0.54-0.83, P = 2.84E-04), whereas insomnia is nominally associated with an increased risk of mouth ulcers (OR: 1.40, 95% CI: 1.01-1.95, P = 0.044). In contrast, no significant association was detected between sleep quality and periodontal disease or oral cavity cancer.

CONCLUSIONS

This work provides robust evidence to support the notion that enhanced sleep quality may confer a decreased risk of oral ulcers, thereby bearing considerable clinical relevance.

Implications of sleep disorders for periodontitis

PURPOSE

Periodontitis is a chronic inflammatory disease caused by multi-factors. Sleep is a natural physiologic process, and the sleep duration, quality, and patterns might be associated with periodontitis. Meanwhile, periodontitis might in turn induce systemic inflammation and thus impact sleep in different ways as well.

METHODS

To investigate the bidirectional relationship between sleep disorder and periodontitis, a literature search was conducted to reveal the interaction and possible mechanism between these two diseases.

RESULTS

The results show that sleep disorders can affect the progression of periodontitis via some pathomechanisms, and periodontitis also has a reverse impact on sleep.

CONCLUSION

Although the epidemiologic and clinical trials found the possible associations between sleep disorder and periodontitis, their relationship is still not that explicit. Further studies are warranted to shed light on them, to improve preventive health care.

Sleep, physical activity, and sedentary behaviors as factors related to depression and health-related quality of life among older women living alone: a population-based study

BACKGROUND

Although the number of older women living alone (OWLA) has risen steadily in aging societies, and research has been conducted on depression and health-related quality of life (HRQoL) among older adults, research is scarce on the health behaviors of OWLA, including their sleep, physical activity, and sedentary behaviors. Hence, we aimed to identify factors related to depression and HRQoL among this subset of the population, focusing on their health behaviors, using Andersen's model as a research framework.

METHODS

Data for secondary analysis were from the Korean National Health and Nutritional Examination Survey (2014, 2016, 2018, and 2020). The inclusion criteria were (1) women aged 65 and older and (2) those living alone. We included 794 older South Korean women living alone from 31,051 respondents. We used hierarchical regression analysis, considering sampling weight and a complex sample design, to identify factors related to depression and HRQoL.

RESULTS

Among the health behavior factors of Andersen's model as a research framework, sleep was associated with depression, whereas physical activity and sedentary behaviors were related to HRQoL. Subjective health status, limited activity, and perceived stress were associated with both depression and HRQoL. Household income, as an enabling factor, was only associated with HRQoL. The final regression model explained 39% of the variance in depression (p < 0.001) and 37% of the variance in HRQoL (p < 0.001).

CONCLUSIONS

Our study highlights the importance of strategies to improve specific healthy behaviors that affect depression and HRQoL in OWLA. Appropriate interventions that target increasing physical activity and quality of sleep, and decreasing sedentary behaviors, will be effective to enhance the well-being of OWLA. Healthcare providers should comprehensively understand the characteristics of OWLA and pay more attention to enabling, need, and health behavior factors.

Association between tooth loss and hypertension: A systematic review and meta-analysis

OBJECTIVES

Poor oral health status may increase the risk of cardiovascular disease. However, whether a specific association exists between tooth loss and hypertension is inconclusive. Accordingly, a quantitative systematic review was conducted to investigate the relationship between tooth loss and hypertension.

METHODS

Systematic search, data analysis and quality assessment were conducted on relevant literature published in PubMed, Embase, Web of Science and Cochrane Libraries until October 2021. Odds ratio (OR) with 95% confidence interval (CI) was used as effect size to evaluate the association between tooth loss and hypertension. Meta-regression and subgroup analyses were performed to identify whether difference was associated with study-level factors.

RESULTS

Of the 56 studies selected, 28 studies in 16 different countries involving 1,224,821 individuals were eligible for the systematic review. After adjustment for confounding factors, individuals with tooth loss had a higher risk for hypertension (OR 1.20; 95%CI 1.10-1.30, I² = 40.02%). With respect to the risk of hypertension on tooth loss, individuals with hypertension still had a higher risk for tooth loss (OR 1.35; 95%CI 1.07-1.62, I² = 51.10%). Age limitation of the included population is the major source of heterogeneity. However, studies in which the population was limited to the elderly did not report an increase in association between tooth loss and hypertension compared with studies without age limitation.

CONCLUSIONS

The results suggest a bidirectional association between tooth loss and hypertension. Future longitudinal prospective studies are required to establish causality between tooth loss and hypertension.

CLINICAL SIGNIFICANCE

Subjects with severe tooth loss should be carefully monitored for the manifestation of hypertension. The oral health status of hypertensive patients should also be meticulous maintained to prevent unwarranted tooth loss.

