Association Between Tooth Loss, Receipt of Dental Care, and Functional Disability in an Elderly Japanese Population: The Tsurugaya Project

Number of teeth and functional disability in community-dwelling older adults

INTRODUCTION

This study determined whether tooth loss was associated with the development of functional disability and estimated the population attributable fraction (PAF) of functional disability due to tooth loss, along with risk factors for functional disability such as physical function and cognitive impairment.

METHODS

The participants were 838 community-dwelling older adults aged ≥70 years living in the Tsurugaya district in Japan in 2003. The exposure variable was the number of remaining teeth (counted by trained dentists). Other variables were age, sex, depressive symptoms, cognitive impairment, educational attainment, physical function and social support. The Cox proportional hazards model was applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of the incidence of functional disability for each risk factor, such as tooth loss. The functional disability PAF due to tooth loss was estimated, and risk factors for functional disability were identified.

RESULTS

In total, 619 (73.9%) participants developed functional disability during follow-up. A multivariable model showed that those with <20 teeth (HR, 1.28; 95% CI, 1.08-1.53) were more likely to develop functional disability than those with 20 teeth or more. PAF estimation for functional disability was shown to have decreasing values in the following order: age, female sex, tooth loss and reduced physical function.

CONCLUSIONS

Tooth loss was associated with the development of functional disability in community-dwelling older Japanese adults. While retaining teeth may be a potential strategy for avoiding functional disability, clinical studies on the effect of dental treatment on preventing functional disability are warranted.

Association between oral health and nutritional status among older patients requiring long-term care who received home-visit dental care

PURPOSE

This study examined the association between oral health and nutritional status among older patients receiving home-visit dental care.

METHODS

This study enrolled 110 older patients (age ≥65 years) requiring long-term care who received home-visit dental care. The oral health indicators evaluated included number of teeth, occlusal support, number of functional teeth, tongue pressure, tongue coating index (TCI), and rinsing ability. Nutritional indicators included skeletal muscle mass index (SMI) and the mini-nutritional assessment short-form (MNA-SF). A multivariate modified Poisson regression analysis (adjusted for age, sex, medical history, care level, and housing type) was used to calculate prevalence ratios and 95% confidence intervals (CIs).

RESULTS

The prevalence ratio for low SMI was not significantly higher for patients with ≥20 teeth than for those with 1-19 or no teeth. Number of teeth was not significantly associated with MNA-SF score. A high TCI score (2.15, 95% CI: 1.07-4.32) and poor rinsing ability (2.32, 95% CI: 1.25-4.30) were significantly associated with low SMI. High TCI scores were associated with low scores in MNA-SF categories (1.25, 95% CI: 1.01-1.55).

CONCLUSION

TCI and rinsing ability, rather than number of teeth, were associated with nutritional status in older patients requiring long-term care.

Association between oral health and locomotive syndrome: a cross-sectional study in Japanese adults

BACKGROUND

Many studies have examined the association between oral health, care needs, and physical function, but few have focused on the association between oral health and locomotive syndrome (LS). We examined the association between LS and oral-health status, such as the number of teeth and chewing function, in an adult population.

METHODS

The study included 2888 participants who underwent examinations of motor function and oral health. Individuals with LS stage 1 or higher were classified as having LS, while others were classified as not having it. Logistic regression analysis was performed using the presence or absence of LS as the dependent variable and age, sex, smoking status, drinking habit, exercise habit, walking speed, history of stroke, bone density, body mass index, metabolic syndrome, chewing function, and the number of teeth as independent variables to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for each independent variable.

RESULTS

When the number of teeth and chewing function were included separately in multivariate analyses, the OR for LS was significantly higher for participants with 0-19 teeth than for those with 28 teeth, and for participants with poor chewing function than for those with good function (adjusted ORs, 1.47 [95% CI, 1.01-2.15] and 1.73 [95% CI, 1.37-2.18], respectively). In analyses that included tooth number and chewing function as a combined independent variable, relative to individuals with 28 teeth and good masticatory function, the adjusted ORs were 2.67 (95% CI, 1.57-4.52) for those with 28 teeth and poor chewing function, 1.63 (95% CI, 1.20-2.22) for those with 20-27 teeth and poor chewing function, and 1.83 (95% CI, 1.06-3.18) for those with 0-19 teeth and poor chewing function.

