Oral health in patients with dementia: A meta-analysis of comparative and observational studies

Mediating and moderating effects of plasma proteomic biomarkers on the association between poor oral health problems and incident dementia: The UK Biobank study

The plasma proteome can mediate poor oral health problems (POHP)'s link to incident dementia. We screened 37,269 UK Biobank participants 50-74 years old (2006-2010) for prevalent POHP, further tested against 1463 plasma proteins and incident dementia over up to 15 years of follow-up. Total effect (TE) of POHP-dementia through plasma proteomic markers was decomposed into pure indirect effect (PIE), interaction referent (INTREF), controlled direct effect (CDE), or mediated interaction (INTMED). POHP increased the risk of all-cause dementia by 17% (P < 0.05). Growth differentiation factor 15 (GDF15) exhibited the strongest mediating effects (PIE > 0, P < 0.001), explaining 28% the total effect of POHP on dementia, as a pure indirect effect. A first principal component encompassing top 4 mediators (GDF15, IL19, MMP12, and ACVRL1), explained 11% of the POHP-dementia effect as a pure indirect effect. Pathway analysis including all mediators (k = 173 plasma proteins) revealed the involvement of the immune system, signal transduction, metabolism, disease, and gene expression, while STRING analysis indicated that top mediators within the first principal component were also represented in the two largest proteomic clusters. The dominant biological GO pathway for the GDF15 cluster was GO:0007169 labeled as "transmembrane receptor protein tyrosine kinase signaling pathway." Dementia is linked to POHP mediated by GDF15 among several proteomic markers.

DO ORAL CARE AND REHABILITATION IMPROVE COGNITIVE FUNCTION? A SYSTEMATIC REVIEW OF CLINICAL STUDIES

OBJECTIVES

An increasing number of studies have identified an association between oral health status and cognitive function. However, the effect of oral interventions, including oral health care, dental treatment and oral motor exercises, on cognitive function remains unclear. This systematic review examined whether oral interventions contribute to the long-term improvement of cognitive status.

METHODS

Four databases were searched (MEDLINE, Web of Science, Cochrane Library, and ICHUSHI Web) to identify randomized and nonrandomized controlled trial studies and prospective cohort studies from inception until 1 September 2023, published in English or Japanese. The Cochrane risk of bias tool for randomized controlled trials and the risk of bias assessment tool for nonrandomized studies were used to assess bias risk.

RESULTS

A total of 20 articles were included in the qualitative analysis; 13 articles were published in English, and 7 were published in Japanese. The implemented interventions were oral care in 8 studies, dental treatment in 8 studies, and oral motor exercise in 4 studies. One study found a significant effect on attention following oral care intervention. Some dental treatments influenced cognitive function, although a clear positive effect was not determined. In 1 study, attention and working memory improved in the chewing exercise group.

CONCLUSIONS

Several studies verified the improvement effects of oral interventions, such as oral care, dental treatment, and oral motor exercise, on cognitive function or impairment. However, there was still a lack of conclusive evidence that such an intervention clearly improved cognitive function. To clarify the effects of oral interventions on cognitive function, it is necessary to examine participants, interventions, and outcome measures in detail.

Research hotspots and trends of oral health in older adults from 2013 to 2023: A bibliometric and visual analysis

Background

Oral health problems seriously affect the quality of life of older adults. It is of great significance to investigate the statuses of oral health in older adults. The study aimed to analyze the current status, hotspots and frontiers of global oral health research in older adults through bibliometrics to provide references and guidance for future research in this field.

Methods

Literature on oral health in older adults from 2013 to 2023 was retrieved from the Web of Science Core Collection (WoSCC) database. CiteSpace 6.2.R4 was used for bibliometric and visual analysis, including journal and co-cited journal, country/region, institution, author, co-cited references, and keyword analysis.

Results

A total of 1430 publications related to oral health in older adults were included. The number of publications has gradually increased over the past decade. The most widely published and cited journal was Gerodontology. The most prominent contribution came from the United States of America, and the University of London and Hirohiko Hirano were the most prolific institution and author, respectively. The current research hotspots were summarized as oral hygiene interventions, oral health-related quality of life and oral health issues in older adults. Cohort studies of oral health, the relationship between oral health and frailty, and the correlation between oral health and nutritional status may be emerging research trends.

Conclusions

This study systematically analyzed the hotspots and frontiers of oral health in older adults and called for increased collaboration among countries, institutions, and authors. In addition, oral hygiene interventions for older adults, oral health-related quality of life, oral health issues, cohort studies of oral health, and the relationship between oral health and frailty or nutritional status may be the focus of future research.

An umbrella review on the association between factors of oral health and cognitive dysfunction

An increasing number of systematic reviews and meta-analyses have been published on the association between oral health and cognitive dysfunction, also known as oral-cognitive links. However, there is great diversity in the oral and cognitive factors included in these studies, with different opinions for clinical practice drawn from the evidence. To understand which oral and cognitive factors are involved in those associations, we conducted an umbrella review of 28 systematic reviews, including 12 meta-analyses, on oral-cognitive links. We found that (a) periodontal diseases, oral microbiome, and dementia were frequently studied, while other factors, such as mastication and mild cognitive impairment, were less commonly investigated, and (b) severe deterioration of oral health, such as severe periodontitis or extensive tooth loss, rather than the presence of oral diseases alone, was strongly associated with cognitive dysfunction. In conclusion, the diversity of oral and cognitive factors included in the review studies reflects the complexity of oral-cognitive links. Clarifying the factors helps to form evidence-based clinical advice for healthcare.

