Association between tooth loss and cognitive impairment in community-dwelling older Japanese adults: a 4-year prospective cohort study from the Ohasama study

Effects of intracerebral noradrenaline on cognitive decline associated with the loss of occlusal support

PURPOSE

The lack of occlusal support reportedly reduces cognitive function; however, the underlying mechanisms remain unclear. The locus coeruleus, which is located adjacent to the trigeminal mesencephalic nucleus, secretes noradrenaline throughout the brain. In this study, we evaluated the effects of noradrenaline in the hippocampus and cerebral cortex on cognitive decline following tooth extraction in rats.

METHODS

We performed passive avoidance experiments on male Wistar rats with extracted maxillary molars and determined the neuron density in the locus coeruleus and trigeminal mesencephalic nucleus using immunostaining and Nissl staining, respectively. We also assessed noradrenaline concentrations in the hippocampus and cerebral cortex using enzyme-linked immunosorbent assay.

RESULTS

In the passive avoidance experiment, the latency in the bright compartment was significantly shorter (P < 0.05) in the extraction group than in the control group. The numbers of cells in the locus coeruleus and trigeminal nucleus were significantly lower (P < 0.05) in the extraction group compared to those in the control group. The noradrenaline levels in the hippocampus and cerebral cortex were also significantly lower (P < 0.05) in the extraction group than those in the control group.

CONCLUSIONS

The lack of occlusal support associated with tooth extraction reduces the number of cells in the trigeminal mesencephalic nucleus and locus coeruleus, which may reduce the supply of noradrenaline to the cerebral cortex and hippocampus, leading to a decline in cognitive function.

Unlocking the Therapeutic Potential of Oral Cancer Stem Cell-Derived Exosomes

Oral cancer (OC) presents a significant global health burden with rising incidence rates. Despite advancements in diagnosis and treatments, the survival rate for OC patients, particularly those with advanced or recurrent disease, remains low at approximately 20%. This poor prognosis is often due to a small population of cancer stem cells (CSCs) that are capable of self-renewal and immune evasion, playing pivotal roles in proliferation, tumor initiation, progression, metastasis, and therapy resistance. Exosomes, which are nano-sized extracellular vesicles (EVs), have emerged as crucial mediators of cell-to-cell communication within the tumor microenvironment (TME). These vesicles carry diverse molecules such as DNA, RNA, proteins, lipids, and metabolites, influencing various cellular processes. Emerging evidence suggests that CSC-derived EVs significantly promote tumor progression and metastasis and maintain the balance between CSCs and non-CSCs, which is vital for intracellular communication within the TME of oral cancer. Recent reports indicate that oral cancer stem cell-derived EVs (OCSC-EVs) influence stemness, immune evasion, metastasis, angiogenesis, tumor reoccurrence, and drug resistance. Understanding OCSC-EVs could significantly improve oral cancer diagnosis, prognosis, and therapy. In this mini-review, we explore OCSC-derived exosomes in oral cancer, examining their potential as diagnostic and prognostic biomarkers that reflect CSC characteristics, and delve into their therapeutic implications, emphasizing their roles in tumor progression and therapy resistance. However, despite their promising potential, several challenges remain, including the need to standardize isolation and characterization methods and to elucidate exosome-mediated mechanisms. Thus, a comprehensive understanding of OCSC-EVs could pave the way for innovative therapeutic strategies that have the potential to improve clinical outcomes for OC patients.

Association between tooth loss-related speech and psychosocial impairment with cognitive function: A pilot study in Hong Kong's older population

BACKGROUND

Tooth loss has been associated with cognitive decline, but the underlying mechanisms involving speech and psychosocial impairment remain unclear.

OBJECTIVES

To investigate the impact of tooth loss-related speech and psychosocial impairment on cognitive function in Hong Kong's older population.

METHODS

Seventy-six Cantonese-speaking participants between the ages of 51-92 were classified into three groups: patients with complete dentures (CD), partially edentulous patients with less than 10 occluding tooth pairs (OU <10), and at least 10 occluding tooth pairs (OU ≥10). Cognitive function was assessed using the Montreal Cognitive Assessment Hong Kong Version, One-minute Verbal Fluency Task and Hayling Sentence Completion Test. Objective and subjective speech assessments were carried out using artificial intelligence speech recognition algorithm and a self-designed speech questionnaire. The impact of tooth loss on psychosocial condition was evaluated by the Reading the Mind in the Eyes Test and a self-designed questionnaire. Statistical analyses (one-way ANOVA, ANCOVA, Kruskal-Wallis test, Spearman correlation test) were performed.

RESULTS

Tooth loss was significantly associated with lower cognitive function (p = .008), speech accuracy (p = .018) and verbal fluency (p = .001). Correlations were found between cognitive function and speech accuracy (p < .0001). No significant difference in tooth loss-related psychosocial impact was found between the three groups.

CONCLUSION

While warranting larger sample sizes, this pilot study highlights the need for further research on the role of speech in the association between tooth loss and cognitive function. The potential cognitive impact of tooth retention, together with its known biological and proprioceptive benefits, supports the preservation of the natural dentition.

A prospective association between social isolation and cognitive performance among older adults in Europe: the role of loneliness and poor oral health

OBJECTIVES

The relationship between social isolation, loneliness, and tooth loss and cognition in older people is poorly understood. We examine how social isolation and cognitive performance are associated prospectively among older adults, as well as how tooth loss and loneliness are related to this association.

METHODS

Using data from 26,168 participants aged ≥50 from the Survey of Health, Ageing and Retirement in Europe (SHARE), we explored the association between social isolation, loneliness, tooth loss and cognition. We used bootstrapping with resampling strategies for testing a moderated mediating model.

RESULTS

Higher social isolation was associated with poorer cognitive performance (B = -0.20, 95% CI = -0.03, -0.01; R2 =0.60), an association mediated by the respondent's number of missing teeth (B = -0.001, 95% CI = -0.002, -0.001). Higher levels of social isolation were associated with a greater number of missing teeth, and a higher number of missing teeth was linked with poorer cognition. We also found that loneliness moderated the relationship between social isolation and both the number of missing teeth (B = -0.11, p  = 0.047) and cognitive performance.

CONCLUSION

In later life, social isolation and loneliness are associated with shoddy oral health and poor cognitive status. Clinicians and policymakers should be aware of both the association between social isolation and feelings of loneliness on dentition and oral health and their relationship to the cognitive status of older adults.

Functional dentition and well-being among Chilean 80-year-olds

BACKGROUND

The Decade of Healthy Aging 2021-2030 calls for a strengthening of the policies for older people in Latin America. An example of successful oral aging is the Japanese "8020" campaign, which achieved 50% of people aged 80 years having ≥20 teeth by 2016.

OBJECTIVE

To evaluate the association between having a functional dentition (≥20 teeth) and cognitive health, social participation, and quality of life in people aged ≥80 years.

METHODS

Cross-sectional data from 299 complete observations (weighted N = 436 981) of individuals aged ≥80 years from Chile's National Health Survey 2016-2017 were included (3% of the population; total = 5520 clinical observations/weighted N = 14 518 969). Generalised structural equation models (GSEM) evaluated the association between having a functional dentition and cognitive health, measured with the Mini-mental score, between having a functional dentition and social participation, and between having a functional dentition and quality of life, measured with the EQ-5D-3L. Models included the effect of mediators (daily fruit and vegetable consumption; oral health-related quality of life score) and controlled for the exposure-induced mediator-outcome variables: sex, educational level, and location. Data were analysed using the STATA-17 survey module. Statistical significance was set at P < .05 (95% confidence interval [CI]).

RESULTS

The sample was mostly female, had <8 years of education, and lived in urban areas. The prevalence of a functional dentition was 9.2% (95% CI 3.6,21.3/n = 21). GSEM demonstrated that the association between functional dentition and cognitive health was mediated by daily fruits and vegetables consumption (β = 0.12/95% CI 0.02,0.21/P = .015), with moderate strength of evidence. Additionally, there was strong evidence of an association between functional dentition and social participation frequency (β = 2.76/95% CI 0.60,4.73/P = .009). Finally, the association between functional dentition and quality of life was mediated by cognitive health (β =0.05/95% CI 0.02,0.09/P = .002) and oral health-related quality of life (β = -0.04/95% CI -0.08 to -0.01/P = .025), with strong and moderate evidence, respectively.

CONCLUSION

Given the beneficial implications of functional dentition in social participation, nutritional benefits and quality of life and well-being of individuals aged ≥80 years.

Prediction of Cognitive Impairment Risk among Older Adults: A Machine Learning-Based Comparative Study and Model Development

INTRODUCTION

The prevalence of cognitive impairment and dementia in the older population is increasing, and thereby, early detection of cognitive decline is essential for effective intervention.

