Evidence summary: the relationship between oral health and dementia

"Chew on This: Oral health is associated with cognitive function among Canadians enrolled in the Canadian Longitudinal Study on Aging"

OBJECTIVES

Life expectancy has increased globally, leading to a higher proportion of older adults, particularly in developed countries like Canada. This demographic shift strains healthcare systems and is associated with an increased risk of dementia, a condition characterised by cognitive decline. Oral health has emerged as a potential modifiable risk factor for dementia, yet the evidence remains conflicting. This study examines the association between oral health parameters and cognitive functioning in the Canadian population, utilizing data from the Canadian Longitudinal Study on Aging (CLSA).

METHODS

A cross-sectional analysis was conducted using baseline data from the comprehensive cohort of the CLSA, comprising 30,097 participants aged 45-85 years. Oral health was assessed via self-reported oral health (SROH) and masticatory ability (MA). Cognitive function was evaluated using a battery of neuropsychological tests, and a Cognitive Impairment Indicator (CII) was derived. Logistic regression models were employed to examine the association between oral health and cognitive impairment, adjusting for confounders.

RESULTS

We found that poor SROH was not significantly associated with cognitive impairment (OR = 1.19, 95 % CI = 0.63-2.09), while inadequate MA was significantly associated with higher odds of cognitive impairment (OR = 2.82, 95 % CI = 1.82-4.25).

CONCLUSION

The findings suggest a significant association between perceived MA and cognitive impairment within this cohort.. These results suggest that perceived ability to chew could be a potentially modifiable risk factor for cognitive decline. Further research is warranted to explore the mechanisms underlying these associations and to develop targeted preventive strategies.

CLINICAL SIGNIFICANCE

This paper highlights that middle aged and elderly Canadians with inadequate MA have a 2.82 times higher odds of experiencing cognitive impairment. Addressing chewing difficulties may serve as a modifiable risk factor for early cognitive decline, offering a potential window of opportunity to slow down the process of cognitive decline among aging populations.

Healthcare utilization among Japanese older adults during later stage of prolonged pandemic

This study examines healthcare utilization patterns among Japan's older population (aged 75 and above) during a prolonged public health emergency, focusing on the later phase of the COVID-19 pandemic (November 2021-September 2022). This period was characterized by the Omicron variant, widespread vaccination coverage, and adapted public health measures. Using a comprehensive dataset of 189,841,257 medical claims linked with income tax records, we analyze how healthcare utilization correlates with public health measures, pandemic severity, and income levels. Our findings reveal distinct utilization patterns: moderate decreases in healthcare visits during periods of public health measures, with the association between pandemic severity and healthcare use varying based on whether these measures are in place. Despite fluctuations in visit frequency, healthcare costs remain stable, indicating consistent service intensity. While income-related differences in general healthcare access are modest, dental care shows more pronounced socioeconomic variations. These patterns suggest a transition from initial widespread healthcare avoidance to more stable healthcare engagement, indicating adaptation to prolonged crisis conditions. Our findings provide insights for maintaining healthcare access during extended public health emergencies, particularly in aging societies where balancing healthcare needs with public health measures is crucial.

Disadvantage starts early: academy football has high levels of oral disease

ABSTRACT

Objectives

We have previously reported high levels of oral disease in professional senior team footballers in England and Wales. In this study, we aimed to determine the prevalence of oral disease in professional academy footballers, to identify if problems start earlier and to inform health promotion strategies.

Method

Professional academy football clubs in England (footballers aged 16-18 years) were invited to participate. Questionnaires were used to collect oral health behaviours and self-reported impacts and validated clinical outcomes to assess oral health.

Results

160 academy footballers were recruited from 10 English academy football clubs, of whom 86.8% (n=139) were men and 13.2% (n=21) were women, with a median age of 16.9 years. We identified high levels of oral disease: 31.2% (n=50) had dental caries requiring treatment; 76.8% (n=123) had gingivitis; and 22.5% (n=36) had periodontitis. Tooth wear affecting up to at least 50% of tooth structure was present in 15.5% (n=25) of participants. While 76.2% (n=122) self-reported brushing their teeth twice a day, 15.5% (n=25) brushed once or less a day and 21% (n=34) had not attended the dentist for >2 years. There was a general perception that oral health issues impacted the sporting performance of participants.

Conclusion

In this study, the prevalence of oral diseases among professional academy footballers in England was high and greater than found in national surveys of a similar age demographic. Urgent action is needed to embed oral health promotion in development and youth football, to reverse and prevent the disadvantages that will have lifelong consequences for treatment burden, quality of life and sporting performance.

Social workers' consideration of dental support for people living with dementia: Findings from interviews and care assessment documentation

Social work assessments underpin support plans for many people living with dementia in their own homes in England, but it is unclear how they acknowledge that dementia places people at greater risk of mouth and dental problems affecting their wellbeing. We explored if and how dental needs are addressed during care assessments and social workers' perceptions of this aspect of personal care. This study analysed (a) semi-structured interviews with 14 social workers providing support to people living with dementia in their own homes, (b) data from 39 care assessments and support plans from two English local authorities. Interviews were recorded online, transcribed, and thematically analysed. Documents were analysed descriptively and presented visually. Participants acknowledged that oral care may be overlooked during assessments and reflected on various reasons, including assumptions of responsibility and role restrictions, limited training, and poor links with dental services. This was further evident in the analysis of assessment documentation. Participants identified potential strategies and practice changes to better integrate oral care in social work practice. These included increased awareness and more discussions around dental needs, skills training and streamlining of support. The findings have implications for social workers, educators, and commissioners or funders engaging with people affected by dementia in social work and beyond.

ORAL CARE AND DENTAL INTERVENTIONS SHOW MIXED AND UNCLEAR EFFECTS ON COGNITIVE FUNCTION

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION

DO ORAL CARE AND REHABILITATION IMPROVE COGNITIVE FUNCTION? A SYSTEMATIC REVIEW OF CLINICAL STUDIES Inamochi Y, Ogino Y, Harada K, Fueki K, Ayukawa Y, Nishimura M, Maekawa K, Kang Y, Hirai T, Kuboki T. DO ORAL CARE AND REHABILITATION IMPROVE COGNITIVE FUNCTION? A SYSTEMATIC REVIEW OF CLINICAL STUDIES. J Evid Based Dent Pract. 2024 Mar;24(1):101948. 10.1016/j.jebdp.2023.101948. Epub 2023 Oct 19. PMID: 38448117.

SOURCE OF FUNDING

None.

TYPE OF STUDY/DESIGN

Systematic review.