CONCLUSION

Having fewer teeth and poor chewing function may be associated with LS. The maintenance of masticatory function may be important to prevent LS in adulthood.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

Cooperation between physicians and dentists for osteonecrosis of the jaw: a 2022 Japanese survey

INTRODUCTION

A 2015 survey of the Japan Osteoporosis Society (JOS) on medication-related osteonecrosis of the jaw (MRONJ) revealed that cooperation between physicians and dentists was poor. Discontinuation of antiresorptive agents before tooth extraction was found to increase adverse events without preventing MRONJ. We compared this 2015 survey with a new survey conducted in 2022 to investigate cooperation between physicians and dentists for MRONJ.

MATERIALS AND METHODS

A web-based structured questionnaire including 13 key queries was sent to 3813 physicians who were members of JOS, and 1227 (32.2%) responses were received.

RESULTS

Of the 1227 respondents, 909 (74.1%) had complied with a discontinuation request from a dentist before tooth extraction, although 25.4% of medications were not related to the incidence of MRONJ. Of these, 177 respondents reported 252 adverse events including 10 (1.3%) cases of MRONJ. The prevalence of fractures increased from 4.8% in 2015 to 8.2% in 2022. The rates of respondents who requested oral health care by a dentist before antiresorptive agent therapy and reported cooperation between physicians and dentists were 72.7% and 42.4% in 2022 compared with 32.9% and 24.8% in 2015, respectively. The rates of cooperation among the 47 prefectures in Japan were significantly different, ranging from 10.0 to 83.3% (p = 0.02).

CONCLUSION

This study confirmed increased cooperation between physicians and dentists for MRONJ in Japan. However, a more equal distribution of cooperation across Japan is necessary to optimally manage MRONJ. Discontinuation of antiresorptive agents is no longer necessary because fractures during discontinuation continue to increase in Japan.

Association between tooth loss and frailty among Chinese older adults: the mediating role of dietary diversity

BACKGROUND

This study aimed to examine the association between tooth loss and frailty among Chinese older adults and the mediating role of dietary diversity in this association.

METHODS

Data from five waves of the Chinese Longitudinal Healthy Longevity Survey conducted between 2005 and 2018 were used. Path analyses were employed to assess both concurrent and cross-lagged relationships between tooth loss and frailty index while accounting for intrapersonal correlation. Furthermore, the mediation effect of dietary diversity was also examined.

RESULTS

In concurrent models, severe tooth loss was associated with frailty after adjusting for demographic characteristics (odds ratio [OR] = 1.82, p < 0.001). The OR of frailty for severe tooth loss was only slightly decreased to 1.74 (p < 0.001) when dietary diversity was added to the model and to 1.64 (p < 0.001) when socioeconomic status, family support, and healthy lifestyles were further adjusted. In the cross-lag or longitudinal models, the ORs were mildly or moderately reduced to 1.29, 1.27, and 1.23, respectively, yet remained statistically significant (p < 0.001 or p < 0.01). The mediation analyses showed that dietary diversity had some small yet significant effects on the relationship between tooth loss and frailty in both concurrent and longitudinal settings.

CONCLUSIONS

This study improves current knowledge regarding the impact of tooth loss on frailty among Chinese older adults. Future intervention strategies designed to improve healthy diets may have preventive effects against the risk of frailty among Chinese older adults with severe tooth loss.