METHODS

This study included 2,288 participants with normal cognitive function from the Ma'anshan Healthy Aging Cohort Study. Forty-two potential predictors, including demographic characteristics, chronic diseases, lifestyle factors, anthropometric indices, physical function, and baseline cognitive function, were selected based on clinical importance and previous research. The dataset was partitioned into training, validation, and test sets in a proportion of 60% for training, 20% for validation, and 20% for testing, respectively. Recursive feature elimination was used for feature selection, followed by six machine learning algorithms that were employed for model development. The performance of the models was evaluated using area under the curve (AUC), specificity, sensitivity, and accuracy. Moreover, SHapley Additive exPlanations (SHAP) was conducted to access the interpretability of the final selected model and to gain insights into the impact of features on the prediction outcomes. SHAP force plots were established to vividly show the application of the prediction model at the individual level.

RESULTS

The final predictive model based on the Naive Bayes algorithm achieved an AUC of 0.820 (95% CI, 0.773-0.887) on the test set, outperforming other algorithms. The top ten influential features in the model included baseline Mini-Mental State Examination (MMSE), education, self-reported economic status, collective or social activities, Pittsburgh sleep quality index (PSQI), body mass index, systolic blood pressure, diastolic blood pressure, instrumental activities of daily living, and age. The model demonstrated the potential to identify individuals at a higher risk of cognitive impairment within 3 years from older adults.

CONCLUSION

The predictive model developed in this study contributes to the early detection of cognitive impairment in older adults by primary healthcare staff in community settings.

Tooth loss impairs cognitive function in SAMP8 mice via the NLRP3/Caspase-1 pathway

OBJECTIVE

Loss of occlusal support due to tooth loss has been indicated as one of the risk factors for Alzheimer's disease. This study aimed to investigate the relationship between tooth loss and cognitive dysfunction and illustrate the role of neuroinflammation in advancing Alzheimer's disease.

MATERIALS AND METHODS

Male 5-month-old senescence-accelerated mouse strain P8 (SAMP8) mice were divided into three groups (n = 7): the C (control), S (sham-operated), and TL (tooth loss) groups. The Morris water maze (MWM) test was performed to assess spatial memory. Additionally, histopathological and molecular assessments of hippocampal tissues were performed.

RESULTS

The TL groups exhibited impaired spatial memory in the water maze. Tooth loss induced higher protein expression levels of the neuroinflammation cytokine interleukin-1β (IL-1β) in the hippocampus than in the S and C groups. Tooth loss activated the NLRP3 inflammasome and increased the expression of Caspase-1 in the hippocampus.

CONCLUSIONS

The findings indicated that tooth loss impairs cognitive function in SAMP8 mice and is closely related to the activation of NLRP3/Caspase-1 in the hippocampus.

Association between periodontitis treatment and dementia in Taiwanese adults

BACKGROUND

The chronic systemic inflammatory response in periodontitis may be a potential risk factor for dementia, especially in adults. This study determined the association between periodontal treatment and dementia in adults and evaluated the effect of regular scaling treatment on the risk of dementia in this population.

METHODS

This case-control study identified 18,930 patients with a dementia-related diagnosis from the Taiwan National Health Insurance Research Database. Scaling and periodontal emergency treatments were evaluated after 1 year and 3 years. Using multivariable logistic regression analysis to evaluate the association between periodontal emergency treatment and dementia risk.

RESULTS

The results showed that scaling treatment rates were lower in the dementia cohort than the non-dementia cohort after 1 and 3 years. Patients who received periodontal emergency treatment within 3 years had a significantly increased risk of dementia. Furthermore, patients with periodontitis who did not receive scaling treatment within 3 years had a higher risk of dementia than patients without periodontitis (OR, 1.22; 95% CI, 1.10-1.35).

CONCLUSION

This study demonstrated that periodontitis and dementia are associated, and that periodontitis is a risk factor for dementia in adults. The risk of dementia was dependent on the periodontal health status of adults, and our findings suggest that regular scaling can reduce the incidence of dementia in adults. Therefore, regular and routine scaling treatment is suggested for adults.

Tooth Loss as a Predictor of Long-Term Care Requirements in the Elderly: A Study in Kobe City, Japan

INTRODUCTION

The Kobe project, which utilizes prospective data from the national health insurance system, focuses on early detection and preventive strategies through the Frail Kenshin health check-up program. Previous research has underscored the correlation between tooth loss and the decline in physical and cognitive functions. In this study, using Kobe project data, we examined the link between remaining teeth and long-term care needs in individuals aged 64-65 years, with primary and secondary objectives involving various health parameters and quality of life.

METHODS

We analyzed baseline data from a prospective study conducted alongside the Frail Check program for generally healthy individuals aged 64-65 years to examine the relationship between the number of remaining teeth and various health indicators. This study focused on citizens aged 64-65 years to identify those at risk of needing long-term care by the age of 65 years.

RESULTS

Data from 1,530 participants were obtained, excluding eight individuals for specific reasons. At the end of the follow-up period, 41 (2.7%) individuals required support and 15 (1.0%) needed long-term care alone. The data revealed a significant association between the number of remaining teeth and the need for long-term care or support, as demonstrated by the Cochran-Armitage trend test (p<0.001). Although trends were noted for nutrition and total Cognitive Functional Instrument Self scores, they did not reach statistical significance. Additionally, a decrease in the number of remaining teeth was significantly associated with worse European Quality of Life Five Dimensions (EQ-5D-5L) visual analog scale scores, mobility, and regular activities (p<0.001).

CONCLUSION

Tooth loss indicates the potential long-term care needs of older adults. Monitoring oral health is crucial for addressing care requirements.

Tooth loss and dementia amongst older adults residing in long-term care facilities in Vancouver: A case-control study

OBJECTIVE

The purpose of this case-control study was to determine the association between dementia and the number of missing teeth, functional occlusal units and denture use in older adults residing in Long-Term Care (LTC) facilities.

BACKGROUND

Many studies have shown an association between dementia and tooth loss. However, few studies with a large sample size have been reported describing the relationship between dementia and the number of missing teeth, remaining teeth and functional occlusal units.

METHODS

An oral health assessment database of 2160 older adults admitted to LTC facilities in Vancouver, Canada, between 2015-2019 was utilised. Participants with a diagnosis of dementia in their medical records (N = 1174) were compared to those without dementia (N = 986). Multiple logistic regression analysis was used to explore a potential association between the number of missing teeth, functional occlusal units and the use of dentures and dementia.

RESULTS

The number of remaining teeth (OR = 1.0, 95% Confidence Interval = 1.0-1.0; P = .054) and number of functional occlusal units (OR = 1.0, 95% CI = 1.0-1.0; P = .059) were not associated with dementia after adjusting for age, sex, oral self-care and systemic conditions. Denture use (OR = 1.1, 95% CI = 0.5-2.4; P = .790) was not associated with dementia in edentulous patients.

CONCLUSION

There was no association between dementia and the number of remaining teeth, functional occlusal units or wearing dentures.

Association between Dental Diseases and Oral Hygiene Care and the Risk of Dementia: A Retrospective Cohort Study

OBJECTIVES

To investigate the associations of dental diseases and oral hygiene care with the risk of dementia.

DESIGN

Retrospective longitudinal cohort study.

SETTING AND PARTICIPANTS

We conducted a population-based study of individuals in the Korean National Health Insurance System. A total of 2,555,618 participants who underwent cardiovascular and dental screenings in 2008 were included.

METHODS

Dental diseases including periodontal diseases, dental caries, and tooth loss were assessed by dentists. Information on oral hygiene care, including professional dental cleaning and the frequency of tooth brushing, was collected using a self-administered questionnaire. Study outcomes were all-cause dementia, Alzheimer's disease (AD), and vascular dementia (VaD).

RESULTS

Periodontal diseases [adjusted hazard ratio (aHR) 1.07, 95% CI 1.04-1.09], dental caries (aHR 1.03, 95% CI 1.00-1.05), and 8-14 missing teeth (aHR 1.07, 95% CI 1.02-1.12) were associated with an increased risk of all-cause dementia. In contrast, either professional dental cleaning or frequent tooth brushing were associated with decreased risks of all-cause dementia (aHR 0.91, 95% CI 0.89-0.93 each; aHR 0.83, 95% CI 0.80-0.86 for both). The increased risks by dental diseases were reduced by oral hygiene care: periodontal diseases with professional dental cleaning (aHR 0.94, 95% CI 0.91-0.98) or tooth brushing ≥2 times/day (aHR 0.97, 95% CI 0.94-1.00) and 1 to 7 missing teeth with professional dental cleaning (aHR 0.94, 95% CI 0.89-0.98) or tooth brushing ≥2 times/day (aHR 0.92, 95% CI 0.89-0.95). Consistent results were noted for AD and VaD and in various subgroup analyses.

CONCLUSION AND IMPLICATIONS

Periodontal disease, dental caries, and a high number of missing teeth were independently associated with a higher risk of dementia. Conversely, improved oral hygiene care, such as professional dental cleaning and frequent tooth brushing, may modify the risk of dementia associated with dental diseases.