Longitudinal association between posterior occlusal contact and dementia development in a large retrospective cohort study using a Japanese claims database

This study examines the association between posterior occlusal contact and the risk of dementia development in the Japanese population, utilizing Eichner classification to evaluate occlusal status. Data from Japanese health insurance claims were analyzed for the period from April 2016 to March 2022. Participants had undergone specific health checkups, had no prior history of dementia, and were classified according to their dental occlusal contact. Dementia diagnoses were determined using ICD-10 codes, and participants were divided into three groups-A, B, and C-based on the Eichner classification, which indicates the extent of occlusal contact. Over an average follow-up period of 35.6 months, 691 dementia were identified among 931,309 participants. Those diagnosed with dementia were more likely to belong to Eichner B and C groups, signifying reduced occlusal contact. After adjusting for covariates, the hazard ratios (95% confidence intervals) for Eichner B and C were 1.73 (1.31-2.28) and 2.10 (1.35-3.26), respectively. Sensitivity analyses confirmed these findings in adults aged 60-75. These findings suggest that reduced posterior occlusal contact correlates with an increased risk of dementia. Since the study is limited to participants under the age of 75, further research is required to determine its generalizability to older populations.

A feasibility study to recruit, retain and treat periodontitis in volunteers with mild dementia, whilst monitoring their cognition

OBJECTIVES

Dementia patients are challenging to manage dentally. This study determined whether individuals with mild dementia and periodontitis, could be recruited, retained and demonstrate sustained oral health improvements over 2 years following personalised professional periodontitis treatment. The feasibility of same visit cognition measurements was assessed.

METHODS

A non-randomised study in individuals with mild dementia, capacity to consent, periodontitis and ≥6 teeth. Following enrolment and dental/cognitive assessments, personalised periodontal treatment, followed by 3-monthly supportive periodontal care was performed. Cognitive and periodontal assessments were undertaken at 6, 12, 24-months. Participants and project-partners fed back on homecare regimens.

RESULTS

18 participants were recruited, 15 completed 12- & 8 completed 24-months, 1 participant failed to attend one appointment, and early study termination due to COVID19. From baseline to 12-months mean percentage bleeding sites, Turesky plaque score ≥2 and periodontal pockets ≥4 mm decreased significantly (34.4 vs 14.75, p < 0.01; 78.49 vs 57.5, p < 0.01; 18.38 vs 5.14, p < 0.001). Significant change from baseline was retained at 24-months for mean percentage periodontal pockets ≥4 mm (14.47 vs 4.29, p < 0.05; n = 8). Cognition declined significantly to 12-months (mean ACEIII 71.47 vs 65.40, p < 0.05), but not between 12- and 24-months (67.5 vs 65.38, n = 8). Most reported home-care regimen as easy/OK to follow.

CONCLUSIONS

Mild dementia participants with periodontitis can be recruited, retained in a 24-month study and periodontally treated with personalised professional and at-home care regimens. Cognitive assessments can be performed at the same treatment visit. This demonstrates sustained engagement and supports oral health compliance can be successful in challenging cohorts.

Relationship Between Oral Motor and Cognitive Function in Community-Dwelling Korean Older Adults: A Cross-Sectional, Observational Study

Background: The present study analyzed the relationship between oral motor and cognitive functions in community-dwelling older Korean adults. Methods: Study participants included 113 community-dwelling older adults with a mean age of 73.84 years. Subjects' cognition was assessed using the Korean version of the Montreal Cognitive Assessment, and tongue, cheek, and lip pressures were assessed using the Iowa Oral Performance Instrument. Tongue and masseter thicknesses were measured using an ultrasound device (Sonon, Healcerion, Roseville, CA, USA). The occlusal force was measured using a specialized device (Innobyte, Kube Innovation, Montreal, QC, Canada), and the number of lost teeth was directly verified by a dental hygienist. Results: Results of analysis of cognitive function according to demographic characteristics of older community-dwelling adults revealed a significant difference in cognitive function according to education level and employment status. Cognitive function demonstrated a positive correlation with oral motor function, including pressure on the cheek, lips, and tongue, thickness of the masseter and tongue, occlusal force, number of lost teeth, and age. Hierarchical regression analysis revealed that demographic characteristics and cheek, lip, tongue, and masseter functions did not affect cognition, whereas occlusal force and number of lost teeth significantly affected cognition. In this study, oral motor function, excluding occlusal force and number of lost teeth, did not affect cognition. Conclusions: Future studies, however, are required to analyze the relationship between oral motor function and cognition in older adults with a wider range of such functions.

Healthy ageing and oral health: priority, policy and public health

The global population ageing, and the pace of ageing is accelerating. Although people are living longer, these additional years are not being gained in health, and disability, chronic and long-term conditions increase with age. In response to the challenges of an ageing population, the United Nations and World Health Organisation declared 2021-2030 the Decade of Healthy Ageing, with the purpose of collaborative action to foster longer and healthier lives. This review explores the WHO public health framework for healthy ageing and global trends and policies, using the UK as an example of policy implementation. In response to the urgent need to consider the impact of ageing on oral health and oral healthcare systems, an integrated model for healthy ageing and oral health is proposed.

Orofacial dysfunction after stroke-A multidisciplinary approach

OBJECTIVE

This paper describes the study protocol in an ongoing clinical trial evaluating oral screen training as part of a post-stroke rehabilitation programme. Baseline data were related to four domains: dysphagia, lip function, masticatory performance and patient-related outcome measures (PROM).

BACKGROUND

Stroke is one of the most common causes of disability-adjusted life years, and dysphagia is a common remaining problem after stroke. Rehabilitation using oral screen training has been suggested to improve swallowing, but evidence is still insufficient.

MATERIALS AND METHODS

Patients diagnosed with stroke with persisting objective and/or subjective swallowing dysfunction after primary rehabilitation were assessed for eligibility. In total, 25 patients were included. Objective function was assessed by swallowing capacity test (SCT), lip force and masticatory performance, subjective function by EAT-10 and NOT-S and PROM by LiSat-11 and ESAS.

RESULTS

Baseline data presented a heterogeneous pattern with no significant association between objective and subjective dysfunction. Most of the participants (20/25) showed impaired swallowing capacity in SCT, and 23/24 revealed orofacial dysfunction according to NOT-S. The most common subjective item reported was chewing and swallowing problems (19/24).

CONCLUSION

The heterogenous findings in the included tests and the lack of correlations emphasise the importance of multidisciplinary approaches to identify objective and subjective orofacial post-stroke dysfunction in clinical practice to be able to offer evidence-based individualised care. The included participants were representative of stroke patients with dysphagia, which supports proceeding with the planned intervention.

Association Between Tongue Pressure and Prevalence of Mild Cognitive Impairment in Japan

OBJECTIVE

Although it has been suggested that a decline in oral function is one of the potential risk factors affecting mild cognitive impairment (MCI), evidence is insufficient to draw clear conclusions. This Japanese cross-sectional study examined the association between tongue pressure (TP) and MCI in middle-aged and older adults aged 36-84 years.

METHODS

Study participants were 1019 (368 men and 651 women). TP was evaluated using a TP measurement device. The maximum value of three measurements was used for analysis. MCI was defined as being present if a participant had a Japanese version of the Montreal Cognitive Assessment score of <26. Adjustment was made for age, smoking status, alcohol consumption, leisure-time physical activity, body mass index, hypertension, dyslipidemia, diabetes mellitus, history of depression, number of teeth, employment, education, and household income.