Accelerometer-measured sedentary behavior and risk of functional disability in older Japanese adults: a 9-year prospective cohort study

BACKGROUND

The associations of sedentary time and patterns with functional disability among older adults remain unclear, and few studies have accounted for the co-dependency of sedentary behavior and physical activities when modeling sedentary behavior with risk of functional disability. We aimed to examine the associations between sedentary time and patterns and risk of incident functional disability, and assess whether replacing sedentary time with light physical activity (LPA) or moderate-to-vigorous intensity physical activity (MVPA) is associated with reduced risk of functional disability in community-dwelling older adults.

METHODS

A total of 1,687 Japanese adults aged ≥ 65 years without functional disability at baseline were prospectively followed-up for 9 years (2011-2020). Functional disability was ascertained using the national database of Japan's Long-term Care Insurance System. Sedentary time and patterns, LPA, and MVPA were measured using a tri-axial accelerometer secured to participants' waists.

RESULTS

During follow-up, 466 participants developed functional disability. Compared with the lowest quartile of total sedentary time, the multivariable-adjusted hazard ratios (95% confidence intervals) of functional disability for the second, third, and top quartiles were 1.21 (0.91‒1.62), 1.45 (1.10‒1.92), and 1.40 (1.05‒1.88) (p for trend = 0.01). After further adjusting for MVPA, total sedentary time was no longer significantly associated with the risk of functional disability (p for trend = 0.41). Replacing 10 min/day of sedentary time with the same amount of MVPA (but not LPA) was significantly associated with a 12% reduced risk of functional disability (hazard ratio [95% confidence interval]: 0.88 [0.84‒0.92]). No significant association was observed between sedentary bout length and functional disability.

CONCLUSION

Higher levels of total sedentary time were associated with an increased risk of incident functional disability. However, this association was not independent of MVPA. Replacing sedentary time with MVPA, but not LPA, was associated with reduced risk of functional disability in older adults.

An Overview of Systemic Health Factors Related to Rapid Oral Health Deterioration among Older People

The oral health of older individuals can be negatively impacted by various systemic health factors, leading to rapid oral health deterioration. This paper aims to present an overview of the published evidence on systemic health factors that contribute to rapid oral health deterioration in older individuals, and to explore the implications of these factors for both general healthcare and oral healthcare provision. Older people are at risk of experiencing adverse reactions to medications due to multimorbidity, polypharmacy, and changes in pharmacokinetics and pharmacodynamics. Hyposalivation, a significant side effect of some medications, can be induced by both the type and number of medications used. Frailty, disability, sarcopenia, care dependency, and limited access to professional oral healthcare can also compromise the oral health of older people. To prevent rapid oral health deterioration, a comprehensive approach is required that involves effective communication between oral healthcare providers, other healthcare providers, and informal caregivers. Oral healthcare providers have a responsibility to advocate for the importance of maintaining adequate oral health and to raise awareness of the serious consequences of weakened oral health. By doing so, we can prevent weakened oral health from becoming a geriatric syndrome.

Oral frailty indicators to target major adverse health-related outcomes in older age: a systematic review

A well-preserved oral function is key to accomplishing essential daily tasks. However, in geriatric medicine and gerodontology, as age-related physiological decline disrupts several biological systems pathways, achieving this objective may pose a challenge. We aimed to make a systematic review of the existing literature on the relationships between poor oral health indicators contributing to the oral frailty phenotype, defined as an age-related gradual loss of oral function together with a decline in cognitive and physical functions, and a cluster of major adverse health-related outcomes in older age, including mortality, physical frailty, functional disability, quality of life, hospitalization, and falls. Six different electronic databases were consulted by two independent researchers, who found 68 eligible studies published from database inception to September 10, 2022. The risk of bias was evaluated using the National Institutes of Health Quality Assessment Toolkits for Observational Cohort and Cross-Sectional Studies. The study is registered on PROSPERO (CRD42021241075). Eleven different indicators of oral health were found to be related to adverse outcomes, which we grouped into four different categories: oral health status deterioration; decline in oral motor skills; chewing, swallowing, and saliva disorders; and oral pain. Oral health status deterioration, mostly number of teeth, was most frequently associated with all six adverse health-related outcomes, followed by chewing, swallowing, and saliva disorders associated with mortality, physical frailty, functional disability, hospitalization, and falls, then decline in oral motor skills associated with mortality, physical frailty, functional disability, hospitalization, and quality of life, and finally oral pain was associated only with physical frailty. The present findings could help to assess the contribution of each oral health indicator to the development of major adverse health-related outcomes in older age. These have important implications for prevention, given the potential reversibility of all these factors.