Increased Risk of Tooth Loss in Postmenopausal Women With Prevalent Vertebral Fractures: An Observational Study

The association between prevalent fractures and tooth loss in postmenopausal women remains unclear. Herein, we investigated the association between prevalent vertebral and nonvertebral fractures, the number of teeth present at baseline, and the number of teeth lost during follow-up in postmenopausal Japanese women. This cross-sectional study enrolled 843 participants (mean age 68.3 years). The number of teeth at follow-up was evaluated in 655 women in this longitudinal study. The participants were divided into four groups according to their prevalent fracture status: no fractures, vertebral fractures alone, nonvertebral fractures alone, and both fracture types. After adjusting for covariates, Poisson regression analyses were performed to investigate differences in the number of teeth at baseline and that lost during the follow-up period among the four groups. Participants with prevalent vertebral fractures alone had significantly fewer teeth at baseline than those in participants without fractures or nonvertebral fractures alone (p < 0.001 for both). Furthermore, they lost more teeth during the follow-up period than did those with no fractures (p = 0.021) and tended to lose more teeth than did those with nonvertebral fractures alone or both prevalent fracture types. We observed no significant difference in the number of teeth lost between the participants with nonvertebral fractures alone and those with no fractures. Postmenopausal women with prevalent vertebral fractures may be at a higher risk of tooth loss. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Poor Oral Health Linked with Higher Risk of Alzheimer's Disease

Alzheimer's disease (AD) is a multifactorial neurodegenerative disease characterized by cognitive and behavioral changes in older adults. Emerging evidence suggests poor oral health is associated with AD, but there is a lack of large-scale clinical studies demonstrating this link. Herein, we used the TriNetX database to generate clinical cohorts and assess the risk of AD and survival among >30 million de-identified subjects with normal oral health (n = 31,418,814) and poor oral health (n = 1,232,751). There was a greater than two-fold increase in AD risk in the poor oral health cohort compared to the normal oral health group (risk ratio (RR): 2.363, (95% confidence interval: 2.326, 2.401)). To reduce potential bias, we performed retrospective propensity score matching for age, gender, and multiple laboratory measures. After matching, the cohorts had no significant differences in survival probability. Furthermore, when comparing multiple oral conditions, diseases related to tooth loss were the most significant risk factor for AD (RR: 3.186, (95% CI: 3.007, 3.376)). Our results suggest that oral health may be important in AD risk, regardless of age, gender, or laboratory measures. However, more large-scale cohort studies are necessary to validate these findings and further evaluate links between oral health and AD.

Association of tooth count with cognitive decline and dementia in the Finnish adult population

AIM

To evaluate whether tooth loss is associated with cognitive decline and incident dementia.

MATERIALS AND METHODS

We analysed data from the Finnish population-based Health 2000 and follow-up Health 2011 surveys (participants aged ≥30 years and without dementia at baseline; N = 5506 at baseline and 3426 at 11-year follow-up). Dementia diagnoses until 2015 were ascertained from national registers (N = 5542). Tooth count was dichotomized as adequate (≥20) versus tooth loss (<20). Tooth loss was further stratified into 10-19 teeth, 1-9 teeth and edentulism. Upper and lower jaws were also considered separately. Baseline cognitive test scores were dichotomized by median as high versus low, and 11-year change as decline versus no decline.

RESULTS

Tooth loss (<20) was associated with lower baseline overall cognition (odds ratio [OR] = 1.21, 95% confidence interval [CI] = 1.03-1.43), 11-year cognitive decline (OR = 1.30, 95% CI = 1.05-1.70) and higher 15-year dementia risk (hazard ratio = 1.52, 95% CI = 1.15-2.02) after adjusting for multiple confounders. After adjustment for dentures, associations became non-significant, except for 10-19 teeth remaining and dementia. Results were similar after considering reverse causality bias; however, 10-19 teeth remaining was significantly associated with 11-year cognitive decline even after adjustment for dentures. No jaw-specific differences were observed.

CONCLUSIONS

Tooth loss adversely impacts the risk of cognitive decline and dementia. The role of dentures should be further explored.

Effects of Muscular Strength Training on Oral Health and Quality of Life: Using Korean Panel Survey Data, a Cross-Sectional Study

OBJECTIVES

The purpose of this study is to confirm the importance of muscular strength exercise by confirming the relationship between strength exercise, oral health, and quality of life.

METHODS

Using the 2019 and 2021 of the Korean National Health and Nutrition Examination Survey (KNHANES), 6535 people were selected as subjects. Complex sampling analysis was applied to all analyses; 2267 people were in the muscular strength training group (MSG), and 5841 people were in the non-muscular strength training group (NMSG). A multi-sample linear regression analysis was conducted to confirm the effect of muscular strength training on oral health and quality of life.

RESULTS

As a result of confirming the effect of muscular strength training on oral health status, problems with chewing decreased by 0.105, and problems with speaking decreased by 0.028 with MSG compared to NMSG. In addition, compared to NMSG, it was confirmed that MSG reduced chewing discomfort by 0.047, while self-perceived oral health improved by 0.0123. Finally, as a result of confirming the effect of muscular strength training on oral health and quality of life in Korean adults, there was a significant effect on quality of life despite adjusting for sociodemographic characteristics and oral-health-related factors (p < 0.05).

CONCLUSIONS

In this study, the relationship between muscular strength training and quality of life was confirmed. Therefore, efforts should be made to make oral health management and muscular strength training a part of life in relation to quality of life.

Periodontal Pathogens and Their Links to Neuroinflammation and Neurodegeneration

Pathogens that play a role in the development and progression of periodontitis have gained significant attention due to their implications in the onset of various systemic diseases. Periodontitis is characterized as an inflammatory disease of the gingival tissue that is mainly caused by bacterial pathogens. Among them, Porphyromonas gingivalis, Treponema denticola, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, and Tannerella forsythia are regarded as the main periodontal pathogens. These pathogens elicit the release of cytokines, which in combination with their virulence factors induce chronic systemic inflammation and subsequently impact neural function while also altering the permeability of the blood-brain barrier. The primary objective of this review is to summarize the existing information regarding periodontal pathogens, their virulence factors, and their potential association with neuroinflammation and neurodegenerative diseases. We systematically reviewed longitudinal studies that investigated the association between periodontal disease and the onset of neurodegenerative disorders. Out of the 24 studies examined, 20 showed some degree of positive correlation between periodontal disease and neurodegenerative disorders, with studies focusing on cognitive function demonstrating the most robust effects. Therefore, periodontal pathogens might represent an exciting new approach to develop novel preventive treatments for neurodegenerative diseases.

Edentulism Predicts Cognitive Decline in the US Health and Retirement Cohort Study

This longitudinal cohort study examines if 1) cognitive decline varies by birth cohort, adjusting for covariates, and 2) edentulism and nonuse of dental care predict 10-y cognitive decline (2008-2018). The Health and Retirement Study (HRS) features a representative sample of US adults over age 50. Eligibility criteria included having cognitive interview data available and responding to the question, "Have you lost all of your upper and lower natural permanent teeth?" at 2+ time points between 2006 and 2018. Use of dental care in the past 2 y was assessed. Linear mixed models for repeated measures estimated the trajectories of mean cognition over time for the birth cohorts, adjusted for baseline cognition, dentition status, dental care use, and covariates (demographic characteristics, health behaviors, and medical conditions). Cohort-by-time interaction terms were included to assess if cognitive decline varied by birth cohort. Ten-year change in cognition status (measured by HRS Cogtot27)-categorized as dementia (<7); cognitive impairment, not demented (7-11) 7≤Cogtot27<12; and normal (≥12)-was also investigated according to birth cohort, dentition status, and dental care use. Mean (SD) baseline age was 63.4 (10.1) y (n = 22,728). Older birth cohorts had greater cognitive decline than younger cohorts. Linear mixed-model estimates and 95% confidence intervals for protective factors for cognitive decline included higher baseline cognition (HRS Cogtot27) (0.49; 0.48-0.50), use of dental care in the past 2 y (0.17; 0.10-0.23), and covariates such as greater household wealth and being married. Risk increased with being edentulous (-0.42; -0.56 to -0.28), history of stroke or diabetes, less education, Medicaid recipient, current smoker, loneliness, and poor/fair self-rated health. Edentulism and irregular dental care are among important predictors of cognitive decline. Tooth retention and regular dental care throughout life appear to be important for maintaining oral and cognitive health.

Long-Term Capsaicin Administration Ameliorates the Dysfunction and Astrogliosis of the Brain in Aged Mice with Missing Maxillary Molars

Tooth loss and decreased masticatory function reportedly affect cognitive function; tooth loss allegedly induces astrogliosis and aging of astrocytes in the hippocampus and hypothalamus, which is a response specific to the central nervous system owing to homeostasis in different brain regions. Capsaicin, a component of red peppers, has positive effects on brain disorders in mice. Decreased expression of transient receptor potential vanilloid 1, a receptor of capsaicin, is associated with the development of dementia. In this study, we investigated the effect of capsaicin administration in aged mice (C57BL/6N mice) with reduced masticatory function owing to the extraction of maxillary molars to investigate preventive/therapeutic methods for cognitive decline attributed to age-related masticatory function loss. The results demonstrated that mice with impaired masticatory function showed decreased motor and cognitive function at the behavioral level. At the genetic level, neuroinflammation, microglial activity, and astrogliosis, such as increased glial fibrillary acidic protein levels, were observed in the mouse brain. The mice with extracted molars fed on a diet containing capsaicin for 3 months demonstrated improved behavioral levels and astrogliosis, which suggest that capsaicin is useful in maintaining brain function in cases of poor oral function and prosthetic difficulties.