RESULTS

The prevalence of MCI was 45.3%. Among women, compared with the lowest tertile of TP, the second and highest tertiles were significantly associated with a lower prevalence of MCI with a clear dose-response relationship; the adjusted odds ratio (95% confidence intervals) in the second and highest tertiles of TP were 0.54 (0.36-0.83) and 0.55 (0.36-0.84), respectively (p for trend = 0.005). In contrast, no statistically significant association was observed between TP and the prevalence of MCI among men.

CONCLUSIONS

Our findings suggest that higher TP might be inversely associated with the prevalence of MCI in middle-aged and older Japanese women.

Oral Health in Patients Hospitalized Because of Ischemic Stroke

Background/Objectives: Maintenance of good oral health is relevant to overall health and quality of life. Results of many analyses showed that stroke patients had worse oral health than the control population. The aim of this study was a clinical assessment of oral condition in post-stroke patients and a healthy population. Methods: Oral health was assessed in stroke patients on the first day of ischemic stroke, and in a control group of healthy subjects. The number of teeth, the presence of active carious foci, fillings, and prosthetic restorations were evaluated. To assess oral hygiene, the Approximal Plaque Index (API) was used. In periodontal examinations, the presence of dental deposits, the depth of the existing periodontal pockets, tooth mobility, and the Sulcus Bleeding Index (SBI) during probing were assessed. Results: Significantly higher mean values of Decayed Teeth (DT), Missing Teeth (MT), and Decayed, Missing, and Filled Teeth (DMFT) indices were recorded in the study group. The incidence of dental caries, API, and SBI was also significantly higher in the study group. The study and control groups did not differ significantly in the average number of pockets 3 mm deep and deeper and in the frequency of having prosthetic restorations. Conclusions: Oral health and the level of oral hygiene in patients hospitalized because of ischemic stroke, in comparison with that in a healthy population, is not satisfactory. Active interdisciplinary collaboration between various medical specialists in the therapy of patients with general illnesses, including stroke, is strongly recommended.

Hidden dangers: Does multisensory impairments accompanying visual impairment increase dementia risk

BACKGROUND

Growing evidence suggests that sensory impairment, particularly in the form of visual impairment, may contribute to the development of dementia. However, it remains unclear whether experiencing concurrent visual impairment in combination with other types of multisensory impairments may further increase this risk.

METHODS

The study used data from the UK Biobank cohort study, which recruited 500,000 adults. With meticulous screening procedures in place, individuals with visual impairment, hearing impairment, and oral health issues were identified for further follow-up evaluations. A multivariable regression analysis was conducted to investigate the relationship between multisensory impairments concurrent with visual impairment and cognitive function. Cox proportional hazard models were used to estimate hazard ratios and 95% confidence intervals to evaluate the association between multisensory impairments concurrent with visual impairment and dementia risk.

RESULTS

Subjects experiencing multisensory impairments concurrent with visual impairment demonstrated a negative association with cognitive function. Notably, individuals who have both vision and hearing impairments had a significantly higher risk of developing dementia (HR 1.28, 95% CI [1.01-1.63]). Additionally, individuals who experience vision impairment and oral health issues simultaneously were also at higher risk for dementia (HR 1.61, 95% CI [1.32-1.97]). Furthermore, the risk of dementia among individuals with vision impairment, hearing impairment, and oral health issues further escalated to an even higher level (HR 1.63, 95% CI [1.19-2.24]).

CONCLUSIONS

The correlation between the presence of multisensory impairments concurrent with visual impairment and cognitive decline is highly significant. Those with multisensory impairments concurrent with visual impairment are at a significantly increased risk of developing dementia.

Evaluating the Effectiveness of Phellodendron Amurense Ruprecht Extract as a Natural Anti-Caries Material

BACKGROUND

This study aimed to investigate the antibacterial and cytotoxic potential of Phellodendron amurense Ruprecht (PAR) extract against Streptococcus mutans (S. mutans) and explore the possibility of using PAR extract as an anticariogenic agent.

METHODS

Mixed extracts were prepared at 0, 1.25, 2.5, and 5 mg/mL concentrations, and an S. mutans-containing solution of 100 μL was inoculated into the medium. The survival rate of human keratinocyte (HaCaT) cells was assessed to confirm stability. One-way ANOVA was performed to evaluate the antibacterial activity against S. mutans and the proliferation of HaCaT cells.

RESULTS

Higher concentrations of the PAR extract showed more growth inhibition of S. mutans over time, with the complete inactivation of S. mutans at 5 mg/mL. HaCaT cell density was reduced at a PAR extract concentration of 1.25 mg/mL, but IC50 was not observed, confirming that the concentration used did not affect the cytotoxicity and proliferation.

CONCLUSIONS

Results showed that the PAR extract was excellent as a natural substance with anticariogenic effects that inhibited the growth of S. mutans and did not affect the cell viability, thus indicating the potential for clinical application.

Identifying a group of factors predicting cognitive impairment among older adults

BACKGROUND

Cognitive impairment has multiple risk factors spanning several domains, but few studies have evaluated risk factor clusters. We aimed to identify naturally occurring clusters of risk factors of poor cognition among middle-aged and older adults and evaluate associations between measures of cognition and these risk factor clusters.

METHODS

We used data from the National Health and Nutrition Examination Survey (NHANES) III (training dataset, n = 4074) and the NHANES 2011-2014 (validation dataset, n = 2510). Risk factors were selected based on the literature. We used both traditional logistic models and support vector machine methods to construct a composite score of risk factor clusters. We evaluated associations between the risk score and cognitive performance using the logistic model by estimating odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Using the training dataset, we developed a composite risk score that predicted undiagnosed cognitive decline based on ten selected predictive risk factors including age, waist circumference, healthy eating index, race, education, income, physical activity, diabetes, hypercholesterolemia, and annual visit to dentist. The risk score was significantly associated with poor cognitive performance both in the training dataset (OR Tertile 3 verse tertile 1 = 8.15, 95% CI: 5.36-12.4) and validation dataset (OR Tertile 3 verse tertile 1 = 4.31, 95% CI: 2.62-7.08). The area under the receiver operating characteristics curve for the predictive model was 0.74 and 0.77 for crude model and model adjusted for age, sex, and race.

CONCLUSION

The model based on selected risk factors may be used to identify high risk individuals with cognitive impairment.

Cognitive status and dental-related function in older adults seeking community-based dental care: A Pilot Study

OBJECTIVE

This study aims to understand the prevalence of cognitive impairment and dentally-related functional (DRF) loss among older adults seeking community-based dental care.