Focus on Liability of Residences for Elderly and Sick People: A Case Series and Medico-Legal Issues

Residences for elderly and sick people, self-sufficient or dependent, are varied. To date, the liability profiles of these structures are not clearly delineated, and increasingly often, their operating and organization criteria are entrusted to subnational, regional, or local regulations. Among the various deficits, there is the keeping of a complete and detailed documentation/diary of the patient, the lack of which can generate medico-legal problems. In this paper, we present three cases of guests in residences for a dependent person brought to the attention of the Institute of Forensic Medicine of the University Hospital of Palermo due to criminal proceedings, where the lack of existing documentation in the structure and, in some cases, the behavior of the professionals working there, led the evaluator to deduce the organization's culpability.

Association of self-rated chewing function and oral health status with metabolic syndrome

PURPOSE

The study aimed to examine the association of self-rated chewing function, the number of teeth and periodontal status with metabolic syndrome.

METHODS

The participants were 11,119 adults aged 40-74 years who underwent specific health checkups, including an oral health examination, in 2018 in Japan. This study used the standard questions of the specific health checkups to obtain information on self-rated chewing function. A multinomial logistic regression analysis was performed with metabolic syndrome status as the dependent variable, and age, sex, lifestyle questions, self-rated chewing function, number of teeth, and periodontal status as the independent variables.

RESULTS

Number of teeth and periodontal status were significantly associated with metabolic syndrome after adjusting for confounding variables. Self-rated chewing function was significantly associated with metabolic syndrome in the crude analysis, but not after adjustment for confounding variables. Both number of teeth and periodontal status were significantly associated with self-rated chewing function.

CONCLUSION

There was no significant direct association between self-rated chewing function and metabolic syndrome. Self-rated chewing function may be an indicator of poor oral condition that links to metabolic syndrome.

Tooth Loss Trajectories and Their Association with Functional Disability among Older Chinese Adults: Results from the Chinese Longitudinal Healthy Longevity Survey

BACKGROUND

Tooth loss becomes more prevalent with age and increases risk of functional disability. However, the strength of tooth loss varies between individuals rather than a uniform loss with age. We aimed to evaluate tooth loss trajectories and their association with functional disability among older Chinese adults.

METHODS

We included 16,209 participants aged ≥65 years from five waves of the Chinese Longitudinal Healthy Longevity Survey 2002-2014. The number of teeth, Activities of Daily Living (ADL), and Instrumental ADL (IADL) were assessed at baseline and subsequently every three years. ADL disability and IADL disability were defined as needing any help in any item of the Katz scale and a modified Lawton's scale, respectively. A group-based trajectory model was used to determine tooth loss trajectories based on the self-reported number of teeth and generalized estimating equation models were used to explore associations of tooth loss trajectories with ADL disability and IADL disability.

RESULTS

This study identified four tooth loss trajectories, including Progressively Mild Loss (14.4%), Progressively Severe Loss (21.5%), Persistently Severe Loss (45.1%), and Edentulism (19.0%) among older Chinese adults. Compared with the Progressively Mild Loss trajectory, the Progressively Severe Loss (ADL disability: OR=1.45, 95% CI: 1.15-1.84; IADL disability: OR=1.71, 95% CI: 1.47-1.99), Persistently Severe Loss (ADL disability: OR=2.33, 95% CI:1.93-2.82; IADL disability: OR=3.29, 95% CI: 2.82-3.84) and Edentulism (ADL disability: OR=3.25, 95% CI: 2.58-4.09; IADL disability: OR=3.60, 95% CI: 2.93-4.42) trajectories were significantly associated with an increased risk of functional disability with adjustment for potential confounders.