[Association between oral health and cognitive decline in older Chileans]

OBJECTIVE

To identify the association between oral health and suspected cognitive impairment in older adults in Chile.

METHOD

Cross-sectional study including 1826 people ≥60 years who participated in the National Health Survey of Chile, 2016-2017. Oral health was evaluated by the number of teeth, presence of caries, use of dental prostheses, self-reported oral health, and pain and/or discomfort in the oral cavity. Cognitive impairment was assessed using the Mini-Mental State Examination (MMSE). The association was evaluated by logistic and linear regression, adjusted for sociodemographic and lifestyle variables.

RESULTS

Compared with people without suspicion of cognitive impairment, people with suspected impairment had five fewer teeth (13.4 vs. 8.5 teeth), a much higher difference in women than in men, and a higher frequency of oral pain. Edentulism and fewer teeth were associated with a higher likelihood of suspected cognitive impairment, associations that were not maintained in adjusted models. Oral pain was associated with a higher likelihood of suspected impairment even in the most adjusted model (odds ratio: 1.99; 95% confidence interval [95%CI]: 1.09-3.63). In linear models, an increase of 2% (95%CI: 0.01-0.05) in the MMSE score was observed for each additional tooth.

CONCLUSIONS

Poor oral health, particularly tooth loss and the presence of pain, was associated with cognitive impairment in older adults in Chile.

Innovations in Geriatric Oral Health Care

Older adults are retaining their teeth and need strategies for a lifetime of oral health care. Daily prevention and professional preventive care have the most significant impacts on reducing oral disease in the aging population. Providers of oral health care extend beyond traditional dental professionals to include caregivers and health care providers through teledentistry and interprofessional collaboration. Dental and aging organizations advocate for the inclusion of a dental benefit in Medicare to address access to care. Innovations in geriatric oral health care involve advances in clinical oral health care, delivery and models of care, funding, research, education, and policy.

Updating The General Practitioner on The Association Between Teeth Loss and Temporomandibular Disorders: A Systematic Review

The belief about a possible association between the absence of one or more teeth and the presence of temporomandibular disorders (TMD), although old, is still present among the dental class. Although evidence points to a lack of association between loss of posterior support and the presence of TMD, we do not have critical studies on the extent, quantity, or location of these losses. In this sense, this systematic review aims to investigate the association between tooth loss and the presence of TMD signs or diagnostic subgroups. Search strategies using a combination of keywords tooth loss and TMDs were performed in six databases (PubMed, Embase, Web of Science, Livivo, Lilacs, and Scopus) and gray literature from August to September 2020. Observational studies that investigated the association between tooth loss in TMD were considered. The risk of bias was assessed using the Joanna Briggs Institute (JBI) Critical Assessment Checklist for cross-sectional analytical studies, case-control, and cohort studies. Finally, the level of certainty measured by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was assessed. Six articles were included in the review according to the eligibility criteria. Of these, five had a high risk of bias and one had a moderate risk. Only one study showed an association between the loss of posterior teeth and the presence of joint sounds and joint pain, the others found no significant association with sign or TMD subgroups diagnostic.There is no scientific evidence to support the association between one or more tooth loss and the presence of TMD signs and symptoms or diagnostic subgroups.

International Delphi Study to Optimize the Oral Health Section in interRAI

Introduction: The oral health (OH) of care-dependent older people is generally poor. Since caregivers are mainly responsible for older people's daily care, they can be considered important intermediaries to improve their OH by performing regular OH assessments. The interRAI instruments are introduced in 37 countries to assess care needs and facilitate care planning across different health care settings. The oral health section (OHS) within the interRAI instrument used in long-term care facilities was optimized for the Belgian context to identify residents who need assistance with daily oral care and/or need to be referred to a dentist. This Delphi study evaluated whether the OHS is also relevant and useful in other countries and modified the OHS accordingly until an international consensus was reached. Participants were experts in OH for older people. During 2 rounds of online questionnaires, experts rated the content, assessment process, triggering of Clinical Assessment Protocols, and accompanying guidelines and instruction videos of the optimized OHS. Based on the experts' comments and suggestions collected during the first round, the OHS was adjusted and presented to the experts in the second round for re-evaluation. The first and second questionnaires were completed by 48 and 42 oral health experts from 29 and 27 countries where the interRAI instruments are introduced, respectively. Five experts from 5 countries where interRAI is not introduced also participated in both rounds. After the second round, a consensus of over 86% was reached on all criteria. International consensus on the OHS was reached, considering national and cultural differences that may affect OH. The next step in this research is to evaluate the assessment process to identify potential barriers and facilitators to achieving reliable OH assessments internationally. Furthermore, the effect of the OHS at the level of the resident and of the caregivers will be evaluated.

Tooth loss and the risk of cognitive decline and dementia: A meta-analysis of cohort studies

Introduction

Epidemiological studies have shown that tooth loss may be associated with an increased risk of cognitive decline and dementia. However, some results do not show a significant association. Therefore, we performed a meta-analysis to evaluate this association.

Methods

Relevant cohort studies were searched in PubMed, Embase, Web of Science (up to May 2022), and the reference lists of retrieved articles. The pooled relative risk (RR) and 95% confidence intervals were computed using a random-effects model (CI). Heterogeneity was evaluated using the I ² statistic. Publication bias was evaluated using the Begg's and Egger's tests.

Results

Eighteen cohort studies met the inclusion criteria. Original studies with 356,297 participants with an average follow-up of 8.6 years (ranging from 2 to 20 years) were included in this study. The pooled RRs of tooth loss on dementia and cognitive decline were 1.15 (95% CI: 1.10-1.20; P < 0.01, I ² = 67.4%) and 1.20 (95% CI: 1.14-1.26; P = 0.04, I ² = 42.3%), respectively. The results of the subgroup analysis showed an increased association between tooth loss and Alzheimer's disease (AD) (RR = 1.12, 95% CI: 1.02-1.23) and vascular dementia (VaD) (RR = 1.25, 95% CI: 1.06-1.47). The results of the subgroup analysis also showed that pooled RRs varied by geographic location, sex, use of dentures, number of teeth or edentulous status, dental assessment, and follow-up duration. None of the Begg's and Egger's tests or funnel plots showed evidence of publication bias.

Discussion

Tooth loss is associated with a significantly increased risk of cognitive decline and dementia, suggesting that adequate natural teeth are important for cognitive function in older adults. The likely mechanisms mostly suggested include nutrition, inflammation, and neural feedback, especially deficiency of several nutrients like vitamin D.

How the Loss of Second Molars Corresponds with the Presence of Adjacent Third Molars in Chinese Adults: A Retrospective Study

Third molars (M3s) can increase the pathological risks of neighboring second molars (M2s). However, whether the M3 presence affects M2 loss remains unknown. This retrospective study aimed to reveal the reasons for M2 loss and how M2 loss relates to neighboring M3s. The medical records and radiographic images of patients with removed M2(s) were reviewed to analyze why the teeth were extracted and if those reasons were related to adjacent M3s. Ultimately, 800 patients with 908 removed M2s were included. In the included quadrants, 526 quadrants with M3s were termed the M3 (+) group, and the other 382 quadrants without M3s were termed the M3 (−) group. The average age of patients in the M3 (+) group was 52.4 ± 14.8 years and that of the M3 (−) group was 56.7 ± 14.9 years, and the difference between the two groups was statistically significant (p < 0.001). Of the 908 M2s, 433 (47.7%) were removed due to caries and sequelae and 300 (33.0%) were removed due to periodontal diseases. Meanwhile, 14.4% of the M2s with adjacent M3s were removed due to distal caries and periodontitis, which were closely related to the neighboring M3s; this percentage was much lower when M3 were absent (1.8%). Additionally, 42.2% of M3s were removed simultaneously with neighboring M2s. The presence of M3s, regardless of impaction status, was associated with an earlier loss of their neighboring M2s.

Risk of dementia according to the severity of chronic periodontitis in Korea: a nationwide retrospective cohort study

OBJECTIVES

We investigated the risk of dementia in older adults with chronic periodontitis according to the severity of periodontitis.