METHODS AND RESULTS

A total of 149 adults aged 65 or older who visited the University of Iowa College of Dentistry Clinics and who had no prior documented cognitive impairment were recruited in 2017 and 2018. Participants underwent a brief interview, a cognitive assessment, and an assessment of DRF. Bivariate and multivariate analyses were used to assess associations between demographic variables, DRF, and cognitive function. Close to half (40.7%) of the patients presented with some degree of cognitive impairment, and impaired DRF was observed in 13.8%. Compared to those without cognitive impairment, elderly dental patients with cognitive impairment were 15% more likely to present with impaired DRF (odds ratio = 1.15, 95% CI = (1.05, 1.26).

CONCLUSION

Cognitive impairment is likely more prevalent in older adults seeking dental care than is generally understood by providers. Given its impact on DRF, dental providers should be alert to the possible need to evaluate patients' cognitive status and DRF in order to be able to adjust treatment and recommendations accordingly.

Improving oral health of older adults for healthy ageing

The objective of this article is to discuss the importance of oral health in achieving healthy ageing and the role of all stakeholders in improving oral health for older adults. The World Health Organization defined healthy ageing as the process of developing and maintaining the functional ability that enables well-being in older age. It recognized healthy ageing as an important goal and the key to turn population ageing from a challenge to an opportunity. Healthy ageing has positive impacts on individual older adults, their families and societies. It enhances quality of life of older adults, strengthen family bonding of families and reduce resource demand of the societies. Maintaining oral health and function is essential in healthy ageing. Oral health affects systemic health, cognitive health and psychological health. Oral functions such as eating ensure nutritional health in older adults. Most oral diseases are preventable and oral function decline can be recovered by intervention. Unfortunately, oral diseases remain prevalent and oral function decline is being neglected in older adults. Policy makers, national dental associations, academics and healthcare professionals should collaborate to provide a patient-centred, comprehensive and integrated care to older adults. Health policy reforms are needed to reduce the global oral health inequalities in older adults. Population-wide prevention should be accessible, affordable and available to older adults. Universal oral health coverage is crucial for integration of oral health into general health care.

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.

Risk factors of cognitive impairment: Impact of decline in oral function

Cognitive impairment and subsequent dementia are the major causes of disability and need for nursing care among older people in worldwide. The purpose is to review well-known risk factors for cognitive impairment and dementia, focusing on the relationship between decline in oral function and current prevention strategies. Various non-modifiable and modifiable risk factors are related to cognitive impairment. Effects of oral function to cognitive impairment is not yet well recognized in the medical community, although masticatory function, occlusal force, and number of teeth have been reported to be related to cognitive function. Furthermore, occlusal force rather than number of teeth was significantly related to the early stages of cognitive impairment, and that a decline in occlusal force seemed to lead to cognitive impairment directly and indirectly through dietary intake. This relationship was significant only for occlusal force, which may be associated with the early stages of cognitive decline. Nutritional change caused by reduced masticatory function is suggested as a possible explanation. Therefore, rehabilitation or maintenance of oral function should be sought to prevent cognitive impairment.

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.

Views of homecare staff and carers on oral needs and dental care for people living with dementia: A qualitative study

OBJECTIVE

People living with dementia are at risk of mouth and dental problems. Many receive help with this aspect of personal care from family carers or homecare workers. We explored the views of homecare providers and carers on how this aspect of personal care is addressed and implemented.

MATERIALS AND METHODS

In this qualitative study we conducted semi-structured interviews with carers (all family members), homecare workers and managers providing support to people living with dementia in their own homes. Interview questions focused on daily care practices, exploring barriers and facilitators to oral care. Interviews were recorded online or over the telephone, transcribed, and thematically analysed.

RESULTS

Carers (n = 8), homecare workers (n = 9) and homecare managers (n = 15) were recruited from across England in 2021-2022. Across interviews, two main themes were identified: (i) Missed opportunities to address oral care, which is not always seen as a priority despite the importance and potential risk of neglect. (ii) Challenges in delivering oral care, including factors related to the person living with dementia (such as cognitive and physical decline) and factors related to the care infrastructure and policies such as training, perception of roles, allocated time, and consistency of care.

DISCUSSION

More emphasis could be given to the training and skills of homecare providers to identify and prevent dental problems and to assist carers. Several strategies and tools (oral care checklists, greater detail around oral care in care assessments and care plans) could be used to enhance this aspect of personal care for people living with dementia.

Postgraduate dental resident education: A pilot in age-friendly "mentation" training

OBJECTIVE

Postdoctoral dental education in caring for older adults lacks didactic and clinical training in mentation topics, one of the core elements of the Age-Friendly Health Systems (AFHS) framework. Our primary goal was to launch a pilot project in clinical geriatrics focusing on older adults' mentation concerns, with a secondary goal to improve dental residents' confidence and competence in dental care and oral health.

BACKGROUND

Age-friendly care elements are not routinely incorporated into the dental education of residents caring for older adults with cognitive impairment or dementia. Therefore, we implemented a pilot educational project, providing the missing educational opportunity for residents in geriatric training covering cognitive impairment and focusing on Alzheimer's disease and related dementias.

MATERIALS AND METHODS

We designed educational sessions through a needs assessment, focus group discussions, and expert validation. We developed three e-Learning modules covering mentation concerns and dementia screening. We tested the modules in a pilot study of 15 dental postdoctoral residents as an essential part of their clinical practice.

RESULTS

The dementia dental learning module increased the residents' satisfaction with didactic preparedness (4.45 ± $ \pm \ $ 0.97) and knowledge acquisition (4.36 ± $ \pm \ $ 0.84). Residents strongly believed that learning about the AFHS-mentation topic would improve patient care.

CONCLUSION

Our pilot study is a pioneer project in support of a new AFHS-themed dental curriculum for clinical education. Further expansion of the age-friendly principles to include mobility, medications, and what matters to older adults will establish a model framework of redesigned geriatric dental education for academic centers.

Opportunistic health screening for cardiovascular and diabetes risk factors in primary care dental practices: experiences from a service evaluation and a call to action

Introduction Substantial evidence has established associations between oral health and chronic diseases, mediated by common risk factors and inflammatory processes. Dental professionals are aptly positioned to screen for cardiovascular disease and diabetes high-risk indicators. This article presents a service evaluation of two dental practices delivering health screening in dental practice, and a call to action for the wider profession.Methods Following training, two general dental practices implemented a suite of health screens, including blood pressure, blood glucose, cholesterol, body mass index (BMI) and waist-to-height ratio. A service evaluation was undertaken to review and improve service provision.Results Most patients (78.4%) had blood pressure values above normal range. More than half (55.8%) were outside of the healthy range for BMI. Out-of-range results for cholesterol were observed in less than one-fifth (16.7%). High blood glucose values were observed for few patients (3.3%).Conclusion Dental professionals can be successfully trained to deliver health screening interventions. Out-of-range health screening results offer an opportunity to provide targeted health advice for both the oral and general health. Clear protocols and careful interpretation of screening tests are required to minimise patients' confusion. More robust alliances between dental and general medical care are recommended.

Experimental tooth loss affects spatial learning function and blood-brain barrier of mice

OBJECTIVE

This study aims to investigate how experimental tooth loss affected learning, memory function, and brain pathophysiology in mice.