Advances in the prevention and treatment of Alzheimer's disease based on oral bacteria

With the global population undergoing demographic shift towards aging, the prevalence of Alzheimer's disease (AD), a prominent neurodegenerative disorder that primarily afflicts individuals aged 65 and above, has increased across various geographical regions. This phenomenon is accompanied by a concomitant decline in immune functionality and oral hygiene capacity among the elderly, precipitating compromised oral functionality and an augmented burden of dental plaque. Accordingly, oral afflictions, including dental caries and periodontal disease, manifest with frequency among the geriatric population worldwide. Recent scientific investigations have unveiled the potential role of oral bacteria in instigating both local and systemic chronic inflammation, thereby delineating a putative nexus between oral health and the genesis and progression of AD. They further proposed the oral microbiome as a potentially modifiable risk factor in AD development, although the precise pathological mechanisms and degree of association have yet to be fully elucidated. This review summarizes current research on the relationship between oral bacteria and AD, describing the epidemiological and pathological mechanisms that may potentially link them. The purpose is to enrich early diagnostic approaches by incorporating emerging biomarkers, offering novel insights for clinicians in the early detection of AD. Additionally, it explores the potential of vaccination strategies and guidance for clinical pharmacotherapy. It proposes the development of maintenance measures specifically targeting oral health in older adults and advocates for guiding elderly patients in adopting healthy lifestyle habits, ultimately aiming to indirectly mitigate the progression of AD while promoting oral health in the elderly.

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 oral health and cognitive function among Chinese older adults: the Taizhou imaging study

BACKGROUND

We aimed to investigate the association between oral health and cognitive function in a sample of older adults from a Chinese rural community.

METHODS

The cross-sectional cognitive function of 677 individuals were assessed by Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). A comprehensive profile of the oral health status was evaluated by questionnaire and clinical examination.

RESULTS

Multiple covariates-adjusted regression models demonstrated decayed teeth (DT) and decayed/missing/filled teeth (DMFT) were negatively associated with MoCA score (all p < 0.05). Calculus index (CI) and clinical attachment loss (CAL) were significantly associated with the lower MoCA, short-term memory and executive function score, respectively (all p < 0.05). Additionally, participants with missing teeth unrestored tend to get lower MMSE and MoCA scores (p < 0.05). The results also showed that increased DT and CI were modestly associated with higher odds of cognitive impairment (p < 0.05).

CONCLUSIONS

There is an association between oral health and global cognition. Poor periodontal status was strongly associated with worse global cognition performance, especially in the short-term memory and executive domain for the aging population.

Interventions to Improve the Oral Hygiene of Individuals with Alzheimer's Disease: A Systematic Review

This systematic review evaluates published evidence on oral hygiene interventions conducted in Alzheimer’s disease (AD) patients. PubMed, Embase, Cochrane Library, CINAHL, Dentistry & Oral Sciences Source, and Web of Science were searched for articles published up to 19 April 2021. The main outcomes of interest were the Plaque index score (PI), oral health knowledge of participants or their caregivers, and behaviors and attitudes towards oral hygiene. Study quality was assessed using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies of the National Institutes of Health. The study was conducted under PROSPERO registration code CRD42021247733. Two studies met the inclusion criteria. One was a pre-post study conducted in Brazil, and the other was a prospective cohort study carried out in China. The sample sizes of these studies were 29 and 168, respectively. Both studies were carried out in institutionalized patients and presented a significant loss to follow-up. The PI and gingival index scores both improved after the application of the respective interventions, yet the differing methodologies used precluded further comparisons. The studies were deemed to be of good and regular quality, respectively. Despite the need for more comprehensive interventions to ensure a better oral health status and a higher quality of life for AD patients, an alarming lack of studies have been conducted in this population.

Analysis of changes and trends in the use of sedatives in dental sedation using data from the National Health Insurance in Korea

Background

Although dental sedation helps control anxiety and pain, side effects and serious complications related to sedation are gradually increasing. Due to the introduction of new drugs and sedation methods, insurance rates, legal regulations, drugs, and methods used for dental sedation are inevitably changed. In the Republic of Korea, National Health Insurance is applied to all citizens, and this study investigated changes in the use of sedatives using this big data.

Methods

This study used customized health information data provided by the Healthcare Insurance Review & Assessment Service of Korea. Among patients with a record of use of at least one of eight types of sedatives for dental sedation between January 2007 and September 2019 were selected; the data of their overall insurance claims for dental treatment were then analyzed.

Results

The number of patients who received dental sedation was 786,003, and the number of dental sedation cases was 1,649,688. Inhalational sedation using nitrous oxide (N₂O) accounted for 86.8% of all sedatives that could be claimed for drugs and treatment. In particular, it was confirmed that the number of requests for sedation using N₂O sharply increased each year. Midazolam showed an increasing trend, and in the case of chloral hydrate, it gradually decreased.

Conclusion

According to our analysis, the use of N₂O and midazolam gradually increased, while the use of chloral hydrate gradually decreased.

Behaviors of care providers and resistiveness to oral care of persons living with dementia

Since care providers' behavior could be related to resistiveness to care (RTC) among persons living with dementia, developing care providers' behavioral strategies to reduce or prevent RTC is required. This study examined whether care providers' person-centered or task-centered behaviors were related to RTC. A secondary data analysis was conducted using 70 videos of 23 persons living with dementia who received routine oral care in long-term care settings. Data were analyzed using linear mixed models. Among task-centered behaviors, "physically controlling" significantly increased RTC. For person-centered behaviors, "cooperatively negotiating" increased RTC, while "assessing comfort" decreased RTC. Care providers need to consider the comfort or needs of persons living with dementia rather than physically controlling them in oral care situations. These findings may offer insight into the context of RTC occurrences to provide more comfortable oral care for persons living with dementia.