CONCLUSION

Four distinct tooth loss trajectories were identified among older adults and those with severe tooth loss trajectories had an increased risk of functional disability than those with a mild loss trajectory.

Impact of number of functional teeth on independence of Japanese older adults

AIM

To examine the relationship between the number of present and functional teeth at baseline and future incidence of loss of independence.

METHODS

Participants were community-dwelling older individuals who participated in a comprehensive geriatric health examination conducted in Kusatsu town, Japan, between 2009 and 2015. The primary endpoint was the incidence of loss of independence among participants, defined as the first certification of long-term care insurance in Japan. The numbers of present and functional teeth at baseline were determined via an oral examination. Demographics, clinical variables (e.g., history of chronic diseases and psychosocial factors), blood nutritional markers, physical functions, and perceived masticatory function were assessed.

RESULTS

This study included 1121 individuals, and 205 individuals suffered from loss of independence during the follow-up period. Kaplan-Meier estimates of loss of independence for participants with smaller numbers of present and functional teeth were significantly greater than for those with larger numbers of teeth. Cox proportional hazard analyses indicated that a smaller number of present teeth was not a significant risk factor after adjusting for demographic characteristics. However, the number of functional teeth was a significant risk factor after the adjustment (hazard ratio: 1.975 [1.168-3.340]). Additionally, higher hazard ratios were observed in other adjusted models, but they were not statistically significant.

CONCLUSIONS

The number of functional teeth may be more closely related to the future incidence of loss of independence than the number of present teeth. This novel finding suggests that prosthodontic rehabilitation for tooth loss possibly prevents the future incidence of this life-event. Geriatr Gerontol Int 2022; 22: 1032-1039.

Association between the number of remaining teeth and disability-free life expectancy, and the impact of oral self-care in older Japanese adults: a prospective cohort study

Background

Tooth loss has been reportedly associated with shorter disability-free life expectancy (DFLE). However, no study has explored whether oral self-care offsets reduction in DFLE. The present study aimed to assess the association between oral self-care and DFLE in older individuals with tooth loss.

Methods

Data on the 13-year follow-up from a cohort study of 14,206 older Japanese adults aged ≥ 65 years in 2006 were analyzed. Information on the number of remaining teeth was collected using a questionnaire, and the participants were then categorized into three groups (0–9, 10–19, and ≥ 20 teeth). Additionally, “0–9” and “10–19” groups were divided into two subgroups based on whether they practiced oral self-care. DFLE was defined as the average number of years a person could expect to live without disability, and was calculated by the multistate life table method based on a Markov model.

Results

DFLE (95% confidence interval) was 19.0 years (18.7–19.4) for 0–9 teeth, 20.1 (19.7–20.5) for 10–19 teeth, and 21.6 (21.2–21.9) for ≥ 20 teeth for men. For women, DFLE was 22.6 (22.3–22.9), 23.5 (23.1–23.8), and 24.7 (24.3–25.1), respectively. Practicing oral self-care was associated with longer DFLE, by 1.6–1.9 years with brushing ≥ 2 times a day in people with 0–9 and 10–19 teeth, and by 3.0–3.1 years with the use of dentures in those with 0–9 teeth.

Conclusions

Practicing oral self-care is associated with an increase in DFLE in older people with tooth loss.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03541-2.

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

INTRODUCTION

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Oral health problems and risk of incident disability in two studies of older adults in the United Kingdom and the United States

BACKGROUND

Preventing oral health problems can be crucial for maintaining physical independence in older adults. We aimed to examine the associations of a range of oral health problems with incidence of disability in older adults.