MATERIALS AND METHODS

The mice (C57BL/6 J, 2-month-old, male) were divided into tooth loss and control groups. The behavioral test battery was performed at 6 and 12 months after tooth extraction. The protein levels of the tight junctions in the brains of the mice were analyzed. Hippocampal astrocyte was measured using immunohistochemical staining.

RESULTS

The results of behavioral tests and biochemical analysis performed during the 6 months observation period did not show significant differences between the groups. However, the escape latency in the tooth loss group was significantly longer than that in the control group at the 12 months after tooth extraction. The level of claudin-5 decreased in the tooth loss group. Additionally, hippocampal astrogliosis was found in the tooth loss group.

CONCLUSIONS

Experimental tooth loss reduced the level of claudin-5 and caused astrogliosis in the brains of mice, which was accompanied by deterioration of learning functions. This study may provide a new insight about the association between tooth loss and cognitive dysfunction.

The impact of aromatherapy-based oral care on oral conditions, salivary pH, and halitosis in older adults with dementia: Pilot study

Inadequate oral care and poor oral health in older adults are known to increase the risk of dementia. Dementia patients residing in long-term care facilities are especially vulnerable to oral diseases due to their care-resistant behavior. This study aimed to investigate the effects of a 7-day oral care program based on an aroma solution in 58 dementia patients (29 each in the experimental and control groups) admitted to a long-term care hospital in South Korea. The experimental group received oral care with a solution containing peppermint, tea tree, and lemon essential oils, and the control group with a saline solution. The effectiveness of oral care was assessed by the participants' oral condition, salivary pH, and halitosis. The experimental group showed significant improvements (P<.001) in all three outcomes, indicating that oral care with an aroma solution can improve the oral health of older dementia patients residing in long-term care facilities.

Effects of Alzheimer's disease and related dementias on dental care usage and economic burden in older adults: a cross-sectional study

AIM

Distinct subtypes of Alzheimer's disease (AD) and related dementias (RD) might have different effects on dental care usage and economic burden. To determine the effects of AD and RD on specific types of dental care usage (preventive and treatment visits) and dental care costs from different payers (total and out-of-pocket costs).

METHODS

A cross-sectional study was conducted using the Medicare Current Beneficiary Survey in 2016. This study identified 4268 community dwelling older adults with and without Alzheimer's disease and related dementias (ADRD) from a nationally representative sample of Medicare beneficiaries. Dental care usage and costs are based on self-reported data. Preventive dental events included preventive and diagnosis events. Treatment dental events included restorative, oral surgery and other events.

RESULTS

This study identified 4268 (weighted N=30 423 885) older adults, including 94.48% without ADRD, 1.90% with AD and 3.63% with RD. Compared with older adults without ADRD, those with AD had similar dental care usage, but those with RD were 38% less likely to have treatment visit (OR: 0.62; 95% CI: 0.41 to 0.94) and had a 40% reduced number of total treatment visits (incidence rate ratio: 0.60; 95% CI: 0.37 to 0.98). RD was not associated with dental care costs, but AD was associated with higher total costs (β: 1.08; 95% CI: 0.14 to 2.01) and higher out-of-pocket costs (β: 1.25; 95% CI: 0.17 to 2.32).

CONCLUSIONS

Patients with ADRD were more likely to have adverse dental care outcomes. Specifically, RD was associated with lower treatment dental care usage and AD was associated with higher total and out-of-pocket dental care costs. Effective patient-centred strategies should be used to improve dental care outcomes in patients with distinct subtypes of ADRD.

Relationship between Cognition, Depression, and Oral health status in Older adults: A longitudinal cross-lagged analysis

BACKGROUND

The world's population is aging increasingly, and older adults' physical and mental health needs to be prioritized. Although several studies have explored the relationship between cognition, depression, and oral health in older adults, the exact nature and direction of this relationship are poorly understood. Moreover, most studies to date have been cross-sectional, with fewer longitudinal studies. The current longitudinal study explored the relationship between cognition, depression, and oral health in older adults.

METHODS

We used data from two waves (2018, 2020) of the Korean Longitudinal Study of Aging, which included 4543 older adults aged 60 years and older. General socio-demographic characteristics were analyzed using descriptive analysis, and study variables were described using t-tests. Generalized Estimating Equations (GEE) and cross-lagged models were used to examine the longitudinal associations between cognition, depression, and oral health.

RESULTS

The GEE results suggested that better cognition and less depression over time were associated with better oral health in older adults. Cross-lagged models further validated the effect of depression on oral health over time.

LIMITATIONS

The directionality of the influence of cognition on oral health could not be determined.

CONCLUSIONS

Although there were several limitations, our study provided novel ideas for verifying the effects of cognition and depression on oral health in older adults.

Novel casein antimicrobial peptides for the inhibition of oral pathogenic bacteria

Milk casein is a rich source of antimicrobial peptides (AMPs) and the most common way to produce AMPs is enzymatic hydrolysis in vitro. In this study, active casein antimicrobial peptide (CAMPs) mixtures were generated by optimized proteolytic cleavage of milk casein. These natural-safe CAMPs mixtures exhibited high activity in the inhibition of Streptococcus mutans and Porphyromonas gingivalis. Morphological characterization suggested the pathogenic bacteria presented incomplete or irregular collapsed membrane surface after the treatment with active CAMPs mixtures. The CAMPs inhibition activity was also effective in the attachment and development of microbial biofilm. Potential CAMPs sequences were unambiguously determined by unbiased proteomic analysis and 301 potential CAMPs were obtained. The activity of 4 novel CAMPs was successfully confirmed by using synthetic standards. This study provides a promising milk CAMPs resource for the development of safe agents in oral bacteria inhibition and functional foods.

Poor Oral Health and Risk of Incident Dementia: A Prospective Cohort Study of 425,183 Participants

BACKGROUND

The association between poor oral health and the risk of incident dementia remains unclear.

OBJECTIVE

To investigate the associations of poor oral health with incident dementia, cognitive decline, and brain structure in a large population-based cohort study.

METHODS

A total of 425,183 participants free of dementia at baseline were included from the UK Biobank study. The associations between oral health problems (mouth ulcers, painful gums, bleeding gums, loose teeth, toothaches, and dentures) and incident dementia were examined using Cox proportional hazards models. Mixed linear models were used to investigate whether oral health problems were associated with prospective cognitive decline. We examined the associations between oral health problems and regional cortical surface area using linear regression models. We further explored the potential mediating effects underlying the relationships between oral health problems and dementia.

RESULTS

Painful gums (HR = 1.47, 95% CI [1.317-1.647], p <  0.001), toothaches (HR = 1.38, 95% CI [1.244-1.538], p <  0.001), and dentures (HR = 1.28, 95% CI [1.223-1.349], p <  0.001) were associated with increased risk of incident dementia. Dentures were associated with a faster decline in cognitive functions, including longer reaction time, worse numeric memory, and worse prospective memory. Participants with dentures had smaller surface areas of the inferior temporal cortex, inferior parietal cortex, and middle temporal cortex. Brain structural changes, smoking, alcohol drinking, and diabetes may mediate the associations between oral health problems and incident dementia.