METHODS

Data on patients with chronic periodontitis were extracted from the National Health Insurance Service-Senior cohort database from 2002 to 2014. Among 52,728 subjects eligible for inclusion, 11,953 subjects had newly diagnosed mild chronic periodontitis (MCP), and 40,775 subjects had newly diagnosed severe chronic periodontitis (SCP). Two 1:1 propensity score matched cohorts were created with 8,624 patients each in the MCP and SCP groups. To analyze the risk of dementia, a Cox proportional-hazard model was used to calculate hazard ratios with 95% confidence intervals (CIs).

RESULTS

In the Kaplan-Meier curve, the disease-free probability was significantly lower in the SCP group than in the MCP group (p for log-rank=0.001). In the multivariable-adjusted model, the HR for the occurrence of dementia in the SCP group compared to the MCP group was 1.15 (95% CI, 1.04 to 1.27; p=0.009). A subgroup analysis revealed a significant association between dementia and the severity of periodontitis, especially in subjects who were male, aged ≥70 years, and had comorbidities.

CONCLUSIONS

Reducing the severity of chronic periodontitis can help to reduce the risk of dementia. Therefore, it is necessary to aggressively conduct early dementia-prevention programs for males under the age of 70 that include dental health to prevent the progression of periodontitis from mild to severe.

Association of pentosidine and homocysteine levels with number of teeth present in Japanese postmenopausal women

INTRODUCTION

Little is known about whether substances inducing tissue protein degeneration in the oral cavity are associated with the number of teeth present in postmenopausal women. We sought to investigate the association of urinary pentosidine and serum homocysteine levels with the number of teeth and subsequent tooth loss in Japanese postmenopausal women.

MATERIALS AND METHODS

Among participants in the Nagano Cohort Study, 785 postmenopausal women (mean age, 68.1 years) participated in the present study. The number of teeth was re-counted at the time of follow-up in 610 women. Poisson regression analysis was used to investigate differences in the number of teeth among quartiles of pentosidine or homocysteine, adjusting for covariates that correlated with the number of teeth. A Cox proportional hazard model was used to evaluate the association of subsequent tooth loss with pentosidine or homocysteine levels.

RESULTS

Pentosidine quartiles were not associated with the number of teeth at baseline. Participants in the highest homocysteine quartile had significantly fewer teeth at baseline than those in the third and lowest quartiles (p < 0.001 for both). Those in the second quartile had fewer teeth than those in the third (p = 0.001) and lowest (p < 0.001) quartiles. An increased risk of tooth loss during follow-up was significantly associated with higher urinary pentosidine (hazard ratio = 1.073 for 10 pmol/mgCre; p = 0.001).

CONCLUSION

Postmenopausal women with higher homocysteine levels had fewer teeth at baseline. A higher pentosidine concentration increased the risk of subsequent tooth loss. High pentosidine or homocysteine concentrations may be associated with tooth loss in postmenopausal women.

The Impact of Masticatory Function on Cognitive Impairment in Older Patients: A Population-Based Matched Case-Control Study

PURPOSE

The aim of this study was to investigate the association between the changes in masticatory function and cognitive impairment by analyzing longitudinal data of older Korean patients.

MATERIALS AND METHODS

Patients aged over 60 years with dental records between 2005 to 2010 (baseline; T1) and 2014 to 2020 (follow-up; T2) were selected in a single medical center. Based on the dementia diagnosis after T2, the cohort was classified into two groups, the dementia group (n=122) and the control group (n=366). Changes in masticatory function were calculated using the total functional tooth unit (T-FTU) in both groups. The incidence of tooth extraction (%) and the subsequent rehabilitation during the observation period were also evaluated.

RESULTS

In the dementia group, T-FTU significantly decreased from T1 to T2 (9.81±2.78 to 9.11±3.16, respectively, p=0.008), while no significant change was observed in the control group. During the mean observation period of 9 years, significantly more teeth were extracted and neglected to be prosthetically restored in the dementia group than in the control group. Regression analysis revealed that the number of missing teeth neglected [odds ratio (OR)=1.195, 95% confidence interval (CI)=1.025-1.393, p=0.023] and previous alcohol consumption (OR=4.445, 95% CI=1.831-1.795, p=0.001) were the most significant risk factors of dementia.

CONCLUSION

There might be a causative relationship between the neglected missing dentition and the onset of dementia.

Factors affecting provision of oral health care for people with special health care needs: A systematic review

Background

Special health care needs (SHCNs) individuals experience higher levels of dental problems including accessing oral health (OH) facilities. Improving standard of OH care in SHCNs requires identifying barriers and enablers. The aim of this study was to perform a systematic review of prior researches to identify OH care barriers and enablers for SHCN individuals.

Methods

Electronic searching was conducted systematically in PubMed and Cochrane databases. The PICOS parameters were formulated for the inclusion of studies, and the PRISMA method was used to select the articles. Two reviewers independently screened the articles for eligibility and to minimise the risk of bias in the studies and also searched the contents of key articles, quality of methodology, outcomes and reference lists of all the studies included.

Results

A total of 1316 (PubMed 956, Cochrane 360) studies were found initially and after title and abstract screening and also removal of duplication, reviewers selected 53 papers from PubMED and 19 articles from Cochrane to go through full articles and led to the final confirmation of 21 studies. Common challenges included lack of OH knowledge and awareness, difficulty in accessing treatment, transportation problem, treatment cost, and lack of inter-professional collaboration for specialized services. Potential solutions included OHE training and services for patients and caregivers, easy access to dental services, specialized dental practitioners and use of a combination of expertise to meet the demands of SHCN individuals.

Conclusion

This brief analysis will establish dental obstacles to the provision of information to policymakers for SHCN population at organizational, individuals and policy levels. It will help in effective planning for providing and improving OH care quality in caregivers.

The Sedentary Lifestyle and Masticatory Dysfunction: Time to Review the Contribution to Age-Associated Cognitive Decline and Astrocyte Morphotypes in the Dentate Gyrus

As aging and cognitive decline progresses, the impact of a sedentary lifestyle on the appearance of environment-dependent cellular morphologies in the brain becomes more apparent. Sedentary living is also associated with poor oral health, which is known to correlate with the rate of cognitive decline. Here, we will review the evidence for the interplay between mastication and environmental enrichment and assess the impact of each on the structure of the brain. In previous studies, we explored the relationship between behavior and the morphological features of dentate gyrus glial fibrillary acidic protein (GFAP)-positive astrocytes during aging in contrasting environments and in the context of induced masticatory dysfunction. Hierarchical cluster and discriminant analysis of GFAP-positive astrocytes from the dentate gyrus molecular layer revealed that the proportion of AST1 (astrocyte arbors with greater complexity phenotype) and AST2 (lower complexity) are differentially affected by environment, aging and masticatory dysfunction, but the relationship is not straightforward. Here we re-evaluated our previous reconstructions by comparing dorsal and ventral astrocyte morphologies in the dentate gyrus, and we found that morphological complexity was the variable that contributed most to cluster formation across the experimental groups. In general, reducing masticatory activity increases astrocyte morphological complexity, and the effect is most marked in the ventral dentate gyrus, whereas the effect of environment was more marked in the dorsal dentate gyrus. All morphotypes retained their basic structural organization in intact tissue, suggesting that they are subtypes with a non-proliferative astrocyte profile. In summary, the increased complexity of astrocytes in situations where neuronal loss and behavioral deficits are present is counterintuitive, but highlights the need to better understand the role of the astrocyte in these conditions.

Regular dental visits, periodontitis, tooth loss, and atherosclerosis: The Ohasama study

Objective

We aimed to explore the association between regular dental visits and atherosclerosis and between periodontitis, number of remaining teeth, and atherosclerosis among community dwellers in Japan.

Background

Few studies have examined the association between regular dental visits, periodontitis, tooth loss, and atherosclerosis in community dwellers in Japan.

Methods

The participants of this cross‐sectional study included community dwellers aged ≥55 years and residing in Ohasama. Exposure variables were regular dental visits; periodontitis, defined as radiographic alveolar bone loss (BL); the Centers for Disease Control/American Academy of Periodontology (CDC/AAP) classification; and number of remaining teeth. The primary outcome was atherosclerosis, defined as maximum carotid intima‐media thickness ≥1.1 mm or confirmation of atheromatous plaque.

Results

Of 602 participants, 117 had atherosclerosis. In the multivariate model, compared to those with regular dental visits, the odds ratio (OR) (95% confidence intervals [CIs]) of atherosclerosis among those with the absence of regular dental visits was 2.16 (1.03–4.49). Regarding BL‐max, compared with those in the first quartile, ORs (95% CIs) of those in the second, third, and fourth quartiles were 1.15 (0.65–2.30), 0.65 (0.32–1.35), and 1.57 (0.81–3.01), respectively. Regarding CDC/AAP classification, compared to those with no or mild periodontitis, ORs (95% CIs) for those with moderate and severe periodontitis were 2.48 (0.61–10.1) and 4.26 (1.01–17.5), respectively. Regarding the number of remaining teeth, compared to those with ≥20 teeth, ORs (95%CIs) for those with 10–19 and 1–9 teeth were 1.77 (1.004–3.12) and 0.96 (0.52–1.80), respectively.