METHODS

We used prospective data from the British Regional Health Study (BRHS) (N = 2147, 71-92 years), and the Health, Aging and Body Composition (HABC) study (USA) (N = 3075, 71-80 years). Oral health measures included tooth loss, periodontal disease, self-rated oral health, and self-reported dry mouth. Participants were followed for onset of disability over a follow-up period of 3 years. Onset of disability was assessed through new cases of mobility limitations, activities of daily living (ADL), and instrumental activities of daily living (IADL). Logistic regression was performed to calculate the odds of incident disability.

RESULTS

In the BRHS, tooth loss was associated with greater odds of mobility limitations and ADL difficulties. Periodontal disease was associated with greater incidence of mobility limitations. Self-report of ≥3 dry mouth symptoms was associated with increased odds of incident mobility limitations and ADL difficulties (OR = 2.08, 95% CI 1.27-3.42; OR = 1.73, 95% CI 1.03-2.90). Fair/poor self-rated oral health was associated with greater incidence of IADL difficulties. In the HABC study, complete tooth loss was associated with greater incidence of mobility limitations (OR = 1.86, 95% CI 1.13-3.06), and fair/poor self-rated oral health was associated with increased odds of incident ADL difficulties (OR = 1.42, 95% CI 1.04-1.94).

CONCLUSIONS

Oral health problems in older adults, particularly tooth loss, self-reported dry mouth and self-rated oral health were associated with greater incidence of disability. Poor oral health plays a potentially important role in the development of disability in older populations, which in turn is an essential part of quality of life and healthy aging.

Tooth retention, health, and quality of life in older adults: a scoping review

OBJECTIVE

This scoping review describes the relationship between tooth retention, health, and quality of life in older adults.

METHODS

Seven databases were searched for English language articles for subjects ≥ 65 y from 1981 to 2021. Exposure was tooth retention (≥ 20), and outcomes were general/systemic health and quality of life. Methodological quality was assessed using the Newcastle-Ottawa Scale and Cochrane Risk of Bias 2.0 tool.

RESULTS

140 articles were included, only four were randomized trials. Inter-rater agreement (κ) regarding study inclusion was 0.924. Most were assessed with low risk of bias (n = 103) and of good quality (n = 96). Most studies were conducted in Japan (n = 60) and Europe (n = 51) and only nine in the US. Tooth retention was referred to as "functional dentition" in 132 studies and "shortened dental arch" in 19 studies. Study outcomes were broadly synthesized as (1) cognitive decline/functional dependence, (2) health status/chronic diseases, (3) nutrition, and (4) quality of life.

DISCUSSION

There is a positive relationship between tooth retention, overall health, and quality of life. Older adults retaining ≥ 20 teeth are less likely to experience poorer health. Having < 20 teeth increases the likelihood for functional dependence and onset of disability, and may affect successful ageing. This review supports the general finding that the more teeth older adults retain as they age, the less likely they are to have adverse health outcomes. However, significant knowledge gaps remain which can limit decision-making affecting successful ageing for many older adults. This review highlights the need to consider, as an important marker of oral health and function, the retention of a functional minimum of a natural dentition, rather than a simple numeric score of missing teeth.

Risk Factors of Long-Term Care Insurance Certification in Japan: A Scoping Review

This study aimed to review evidence on future long-term care associated with pre-existing factors among community-dwelling Japanese older adults. We systematically searched cohort and nested case–control studies published between 2000 and 2019 that assessed long-term care certification using the PubMed, CINAHL, and EMBASE databases. The relationship between long-term care insurance information and risk factors was investigated. The protocol was registered with the Open Science Framework. We extracted 91 studies for synthesis, including 84 prospective cohort studies, 1 retrospective cohort study, and 6 nested case–control studies. Certification for long-term care was classified into two endpoints: onset of functional disability and dementia. There were 72 studies that used long-term care certification as a proxy for functional disability, and 22 used long-term care information to indicate the onset of dementia. Common risk factors related to functional disability were physical function, frailty, and oral condition. Motor function and nutritional status were common risk factors for dementia. We found consistent associations between premorbid risk factors and functional disability and dementia. The accumulation of evidence on the incidence of long-term care and associated factors can aid the development of preventive measures. Future studies should aim to integrate this evidence.