Evaluation of the association between periodontitis and risk of Parkinson's disease: a nationwide retrospective cohort study

The objective of this study was to examine the association between periodontitis and risk of incident Parkinson’s disease using large-scale cohort data on the entire population of South Korea. Health checkup data from 6,856,180 participants aged 40 and older were provided by the National Health Insurance Service of South Korea between January 1, 2009, and December 31, 2009, and the data were followed until December 31, 2017. The hazard ratio (HR) of Parkinson’s disease and 95% confidence interval (CI) were estimated using a Cox proportional hazards model adjusted for potential confounders. The incidence probability of Parkinson’s disease was positively correlated with the presence of periodontitis. The HR of Parkinson’s disease for the participants without the need of further dentist visits was 0.96 (95% CI 0.921–1.002); the HR of Parkinson’s disease increased to 1.142 (95% CI 1.094–1.193) for the individuals who needed further dentist visits. Compared to individuals without periodontitis and without metabolic syndrome, the HR of incident Parkinson’s disease gradually increased for individuals with periodontitis, with metabolic syndrome, and with both periodontitis and metabolic syndrome. People with periodontitis and metabolic syndrome had the highest HR of incident Parkinson’s disease, at 1.167 (95% CI 1.118–1.219). In conclusion, a weak association between periodontitis and Parkinson’s disease was suggested after adjusting for confounding factors from the population-based large-scale cohort of the entire South Korean population.

Are periodontal diseases associated with sleep duration or sleep quality? A systematic review

OBJECTIVES

This study aimed to systematically review the associations between periodontal diseases/tooth loss and sleep duration/quality.

MATERIAL AND METHODS

PubMed, Scopus, and Embase databases were searched (up to May 2021) to identify studies that assessed the association between periodontal diseases or number of teeth with sleep quality and sleep duration. Two researchers independently selected the studies and extracted the data. Considering the high heterogeneity among the included studies, meta-analysis was deemed unviable. Results are presented descriptively for sleep quality (studies that have used PSQI), self-reported sleep hours, and other tools that assessed sleep patterns.

RESULTS

Twenty studies (16 cross-sectional, two case-control, and two cohort) were included. Eight studies used the Pittsburgh Sleep Quality Index (PSQI) to assess quality of sleep. Six of these studies demonstrated that individuals with worse periodontal conditions demonstrated poorer sleep quality. However, most of the included studies that performed adjusted analysis showed no statistically significant association between self-reported hours of sleep and periodontitis. The mean number of present teeth was assessed in four studies; three of them demonstrated lower numbers of present teeth in individuals with inadequate sleep.

CONCLUSION

The literature shows conflicting results for the association between sleep hours and periodontitis. However, inadequate sleep may be associated with lower number of present teeth and periodontal diseases. Further studies are necessary in order to confirm these results.

Tooth loss as a potential risk factor for deficient sleep: an analysis of a nationally representative sample of adults in the USA

PURPOSE

Sleep deficiency is implicated as a risk factor for several systemic conditions. Loss of teeth has a profound effect on the individual's physiologic and psychologic health and quality of life. This study aimed to assess the association between tooth loss and sleep duration and determine if anterior and/or posterior tooth loss is a significant predictor.

METHODS

A total of 22,483 individuals ≥ 18 years who participated in the United States National Health and Nutrition Examination Survey (NHANES) 2005-2016 cycles were included. Multinomial logistic regression adjusted for age, gender, race/ethnicity, smoking, diabetes, body mass index, socioeconomic level, education, alcohol, and depression was performed to examine the association between sleep duration and tooth loss.

RESULTS

Compared to individuals with > 20 remaining teeth, those who were completely edentulous, had 1-10 or 11-20 teeth remaining were more likely to be in the deficient sleep category (OR [95% CI] = 1.59 [1.35-1.87], 1.29 [1.07-1.54], and 1.26 [1.11-1.43], respectively). When the numbers of both missing anterior and posterior teeth were entered in the model, only posterior teeth were significant. There was a 4% increase in the odds of being in the deficient sleep category for each missing posterior tooth (OR [95% CI] = 1.04 [1.02-1.05]).

CONCLUSIONS

Tooth loss was significantly associated with deficient sleep and posterior tooth loss appeared to be the main contributor. Although further research is needed to clarify the nature of this association, our results suggest that improving oral health might have an impact on overall health and quality of life.

Association between metabolic syndrome and tooth loss: A systematic review and meta-analysis

BACKGROUND

The authors conducted a systematic review and meta-analysis to verify the existence and level of scientific evidence concerning the association between metabolic syndrome (MetS), as the main exposure, and tooth loss (TL), as the outcome.

TYPES OF STUDIES REVIEWED

Through electronic databases and partially through gray literature, the authors identified observational studies in adults. The authors used no date or language restrictions. The authors evaluated the studies' methodological quality by using the Newcastle-Ottawa Scale. The authors conducted a random-effects model meta-analysis. The authors assessed the quality of evidence by using the Grading of Recommendations Assessment, Development and Evaluation criteria.

RESULTS

Twelve studies met the eligibility criteria, and 9 were retained for the meta-analysis. Most were cross-sectional studies with good methodological quality. Participants with MetS had fewer teeth (standardized mean difference, -2.77; 95% confidence interval, -4.56 to -0.98) and an increased likelihood of lacking functional dentition (odds ratio, 2.37; 95% confidence interval, 1.89 to 2.96) than did those without MetS. The overall quality of evidence was very low.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

Better-conducted longitudinal studies are necessary to establish a causal relationship between MetS and TL to inform the best strategies to prevent TL in populations with MetS.