CONCLUSION

Poor oral health is associated with a higher risk of incident dementia. Dentures may predict accelerated cognitive decline and are associated with regional cortical surface area changes. Improvement of oral health care could be beneficial for the prevention of dementia.

Oral health literacy and its associated factors among nurses: A cross-sectional study

AIMS AND OBJECTIVES

To investigate the oral health literacy (OHL) of nurses and explore the factors affecting their OHL.

BACKGROUND

OHL is important for improving the oral health outcomes. Nurses' OHL may affect the oral health of themselves, families, and patients. Few studies have examined the OHL and its related factors among nurses.

DESIGN

A cross-sectional design following the STROBE guideline.

METHODS

A total of 449 nurses were recruited from tertiary hospitals in the minority areas of southwest China. The participants completed an online questionnaire, which contained questions related to the OHL, sociodemographic factors, general health, oral health and related behaviours, oral health knowledge, attitudes, and oral health-related quality of life. OHL was measured using the validated Chinese version of the short-form Health Literacy of Dentistry (HeLD-14) scale. Descriptive statistics, the Mann-Whitney U test, Spearman's correlation, and multiple linear regression analysis were used to analyse the data.

RESULTS

The median HeLD-14 score (p25-p75) was 50.0 (44.0-54.0). The regression model for OHL was found to be significant. The factors that influenced OHL included oral health knowledge, oral health attitudes, self-reported oral health, annual household income, and dental flossing; these factors accounted for 13.9% of the variance in OHL.

CONCLUSIONS

The nurse' OHL has room for improvement. Nurses' OHL could be improved by enriching their oral health knowledge, promoting their positive oral health attitudes, increasing their household income, and helping them build correct oral health behaviours.

RELEVANCE TO CLINICAL PRACTICE

The findings of the study could be used to make a case for changing nursing curricula. Oral health knowledge curriculum or programmes targeted towards nurses should be developed to improve their OHL.

PATIENT OR PUBLIC CONTRIBUTION

No Patient or Public Contribution.

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.

Antibodies against Periodontal Microorganisms and Cognition in Older Adults

INTRODUCTION

Markers of poor oral health are associated with impaired cognition and higher risk of Alzheimer disease (AD) and thus may help predict AD.

OBJECTIVES

The aim of this study was to evaluate the cross-sectional association between empirically derived groups of 19 IgG antibodies against periodontal microorganisms and cognition in middle-aged and older adults.

METHODS

The study population consisted of participants of the third National Health and Nutrition Examination Survey (NHANES III) (1988 to 1994), who were 60 y and older, among whom cognition and IgG antibodies against 19 periodontal microorganisms were measured (N = 5,162).

RESULTS

In multivariable quantile regression analyses, the Orange-Red (Prevotella melaninogenica, Prevotella intermedia, Prevotella nigrescens, Porphyromonas gingivalis) and Yellow-Orange (Staphylococcus intermedius, Streptococcus oralis, Streptococcus mutans, Fusobacterium nucleatum, Peptostreptococcus micros, Capnocytophaga ochracea) cluster scores were negatively associated with cognition. A 1-unit higher cluster score for the Orange-Red cluster was associated on average with a lower cognitive score (β for 30th quantile = -0.2640; 95% confidence interval [CI], -0.3431 to -0.1848). Similarly, a 1-unit higher score for the Yellow-Orange cluster was associated with a lower cognitive score (β for 30th quantile = -0.2445; 95% CI, -0.3517 to -0.1372).

CONCLUSION

Groups of IgG antibodies against periodontal microorganisms were associated with lower cognition among free living adults 60 years and older, who were previously undiagnosed with cognitive impairment. Though poor oral health precedes the development of dementia and AD, oral health information is currently not used, to our knowledge, to predict dementia or AD risk. Combining our findings with current algorithms may improve risk prediction for dementia and AD.

KNOWLEDGE TRANSLATION STATEMENT

IgG antibodies against periodontal microorganisms were associated with lower cognition among adults 60 years and older previously undiagnosed with cognitive impairment. Periodontal disease may predict cognition among older adults.

Poor Oral Health as a Risk Factor for Dementia in a Swedish Population: A Cohort Study with 40 Years of Follow-Up

BACKGROUND

Whether poor oral health is associated with dementia risk remains unclear.

OBJECTIVE

We conducted a cohort study of 14,439 participants who were followed up for up to 40 years in Uppsala County, central Sweden, aiming to explore the association between poor oral health, namely the number of tooth loss, dental plaque status, and oral mucosal lesions, and the risk of dementia.

METHODS

We used Cox proportional hazards regression model to derive cause-specific hazard ratios (HR) and corresponding 95% confidence intervals (CI), while adjusting for baseline potential confounders as well as a time-varying covariate, Charlson's Comorbidity Index score.

RESULTS

Dementia risk was substantially higher among those with a higher number of tooth loss; compared to the group with tooth loss 0-10, the HRs were 1.21 (95% CI: 1.02, 1.42), 1.17 (95% CI: 0.97, 1.40), and 1.30 (95% CI: 1.09, 1.54) respectively for groups with increasing number of tooth loss. There was some evidence of dose-risk association in this study, with a HR of 1.10 (1.04, 1.18) comparing adjacent groups (ptrend = 0.001). In a stratified analysis by attained age, tooth loss was more pronouncedly associated with the risk of dementia onset before age 80 (those with 21-32 versus 0-10 lost teeth, HR = 1.82, (95% CI: 1.32, 2.51); HR = 1.22 (95% CI: 1.10, 1.35) comparing adjacent groups, ptrend < 0.001).

CONCLUSION

In summary, there are some indications that poor oral health, as indicated by more tooth loss, is positively associated with an increased risk of dementia, especially for dementia onset before age 80.

Association between adverse oral conditions and cognitive impairment: A literature review

Oral environment deterioration results from a lack of self-cleaning ability in patients with cognitive dysfunction but is also a risk factor for cognitive dysfunction. Adverse oral conditions can be alleviated and improved through a self-management and medical examination. In this review, the epidemiological evidence of previous studies is integrated to highlight the relationship between periodontitis, tooth loss, oral flora, oral dysfunction and cognitive dysfunction, emphasizing the importance of oral health for cognition. The results show that poor oral condition is associated with cognitive impairment. Although many previous studies have been conducted, there is a lack of higher-level research evidence, different judgment criteria, and conflicting research results. There is a bidirectional relationship between oral health and cognitive dysfunction. A comprehensive analysis of the relationship between oral health and cognitive dysfunction that explores the relationship and takes measures to prevent cognitive dysfunction and control the progression of such diseases is warranted in the future.