Effects of tooth loss on functional impairment in elderly: a secondary data analysis of elderly cohort in the South Korea

INTRODUCTION

This study aimed to assess the association of tooth loss with physical and cognitive impairments in the elderly aged over 65 years.

METHODS

The Elderly Cohort database (2008-2013) of National Health Insurance Services in South Korea was used; 1,485 individuals who underwent physical impairment evaluation and 1,410 individuals who underwent cognitive impairment evaluation were analyzed. The dependent variables were the standardized physical and cognitive function score. The generalized estimating equation method was used for repeated measures. The total number of teeth lost during the study period, sex, age, Charlson Comorbidity Index, income, medical aid, long-term care facility residence, living alone, and long-term care beneficiary were used as covariates.

RESULTS

Differences between the baseline and endpoint standardized function scores of the participants with impaired physical function and impaired cognitive function were 13.6 and 20.1, respectively. The magnitude of functional impairment due to tooth loss was greater for cognitive function than for physical function. The number of teeth lost was associated with approximately 1.4- and 1.7-point decrease in physical and cognitive function, respectively (both p < 0.001).

CONCLUSIONS

These findings suggest that the oral health status is essential for maintaining physical and cognitive function and that oral health services can be effective in delaying functional impairment among the elderly residing in coordinated long-term care facilities.

Potential utility of physical function measures to improve the risk prediction of functional disability in community-dwelling older Japanese adults: a prospective study

Background

While gait speed, one-leg standing balance, and handgrip strength have been shown to be independent predictors for functional disability, it is unclear whether such simple measures of physical function contribute to improved risk prediction of functional disability in older adults.

Methods

A total of 1,591 adults aged ≥ 65 years and without functional disability at baseline were followed up for up to 7.9 years. Functional disability was identified using the database of Japan’s Long-term Care Insurance System. Maximum gait speed, one-leg standing time, and handgrip strength were measured at baseline. Cox proportional hazard models were used to estimate the hazard ratios (HRs) and 95 % confidence intervals (CIs) for the association of physical function and functional disability incidence. The incremental predictive value of each physical function measure for risk prediction was quantified using the difference in overall C-statistic, category-free net reclassification improvement (NRI), and integrated discrimination improvement (IDI) index.

Results

During follow-up (median: 7.8 years), functional disability was identified in 384 participants. All of the physical function measures were inversely associated with the risk of functional disability, independent of potential confounding factors. The multivariable adjusted HRs (95 % CIs) for functional disability per one standard deviation increment of maximum gait speed, one-leg-standing time, and hand grip strength were 0.73 (0.65–0.83), 0.68 (0.59–0.79), and 0.72 (0.59–0.86), respectively. Incorporation of each of maximum gait speed, one-leg-stand time, and hand grip strength into a basic model with other risk factors significantly improved C-statistic from 0.770 (95 % CIs, 0.751–0.794) to 0.778 (0.759–0.803), 0.782 (0.760–0.805), and 0.775 (0.756–0.800), respectively (all p < 0.05). A model including all three measures had the highest C-statistic of 0.787 (0.765–0.810). The improvements in risk prediction were also confirmed by category-free NRI and IDI index.

Conclusions

Adding any of the three measures to a basic model with other known risk factors significantly improved the prediction of functional disability and addition of all three measures provided further improvement of the prediction in older Japanese adults. These data provide robust evidence to support the practical utility of incorporating these simple physical function measures into functional disability risk prediction tools.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02415-3.

Influence of professional dental hygiene on oral and general health of retirement home residents: A comparative study

Objectives

The oral status of nursing home residents is poor. This could compromise general health. The controlled study investigated the influence of quarterly professional dental hygiene interventions on oral and general health of elderly.