Conclusion

The absence of regular dental visits and presence of periodontitis are associated with atherosclerosis among community dwellers in Japan.

Cognitive impairment and edentulism among older adults: an observational study using claims data

Background

The scientific link between mastication strength and cognitive function has not yet been strongly corroborated in population studies. Utilizing large-scale claims, we aim to investigate the association between edentulism and cognitive impairment in older American adults.

Methods

Using de-identified claims from a commercial insurer from 2015–2019, we conducted a retrospective cohort study using multilevel regression models to evaluate the association between denture status and clinically diagnosed cognitive impairment. Secondary analysis included symptomatic cognitive impairment in the outcome.

Results

Adjusting for individual-level risk factors, denture status was significantly associated with clinical cognitive impairment with odds ratios of 1.13 (95%CI: 1.02–1.25) and 1.26, (95%CI: 1.09–1.45) for complete dentures on one or both jaws, respectively. Including symptomatic cognitive impairment in the analysis did not substantially change our fundamental findings.

Conclusion

Prevention and treatment of oral diseases should be considered a key component in preserving the overall wellness of older adults.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-02985-w.

A prospective association between tooth status and cognitive performance among older adults in Europe

OBJECTIVES

This study set out to examine both the longitudinal association between tooth status and cognitive performance among older adults in Europe, and the mediating effects of loneliness and quality of life on this association.

METHODS

We conducted a prospective analysis using data from 38,614 participants aged 50 or older, taken from the Survey of Health, Ageing and Retirement in Europe (SHARE) of 2013 (baseline) and 2015 (follow up). Bootstrapping with resampling strategies was used for testing a multiple mediator model.

RESULTS

The average age of participants was 66.9 (SD = 9.4). About 23% of the participants had full sets of their own teeth and 38.2% had missing teeth fully replaced by dental implants or dentures. Participants who had partially replaced teeth (B = 0.038, p < 0.001), and with fully replaced teeth (B = 0.041, p < 0.001), or had all their teeth in place (B = 0.055, p < 0.001), had better cognitive performance compared to those who did not replace their missing teeth. It was also found that quality of life and loneliness partially mediated these relationships - Having all teeth in place or replacing all or partially missing teeth was found to affect cognitive performance also via improved quality of life and through lower loneliness.

CONCLUSION

In later life, poor tooth status can be directly associated with cognitive decline and indirectly linked to cognitive performance, in light of decreasing quality of life and increasing loneliness. Clinicians should be aware of both the impact of poor tooth status on cognitive status and the implications for the wellbeing of older adults.

The Association between Number of Teeth and Cognitive Frailty in Older Adults: A Cross-Sectional Study

OBJECTIVES

This study aimed to explore the association between number of teeth and cognitive frailty in American older adults.

DESIGN

Cross-sectional study.

SETTING

Community.

PARTICIPANTS

The participants were 1,531 community-dwelling older adults aged 60 or older from the NHANES database.

METHODS

Frailty was assessed using a 49-item frailty index, with a cut-off value for frailty of more than 0.21. Cognitive dysfunction was evaluated by the Digit-Symbol Coding Test (DSCT), with the cut-off being below the lowest interquartile range (scores ≤37). Cognitive frailty was defined as participants who suffered from both frailty and cognitive dysfunction. Oral health indicators included number of teeth and other factors, such as the presence of gum disease, daily use of dental floss, daily use of mouthwash and self-rated oral health. Multivariable logistic regression models were used to explore the relationship between number of teeth and cognitive frailty.

RESULTS

The mean age of the total sample was 69.67 (SD=6.60) years, and 52.71% (n=807) were female. Our study suggests there was a negative association between number of teeth and cognitive frailty (OR =0.98,95%CI:0.96-0.99, P=0.044) after controlling for potential confounding factors. In addition, older adults with 20 or more teeth had lower odds of being cognitively frail (OR=0.66,95%CI:0.44-0.99, P=0.046) than individuals who had less than 20 teeth.

CONCLUSION

This study suggests that older adults who have more teeth are associated with a lower risk of cognitive frailty. This finding highlights the importance of maintaining as many teeth as possible throughout life and into old age. Cohort studies will be required in the future to determine this relationship.

What informs oral health and chronic disease policy development in Australia: a citation analysis

Improvement of health services and patient outcomes depends on the translation of health research into health policy. Oral health research can inform policies to manage chronic diseases and improve quality of life of affected individuals. To determine if translation of this research into policy is occurring, we identify where policymakers obtain evidence to inform the development of Australian health policy. We conducted a citation analysis of oral health, cardiovascular disease, diabetes and cognitive impairment National policies to determine if current oral health research has informed oral health and chronic disease policy. We analysed five National policies with 268 individual references to policy or organizational documents (n = 179), peer-reviewed research (n = 74), grey literature (n = 12), or unidentifiable (n = 3). Although we found oral health references listed in the National policies (92), we did not find this information to have been translated into the oral health and chronic disease policies we analysed.

Association between teeth loss and nasogastric tube feeding dependency in older adults from Taiwan: a retrospective cohort study

Background

To examine the association between teeth loss and nasogastric tube feeding dependency in older people.

Methods

The National Health Interview Survey (NHIS) 2005, 2009, and 2013 in Taiwan. Participants were selected by a multistage stratified sampling method and baseline characteristics, including socioeconomic status and health habits, were obtained by well-trained interviewers. The NHIS was linked with the National Health Insurance research database 2000–2016 and the National Deaths Dataset, which contains all the medical information of ambulatory and inpatient care. Cox regression was used to examine the association between the number of teeth lost and nasogastric tube feeding dependency.

Results

There were 6165 adults older than 65 years old enrolled in the analysis, with 2959 male (48%) and the mean (SD) age was 73.95(6.46) years old. The mean follow-up duration was 6.5(3.3) years. Regarding the teeth loss categories, 1660 (26.93%), 2123 (34.44%), and 2382 (38.64%) of participants were categorized as having no teeth loss, loss of 1–9 teeth, and loss of 10–28 teeth, respectively. During 39,962 person-years of follow-up, new-onset nasogastric feeding dependency was recognized in 220(13.25%), 256(12.06%), and 461(19.35%) participants who were categorized as having no teeth loss, loss of 1–9 teeth, and loss of 10–28 teeth, respectively. Kaplan-Meier curves demonstrated significant findings (Log-rank P < 0.01). After potential confounders were adjusted, compared with those without teeth loss, older adults who had lost 10–28 teeth had significantly increased risks of occurrence nasogastric feeding dependency (AHR, 1.31; 95% CI, 1.05–1.62; p-value = 0.02). Furthermore, a significant dose-response relation between the number of teeth lost and increased risk of nasogastric feeding was found (p for trend< 0.01).

Conclusions

Older adults who had lost 10–28 teeth had a significantly increased risk of nasogastric tube feeding dependency. Early identification of the oral disease is crucial for the prevention of the occurrence of teeth loss and the following nutrition problems, which would reduce risk of nasogastric tube feeding dependency.

Dose-Response Meta-Analysis on Tooth Loss With the Risk of Cognitive Impairment and Dementia

OBJECTIVES

To quantify the dose-response associations between tooth loss and risk of cognitive impairment and dementia.

DESIGN

Longitudinal studies that examined the association between tooth loss and cognitive function were systematically searched on 6 databases through March 1, 2020. The study adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines. Risk estimates were pooled using random-effects models. The dose-response associations were assessed using generalized least squares spline models.

SETTING AND PARTICIPANTS

Adults from community, institution, outpatient or in-hospital were included in the meta-analysis.

MEASURES

Cognitive impairment and dementia were defined by neuropsychological tests, diagnostic criteria, or medical records. Tooth loss was self-reported or assessed by clinical examinations.

RESULTS

Fourteen studies were entered into the meta-analysis, including 34,074 participants and 4689 cases with diminished cognitive function. Participants with more tooth loss had a 1.48 times higher risk of developing cognitive impairment [95% confidence interval (CI) 1.18-1.87] and 1.28 times higher risk of being diagnosed with dementia (95% CI 1.09-1.49); however, the association was nonsignificant for participants using dentures (relative risk = 1.10, 95% CI 0.90-1.11). Eight studies were included in the dose-response analysis, and data supported the use of linear models. Each additional tooth loss was associated with a 0.014 increased relative risk of cognitive impairment and 0.011 elevated relative risks of dementia. Edentulous participants faced a 1.54 times higher risk of cognitive impairment and a 1.40 times higher risk of being diagnosed with dementia.

CONCLUSIONS AND IMPLICATIONS

Moderate-quality evidence suggested tooth loss was independently associated with cognitive impairment and dementia; risk of diminished cognitive function increased with incremental numbers of teeth lost. Furthermore, timely prosthodontic treatment with dentures may reduce the progression of cognitive decline related to tooth loss.