Is Periodontitis Associated with Age-Related Cognitive Impairment? The Systematic Review, Confounders Assessment and Meta-Analysis of Clinical Studies

It has been suggested that molecular pathological mechanisms responsible for periodontitis can be linked with biochemical alterations in neurodegenerative disorders. Hypothetically, chronic systemic inflammation as a response to periodontitis plays a role in the etiology of cognitive impairment. This study aimed to determine whether periodontitis (PDS) is a risk factor for age-related cognitive impairment (ACI) based on evidence of clinical studies. A comprehensive, structured systematic review of existing data adhering to the Preferred Reporting Items for Systematic Review and Meta Analyses (PRISMA) guidelines was carried out. Five electronic databases, PubMed, Embase, Scopus, Web of Science, and Cochrane, were searched for key terms published in peer-reviewed journals until January 2021. The Newcastle-Ottawa scale was used to assess the quality of studies and risk of bias. The primary and residual confounders were explored and evaluated. A meta-analysis synthesizing quantitative data was carried out using a random-effects model. Seventeen clinical studies were identified, including 14 cohort, one cross-sectional, and two case-control studies. Study samples ranged from 85 to 262,349 subjects, with follow-up between 2 and 32 years, and age above 45 years, except for two studies. The findings of studies suggesting the PDS-ACI relationship revealed substantial differences in design and methods. A noticeable variation related to the treatment of confounders was observed. Quality assessment unveiled a moderate quality of evidence and risk of bias. The subgroups meta-analysis and pooled sensitivity analysis of results from seven eligible studies demonstrated overall that the presence of PDS is associated with an increased risk of incidence of cognitive impairment (OR = 1.36, 95% CI 1.03-1.79), particularly dementia (OR = 1.39, 95% CI 1.02-1.88) and Alzheimer's disease (OR = 1.03 95% CI 0.98-1.07)). However, a considerable heterogeneity of synthesized data (I2 = 96%) and potential publication bias might affect obtained results. While there is a moderate statistical association between periodontitis and dementia, as well as Alzheimer's disease, the risk of bias in the evidence prevents conclusions being drawn about the role of periodontitis as a risk factor for age-related cognitive impairment.

Understanding dental caries as a non-communicable and behavioral disease: Management implications

New paradigms in caries conceptualization have emerged during the last decades, leading to intense debate and discussion on how to approach the disease, both from a preventive and a therapeutic perspective. Among many new ideas, research discoveries and technologies, one major concept can be highlighted that created a deep frontier between the old and the new paradigm in caries conceptualization; the non-communicable nature of the disease, firmly associated with behaviors and lifestyles. This article synthetizes the conceptual construction of dental caries as a non-communicable disease (NCD) based on the current evidence and discusses the appropriate management of the disease in this context. Dental caries has shifted from being considered transmissible and infectious to an ecological and non-communicable disease. Environmental factors such as frequent sugars intake, disrupt the symbiosis of the dental biofilm leading to a dysbiosis, which favors caries lesion initiation and progression. As an NCD, dental caries shares characteristics with other NCDs such as cardiovascular and chronic respiratory diseases, cancer and diabetes, including long duration and slow progression, not being transmissible from person-to-person, being strongly related to modifiable behavioral risk factors, and affecting preferentially disadvantaged populations with a strong inequality gradient. Given the high prevalence of dental caries, and its consequences on people's health and quality of life, a recognizable conceptual view of caries as a NCD is required to target an effective management. Current understanding of dental caries supports prevention through acting on the modifiable risk factors (behaviors) and involves management based on an interdisciplinary approach. Communicating these modern concepts among researchers, clinicians and policymakers is needed to decrease the global high burden of the disease.

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.

Interplay of gut microbiota and oxidative stress: Perspective on neurodegeneration and neuroprotection

Background

Recent research on the implications of gut microbiota on brain functions has helped to gather important information on the relationship between them. Pathogenesis of neurological disorders is found to be associated with dysregulation of gut-brain axis. Some gut bacteria metabolites are found to be directly associated with the increase in reactive oxygen species levels, one of the most important risk factors of neurodegeneration. Besides their morbid association, gut bacteria metabolites are also found to play a significant role in reducing the onset of these life-threatening brain disorders.

Aim of Review

Studies done in the recent past raises two most important link between gut microbiota and the brain: "gut microbiota-oxidative stress-neurodegeneration" and gut microbiota-antioxidant-neuroprotection. This review aims to gives a deep insight to our readers, of the collective studies done, focusing on the gut microbiota mediated oxidative stress involved in neurodegeneration along with a focus on those studies showing the involvement of gut microbiota and their metabolites in neuroprotection.

Key Scientific Concepts of Review

This review is focused on three main key concepts. Firstly, the mounting evidences from clinical and preclinical arenas shows the influence of gut microbiota mediated oxidative stress resulting in dysfunctional neurological processes. Therefore, we describe the potential role of gut microbiota influencing the vulnerability of brain to oxidative stress, and a budding causative in Alzheimer's and Parkinson's disease. Secondly, contributing roles of gut microbiota has been observed in attenuating oxidative stress and inflammation via its own metabolites or by producing secondary metabolites and, also modulation in gut microbiota population with antioxidative and anti-inflammatory probiotics have shown promising neuro resilience. Thirdly, high throughput in silico tools and databases also gives a correlation of gut microbiome, their metabolites and brain health, thus providing fascinating perspective and promising new avenues for therapeutic options.

The prospective association between periodontal disease and brain imaging outcomes: The Atherosclerosis Risk in Communities study

AIM

We investigate if periodontal disease is prospectively associated with cerebrovascular and neurodegenerative markers of dementia and Alzheimer's pathology.

MATERIALS AND METHODS

N = 1306 participants (Visit 5 mean age = 76.5 [standard deviation = 5.4] years) in the Atherosclerosis Risk in Communities study with completed dental exams at Visit 4 underwent brain magnetic resonance imaging scans at Visit 5 while N = 248 underwent positron emission tomography scans. Participants were classified as edentulous or, among the dentate, by the modified Periodontal Profile Class. Brain volumes were regressed on periodontal status in linear regressions. Cerebrovascular measures and β-amyloid positivity were regressed on periodontal status in logistic regressions.

RESULTS

Periodontal disease was not associated with brain volumes, microhaemorrhages, or elevated β-amyloid. Compared with periodontally healthy individuals, odds ratios [95% confidence interval] for all-type infarcts were 0.37 [0.20, 0.65] for severe tooth loss and 0.56 [0.31, 0.99] for edentulous participants.

CONCLUSIONS

Within the limitations of this study, periodontal disease was not associated with altered brain volumes, microhaemorrhages, or β-amyloid positivity. Tooth loss was associated with lower odds of cerebral infarcts.

Low ambient temperature as a novel risk factor of oral diseases: A time-series study

BACKGROUND

The seasonal variation of oral diseases has been observed in life, but the influences of oral diseases associated with non-optimal ambient temperature were unknown.