Association between Tooth Loss and Alzheimer's Disease in a Nested Case-Control Study Based on a National Health Screening Cohort

Background: Reports on the possible risks for Alzheimer’s disease (AD) have included tooth loss as a potential risk factor. However, there are few studies addressing the association between tooth loss and AD in a large sample of participants. Accordingly, the objective of the current study was to explore the association of tooth loss with the development of AD in Korean adults. Methods: This nested case–control study, which is an analysis utilizing the data of the Korean National Health Insurance Service Health Screening Cohort study, randomly selected AD and control participants among Korean residents aged ≥60 years. The association between the number of missing teeth and AD occurrence was examined using a logistic regression model. Participants’ lifestyle factors (smoking and alcohol consumption) and various medical conditions and comorbidities were included as covariates. Results: The mean number of missing teeth was 2.94 in the AD group and 2.59 in the control group. After adjusting for covariates, tooth loss was significantly associated with AD, with an odds ratio (OR) (per 16 missing teeth) of 1.15 (95% confidence interval (CI) = 1.07–1.23, p < 0.001). Conclusions: Tooth loss remained consistently significantly associated with an increased risk of AD for both upper and lower tooth loss. A higher number of missing teeth was related to a higher probability of AD occurrence in an elderly Korean population. Efforts to manage tooth loss could be a possible approach to prevent AD.

Lack of occlusal support did not impact amyloid β deposition in APP knock-in mice

PURPOSE

The lack of occlusal support is an epidemiological risk factor linked to Alzheimer's disease. This study sought to assess the relationship between amyloid β (Aβ) deposition and the lack of occlusal support in amyloid precursor protein (APP) knock-in mice.

METHODS

Sixteen experimental animals were divided into two groups. The upper molars were extracted in the extraction group (group E), and a sham operation was performed in the control group (group C). The Morris water maze test was performed 4 months after the tooth extraction. Aβ immunohistochemical staining and Nissl staining of the hippocampus were performed. Hippocampal plasma corticosterone and Aβ protein levels were measured.

RESULTS

In the maze task, the escape latency was significantly longer in group E than in group C. In the probe trials, the time elapsed in the target quadrant was significantly shorter in group E than in group C. The number of hippocampal neurons decreased in group E. There was no significant difference in the plasma corticosterone levels between the two groups, indicating that there was no effect of chronic stress on the behavioral results. Hippocampal Aβ40 and Aβ42 protein levels and Aβ deposition areas by immunohistochemical staining were not significantly different between the two groups.

CONCLUSIONS

Aβ deposition was not increased in the hippocampus of molarless APP knock-in mice. As such, it appears that cognitive impairment due to a lack of occlusal support was not related to Aβ deposition.

Oral health-related quality of life is associated with the prevalence and development of depressive symptoms in older Japanese individuals: The Ohasama Study

OBJECTIVE

This prospective study investigated the cross-sectional association between impaired oral health-related quality of life (OHRQoL) and the prevalence of depressive symptoms, and the longitudinal association between impaired OHRQoL and development of depressive symptoms among older adults.

BACKGROUND

Previous studies have shown a relationship between poor oral health and depression among older adults; however, findings are inconsistent.

MATERIALS AND METHODS

Participants were 669 community-dwelling older Japanese individuals aged≥55 years (mean: 67.8 ± 7.2 years). Data of 296 participants were used for longitudinal analyses. OHRQoL was evaluated using the Oral Impacts on Daily Performances scale. Impaired OHRQoL was defined as the presence of at least one impact on the scale. Depressive symptoms were assessed using the Japanese version of the Zung self-rating depression scale with a cut-off score of 40.

RESULTS

The cross-sectional logistic regression model demonstrated that impaired OHRQoL was significantly associated with depressive symptoms (odds ratio [OR], 5.17; 95% confidence interval [CI], 2.99-8.95) independent of age, sex, body mass index, hypertension, cerebrovascular/cardiovascular disease, smoking, drinking alcohol, education, cognitive function, objective oral health (dentition status) and oral health behaviour (dental visit within 1 year). Similarly, impaired OHRQoL predicted the development of depressive symptoms within 4 years in a fully adjusted longitudinal model (OR, 6.00; 95% CI, 1.38-26.09).

CONCLUSION

Impaired OHRQoL was identified as a potential comorbidity of depressive symptoms and a predictor for depressive disorder later in life. OHRQoL may be a useful clinical outcome for elder patients with regard to their mental and oral health.

Association of Edentulism with Various Chronic Diseases in Mexican Elders 60+ Years: Results of a Population-Based Survey

Objective: To determine the association of edentulism with different chronic diseases and mental disorders in Mexicans aged 60 years and over. Material and Methods: A cross-sectional study was carried out using data from the World Health Survey for Mexico, in a probabilistic, multi-stage cluster sampling framework. Data for self-report of chronic diseases (diabetes, arthritis, angina pectoris and asthma), mental disorders (depression and schizophrenia) and edentulism were analyzed. Edentulism data were available for 20 of the 32 States of Mexico. Statistical analysis was performed in Stata 14.0 using the svy module for complex sampling (Complex nature under which individuals are sampled). Results: In total 4213 subjects were included, representing a population of 7,576,057 individuals. Mean age was 70.13 ± 7.82 years (range 60 to 98); 56.2% were women. Chronic diseases’ prevalence and mental disorders prevalence were as follows: diabetes 15.0% (N = 1,132,693); arthritis 13.2% (N = 1,001,667); depression 5.5% (N = 414,912); angina pectoris 4.5% (344,315); asthma 3.6% (N = 269,287); and schizophrenia 2.2% (N = 16,988). The prevalence of edentulism was 26.3%, which pertained to 1,993,463 people aged 60 years and over. Angina in women aged 60 to 69 years (p < 0.05) and depression in men aged 70 years and over (p < 0.0001) were associated with higher prevalence of edentulism. Conclusions: There was generally sparse association between edentulism on chronic diseases and mental disorders included in the study, except for women aged 60 to 69 years for angina, and in men aged 70 and over, for depression. Although our findings are misaligned with previous reports, longitudinal studies are required to test causal and temporal relationships between edentulism with chronic diseases and mental disorders.

Factors Associated with Denture Non-use in Older Adults Requiring Long-Term Care

BACKGROUND

Evidence suggests that denture non-use is significantly associated with activities of daily living, oral function, and cognitive decline. Few studies have focused on the possibility that the indications for denture use may differ depending on the cognitive and physical functions in older adults requiring long-term care.

OBJECTIVES

The aim of this study was to elucidate the factors associated with denture non-use in older adults requiring long-term care.

METHODS

This cross-sectional study comprised 201 older adults (45 men and 156 women; average age = 86.2 ± 7.1 years) requiring long-term care in Japan. Those who did not require denture treatment were classified by dentists into denture-use and denture non-use groups. The severity of dementia was assessed using the Clinical Dementia Rating scale. Multiple logistic regression analyses were conducted to detect the factors significantly associated with denture non-use.

RESULTS

The proportion of participants without dentures was 58.2%. Multiple logistic regression analyses revealed that a moderate dementia (odds ratio [OR], 4.44; 95% confidence interval [CI] 1.18-16.71, p=0.027) and rinsing ability (OR 3.00; 95% CI 1.12-8.06; p=0.030) were significant factors related to the non-use of dentures.

CONCLUSION

Severity of dementia and rinsing ability were significantly associated with non-use of dentures. These findings indicate the necessity of evaluating oral and cognitive functions while planning denture treatment in older adults requiring long-term care.

Innovations in Geriatric Oral Health Care

Older adults are retaining their teeth and need strategies for a lifetime of oral health care. Daily prevention and professional preventive care have the most significant impacts on reducing oral disease in the aging population. Providers of oral health care extend beyond traditional dental professionals to include caregivers and health care providers through teledentistry and interprofessional collaboration. Dental and aging organizations advocate for the inclusion of a dental benefit in Medicare to address access to care. Innovations in geriatric oral health care involve advances in clinical oral health care, delivery and models of care, funding, research, education, and policy.

Cognitive Performance and Its Associations with Dental Caries: Results from the Dental, Oral, Medical Epidemiological (DOME) Records-Based Nationwide Study

Relatively few studies have analyzed the association between cognitive performance and dental status. This study aimed to analyze the association between cognitive performance and dental caries. Included were data from the dental, oral, medical epidemiological (DOME) study; cross-sectional records-based research, which integrated large socio-demographic, medical, and dental databases of a nationally representative sample of young to middle-aged military personnel (N = 131,927, mean age: 21.8 ± 5.9 years, age range: 18-50). The cognitive function of draftees is routinely measured at age 17 years using a battery of psychometric tests termed general intelligence score (GIS). The mean number of decayed teeth exhibited a gradient trend from the lowest (3.14 ± 3.58) to the highest GIS category (1.45 ± 2.19) (odds ratio (OR) lowest versus highest = 5.36 (5.06-5.68), p < 0.001). A similar trend was noted for the other dental parameters. The associations between GIS and decayed teeth persisted even after adjusting for socio-demographic parameters and health-related habits. The adjustments attenuated the OR but did not eliminate it (OR lowest versus highest = 3.75 (3.38-4.16)). The study demonstrates an association between cognitive performance and caries, independent of the socio-demographic and health-related habits that were analyzed. Better allocation of resources is recommended, focusing on populations with impaired cognitive performance in need of dental care.