OBJECTIVE

To examine whether non-optimum ambient temperature is associated with increased risks of oral diseases.

METHODS

We conducted a time series study based on outpatient data from the Shanghai Health Information Center, containing all public hospitals in Shanghai from 2016 to 2019. Generalized additive models with distributed lagged nonlinear models were applied to fit the data.

RESULT

A total of 3,882,636 outpatient cases of oral diseases were collected. Low temperature (<7 °C) posed increased risks for oral diseases. Daily temperature above 7 °C had no effect on oral diseases. The excess risks were present on the lag 1 day and lasted till lag 7 day. Relative to referent temperatures, the cumulative risks of total oral diseases, pulpitis, periodontitis, gum pain, stomatitis, and glossitis at extreme low temperature (-3 °C, 1st percentile) over lag 0-7 day were 1.92 (95% confidence interval, CI: 1.40, 2.63), 2.40 (95% CI: 1.78, 3.25), 1.62 (95% CI: 1.15, 2.29), 1.75 (95% CI: 1.08, 2.83), 1.81 (95% CI: 1.30, 2.53), and 2.22 (95% CI: 1.23, 3.99). These associations were larger in patients who were above age 60.

CONCLUSION

This study provided novel epidemiological evidence that low ambient temperature may increase the risks of oral diseases. The temperature thresholds for eight oral diseases range from 3 to 7 °C. The excess risks could last for 7 days and were larger in older patients.

The mouth and oral health in the field of dementia

An ageing population, an estimated 47 million people currently living with dementia, and predictions of a threefold increase in people living with a diagnosis by 2050 have led the WHO to declare dementia a public health priority. Emerging research also suggests that dementia is linked to poor oral health and that oral health declines alongside cognitive decline. Drawing on Bourdieu's concepts of field and capital, this paper presents an analysis of interview data from participants with dementia, carers and carer/diagnosed dyads participating in a qualitative study of the mouth and oral health. We argue that Bourdieu's conceptual toolkit provides a way of contextualising experiences of oral health within dementia and un-picking the multi-layered impact of structure, institutions, biology, resource mobilisation and self in the context of a progressive disease which ultimately challenges knowledge of the self and the ability to interact with the world around us.

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.

Everyday experiences of people living with dementia and their carers relating to oral health and dental care

Little is known about how community-dwelling people with dementia, as well as their carers, look after their oral health and use dental care. This exploratory study aimed to explore the beliefs, experiences and practices about oral health of people living with dementia and their carers. We used an ethnographic qualitative approach conducting face-to-face interviews at home with people living with dementia and/or carers. Interview data and field notes were analysed thematically using framework methods. We approached volunteers registered with the online UK. Join Dementia Research network from whom a total of 17 participants were recruited in 2018. Five interviews were conducted with carers alone, two with a person living with dementia alone, and five with a carer and person with dementia jointly. Three main themes emerged: oral health is not prioritised; access to dental care is shaped by increasing disability; and the importance of continuity of care. While people living with dementia and their carers may view oral health important once prompted, many reported difficulties in undertaking or assisting with daily self-care and accessing dental services, particularly as dementia progresses. We draw out implications for the organisation and delivery of public and private dental services.

[Design, screening and antibacterial activity evaluation of the novel antibacterial peptide KR-1]

OBJECTIVE

To design novel antimicrobial peptides with high activity and low toxicity and evaluate their effect against Streptococcus mutans and other oral bacteria for prevention and treatment of dental caries.

OBJECTIVE

We synthesized two antimicrobial peptides (KR-1 and KR-2) using Dhvar4 (a histatins5 mimic) as the template. The antimicrobial peptides with high activity and low toxicity were screened using minimal inhibitory concentration (MIC) test, hemolysis test, and CCK-8 assay. Streptococcus mutans biofilms cultured in 96-well plates were divided into experimental group (KR-1) and positive control group (CHX) and treated with concentration gradients (0.6×, 0.8×, 1× and 2× MICs) of KR-1 and CHX, respectively. Crystal violet staining was used for quantitative analysis of the changes of the biofilms after the treatments. The structural changes of the biofilms were observed with laser confocal microscopy after KR-1 treatment at 10 × MIC. The antimicrobial activity of KR-1 against oral Streptococcus was analyzed based on the time required for sterilization after KR-1 treatment.

OBJECTIVE

The MIC of KR-1 and KR-2 for S. mutans was 3.2 μmol/L and 12.8 μmol/L, respectively. Under the effective concentration, KR-1 and KR-2 resulted in hemolysis rates of 0.35% and 48.8% in rabbit red blood cells and lowered the survival rates of gingival fibroblasts to 88.7% and 21.94%, respectively. KR-1 treatment significantly reduced biofilm formation with a minimum biofilm inhibition concentration (MBIC₅₀) lower than 1.92 μmol/L, and showed an even stronger antimicrobial than CHX at the concentration of 2.56 μmol/L (P=0.001). Confocal laser scanning microscopy revealed that the biofilm structure became loosened after KR-1 treatment, which was capable of killing about 90% of the bacteria within 5 min.

OBJECTIVE

The antimicrobial peptide KR-1 has a stronger antibacterial activity and a low toxicity with a good inhibitory effect against S. mutans biofilm.

Maintaining and improving mouth care for care home residents: A participatory research project

BACKGROUND

Many people residing in nursing or residential care homes (also called long-term care facilities) live with physical or cognitive difficulties. Staff working in these environments often help residents (particularly those with more advanced dementia) with their personal care needs, including maintaining mouth care and health. Poor oral health is associated with many difficulties, including increased risk of respiratory problems, pain and discomfort. Yet, concerns have been raised that staff may not have the knowledge and skills to effectively support residents with oral care and health. There is therefore an important gap between what is known about the importance of maintaining oral health (scientific evidence) and daily practice in long-term care environments.

OBJECTIVES

To work with care home staff: (1) to create a learning culture to address how to promote mouth care for residents, particularly when a resident resists support with this aspect of care; and (2) to effect mouth care practice changes (if required) using participatory and inclusive research cycles.

METHODS AND RESULTS

We conducted a participatory research project to address this important area of care. Four participatory research 'cycles' were conducted. Cycle one explored existing literature to develop accessible guidance on strategies that staff could use to support residents to maintain and improve oral care, particularly when a resident may resist such care. Cycle two built on this review to determine knowledge levels within the care team. This highlighted deficiencies in staff knowledge, skills and competence for providing mouth care and their need for training to address this. Cycle three identified evidence-based strategies to develop staff understanding and knowledge. Cycle four brought together experts from nursing, dentistry, behaviour change, systematic reviews and care homes research to develop a grant application to progress this work further.

CONCLUSION

This paper provides an example of the processes undertaken in a participatory research project, bringing together science and practice to improve an essential area of care.

IMPLICATIONS FOR PRACTICE

Using participatory research approaches in this setting can allow the effective translation of uncertainties in care and practice into questions that can be addressed by research, leading to meaningful outcomes for those living and working in care homes.

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.