Impact of Poor Oral Health on Community-Dwelling Seniors: A Scoping Review

The aim of this scoping review was to determine health-related impacts of poor oral health among community-dwelling seniors. Using MeSH terms and keywords such as elderly, general health, geriatrics, 3 electronic databases-Medline, CINAHL, and Age Line were searched. Title and abstracts were independently screened by 3 reviewers, followed by full-texts review. A total of 131 articles met our inclusion criteria, the majority of these studies were prospective cohort (77%, n = 103), and conducted in Japan (42 %, n = 55). These studies were categorized into 16 general health outcomes, with mortality (24%, n = 34), and mental health disorders (21%, n = 30) being the most common outcomes linked with poor oral health. 90% (n = 120) of the included studies reported that poor oral health in seniors can subsequently lead to a higher risk of poor general health outcomes among this population. Improving access to oral healthcare services for elderly can help not only reduce the burden of oral diseases in this population group but also address the morbidity and mortality associated with other general health diseases and conditions caused due to poor oral health. Findings from this study can help identify shortcomings in existing oral healthcare programs for elderly and develop future programs and services to improve access and utilization of oral care services by elderly.

Association Between Oral Health and the Medical Costs of Dementia: A Longitudinal Study of Older Japanese

OBJECTIVE

Oral health status may be associated with dementia, which in turn results in higher medical costs among older people.

METHODS

This STUDY enrolled 4,275 older individuals. Generalized linear models were constructed with the medical costs of dementia as the dependent variable, and number of teeth, Community Periodontal Index (CPI), and other factors as independent variables.

RESULTS

Individuals with fewer teeth or with poor periodontal condition had significantly higher medical costs ratios for dementia independent of other confounding variables. The adjusted medical costs ratios of dementia were 4.13 (95% CI [confidence interval]; 1.79-9.56) for those with ≤9 teeth compared with those with ≥20 teeth and 3.48 (95% CI; 1.71-7.08) for those with personal CPI code 4 compared with those with personal CPI code 0-2.

CONCLUSIONS

Oral health status was associated with the medical costs of dementia. Preventing tooth loss and maintaining periodontal health may contribute to controlling dementia costs.

Prevalence and Clinical Correlation of Decayed, Missing, and Filled Teeth in Elderly Inpatients With Schizophrenia

Introduction: Schizophrenia is a mental disease with a profound impact on human health. Patients with schizophrenia have poor oral hygiene, increasing their risk of systemic diseases, such as respiratory infections, and declining their quality of life. Therefore, this study aims to assess the oral health status of inpatients with schizophrenia, analyze its related factors, and thus provide scientific evidence for further exploration of corresponding control strategies. Methods: A total of 425 inpatients older than 50 years with a diagnosis of schizophrenia from two psychiatric hospitals (mean age 58.49 ± 5.72 years) were enrolled. The demographic data of the patients were checked on admission. Two independent dentists examined caries, missing teeth, and fillings. Mini-Mental State Examination (MMSE) and Global Deterioration Scale were performed as cognitive tests. Positive and Negative Syndrome Scale and Repeatable Battery for the Assessment of Neuropsychological Status rating scale were used to determine their mental status. Results: The average decayed, missing, and filled teeth index was 12.99 ± 8.86. Linear regression analysis showed that the decayed, missing, and filled teeth index had a significantly positive relationship with age (p < 0.001) and smoking (p < 0.001) and a negative relationship with MMSE (p = 0.029). The missing teeth index had a positive relationship with age (p < 0.001), smoking (p < 0.001), and Global Deterioration Scale (p = 0.014) and a negative relationship with MMSE (p = 0.004). Conclusion: The oral health of elderly patients with schizophrenia is poor, which may be related to the cognitive level of patients and affect their quality of life. The focus should be provided to the oral care of patients with schizophrenia, and investment in their specialized oral treatment should be increased.

Relationship between cerebral atrophy and number of present teeth in elderly individuals with cognitive decline

BACKGROUND AND AIM

Recent shifts in the distribution of Japan's population towards older ages, have meant that the chance of encountering patients with dementia in dental clinics is increasing. Many studies have shown that the brain volume decreases along with the progression of dementia. Although previous studies have reported a relationship between tooth loss or periodontitis and the onset of dementia, the pathological mechanisms underlying this association have not been elucidated. In this study, we aimed to examine the relationship between the oral condition and brain atrophy and to discuss how to adequately deal with patients with dementia.

PARTICIPANTS AND METHODS

This cross-sectional study included 15 participants who underwent brain magnetic resonance imaging (MRI). The participants were 60 years or older and presented with cognitive decline, including Alzheimer's disease (AD) and mild cognitive impairment (MCI), diagnosed by a neurologist. We obtained information on the oral condition, lifestyle, cognitive function, and brain atrophy. Cognitive function was assessed using the Mini-Mental State Examination (MMSE). MR images of each patient were analyzed using the voxel-based specific regional analysis system for Alzheimer's disease (VSRAD) to provide a quantitative measure of the degree of brain atrophy.

RESULTS

The study population included 4 male and 11 female patients. The mean age and mean number of present teeth were 75.9 years (SD 6.7) and 15.0 (SD 11.1), respectively. The median MMSE score was 25.6 (SD 3.7). The degree of atrophy of the whole brain was significantly correlated with the number of present teeth (ρ = -0.72, p < 0.05) and the presence of a daily exercise habit (ρ = -0.66, p < 0.05).

CONCLUSION

This study demonstrated that the number of present teeth could be an indicator of the progress of dementia. Preserving the teeth as well as the acquisition of a regular exercise habit might be important for preventing progression of dementia. Further research examining a larger study population and analyzing a greater number of factors is warranted.

Low Tongue Strength and the Number of Teeth Present Are Associated with Cognitive Decline in Older Japanese Dental Outpatients: A Cross-Sectional Study

To mitigate the impact of dementia, initiating early intervention is important. This study aims to investigate the associations between deterioration in oral function and cognitive decline in older outpatients whose oral health was maintained in the dental clinic. This study included 50 outpatients aged ≥65 years. We used the Japanese version of the Montreal Cognitive Assessment (MoCA-J) to assess cognitive decline. Oral function was evaluated by tongue pressure, masticatory performance, and swallowing ability. A full-mouth periodontal examination was conducted, and the occlusal support and number of teeth were recorded. Odds ratios (ORs) and 95% confidence intervals (CIs) for cognitive decline (MoCA-J score ≤ 25 points) were calculated using logistic regression models. The age, number of teeth, tongue pressure, and masticatory performance were significantly correlated with cognitive decline (p < 0.05). Logistic regression analyses revealed that cognitive decline was independently associated with age (OR: 1.25; 95% CI: 1.03-1.52; p = 0.024), number of teeth (OR = 0.83; 95% CI: 0.76-1.00; p = 0.047), and lower tongue pressure (OR: 0.87; 95% CI: 0.77-0.98; p = 0.022). Lower tongue pressure and a small number of remaining teeth may be associated with cognitive decline in Japanese outpatients.

The Effect and Optimal Dosage of Dexmedetomidine Plus Sufentanil for Postoperative Analgesia in Elderly Patients With Postoperative Delirium and Early Postoperative Cognitive Dysfunction: A Single-Center, Prospective, Randomized, Double-Blind, Controlled Trial

Background

Postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) are common complications after major surgery among elderly patients. Dexmedetomidine (DEX) is less frequently explored for its effects in patients with postoperative neurocognitive disorders. This study investigated the effect and optimal dosage of DEX for patient-controlled analgesia (PCA) on POD and early POCD after major surgery among elderly patients.

Methods

Patients in four groups received continuous infusion of DEX 0, 100, 200, and 400 μg with sufentanil 150 μg for PCA immediately after surgery. POD and POCD were assessed on postoperative days 1, 2, 3, and 7 by using the Confusion Assessment Method (CAM) and Mini-Mental State Examination (MMSE) scales. Furthermore, the incidence of POD and POCD of all the four groups in postoperative 7 days classified by high risk factors (age, education, surgical site, and surgical category), sedation level, postoperative pain intensity, and side effects were assessed.

Results

The overall incidence rates of POD and early POCD 7 days after surgery were lower in the DEX 200 μg 400 μg groups than in the DEX 0 μg and 100 μg groups (P < 0.05). Compared with DEX 200 μg, DEX 400 μg reduced early POCD in patients who underwent open surgery (P < 0.05). There were no intergroup differences in the postoperative sedation level, pain intensity, and side effects.

Conclusion

The continuous infusion of DEX 200 μg or DEX 400 μg in PCA significantly decreased the incidence of POD and early POCD after major surgery without increasing any side effects. Compared with DEX 200 μg, DEX 400 μg was preferred for reducing early POCD in patients who underwent open surgery.