Material and Methods

152 participants (mean age 84 years) of two residents' homes were examined. Parameters of general health, a questionnaire for caregivers, and oral parameters were evaluated at baseline and after 1 year. All caregivers were given one lesson on oral hygiene at baseline. In one home professional oral hygiene was performed every 3 months. Statistical analyses were done by Chi² test for nominal data and t‐test for numeric data.

Results

There were no significant differences between both homes regarding general health. Some oral parameters—if any—may be positively influenced by the intervention such as pocket depth, and Denture Hygiene Index and alterations of the mucosa.

Conclusions

A quarterly professional hygiene is not able to influence general health and has—if any—little effect on oral health. This underlines the necessity for frequent interventions. An optimization of the health policy framework is necessary to allow caregivers more time for oral hygiene and to establish the accessibility of frequent professional health care for inhabitants in residents' homes.

Home care aides' attitudes to training on oral health care

This study investigated home care aides' (HCAs) oral health care experience, knowledge, and their intention to receive professional training, to explain and predict factors of their intention to receive such training. This cross-sectional study collected data through a structured questionnaire. HCAs affiliated with home care agencies in Taichung, Taiwan were recruited through purposive sampling. A total of 487 questionnaires were distributed from September to December 2015 with 280 valid responses collected (57.4%).This study predicted the factors of HCAs' intention to receive oral health care training through a decision tree analysis. The decision tree model classified the respondents with an accuracy of 77.5%. The optimal predictor variable was oral health care knowledge (χ2 = 66.662, p < 0.0001). Among the low-scoring respondents on oral health care knowledge, 76.4% were classified in the "uninterested" group, whereas 84.8% of the high scorers were classified in the "interested" group. The second best predictor variable was whether oral health care is part of the job responsibility (χ2 = 7.979, p = 0.007). Among those who answered Yes, 92.9% were in the interested group, as were 76.5% of those who answered No. It is recommended to add "disease and oral care-related content" and "safety protection, assessment, and usage of oral care tools during practical oral care process" to the oral healthcare training course content for HCAs in order to improve HCAs' oral healthcare knowledge and oral care skills. These research findings are valuable and may be taken into account in the future development of the in-service educational training of oral healthcare for HCAs.

Relationship Between Oral Health and Fractures in Community-Dwelling Older Japanese Adults

OBJECTIVE

To investigate the relationship between poor oral health and the incidence of fall-related fractures in older Japanese individuals.

DESIGN

A 9-year prospective cohort study.

SETTING AND PARTICIPANTS

Participants comprised 937 community-dwelling older Japanese adults aged 70 years or older. They all lived in the Tsurugaya district, a suburban area of Sendai city, and underwent comprehensive geriatric assessment, including an oral examination, in a public facility.

MEASUREMENTS

The exposure variables were related to oral health status (posterior occlusal support, number of remaining teeth, and occlusal force). The outcome measure was the incidence of fall-related fractures, which was determined by National Health Insurance data. Analyzed covariates included age, sex, medical history, smoking, alcohol drinking, educational level, depressive symptoms, cognitive impairment, physical function, body mass index, and history of falls. Statistical relationships were examined by calculating hazard ratios (HRs) at 95% confidence intervals (CIs) using the Cox proportional hazard model.

RESULTS

In the multivariate analysis, the HRs of fall-related fractures were significantly higher in those with unilateral posterior occlusal support (HR, 2.72; 95% CI, 1.13-6.55) and no posterior occlusal support (HR, 2.58; 95% CI, 1.29-5.15) than in those with bilateral posterior occlusal support. The HRs (95% CIs) of fall-related fractures in individuals with 10-19 and 1-9 teeth and edentulous individuals were 1.77 (0.81-3.89), 2.67 (1.24-5.75), and 2.31 (1.01-5.28), respectively, compared to those with ≥20 teeth.

CONCLUSIONS AND IMPLICATIONS

Poor oral health status is a risk factor for the incidence of fall-related fractures in community-dwelling older Japanese individuals. The findings suggest that attention should be focused on oral health status to further understand the risk of fall-related fractures among community-dwelling older adults.

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

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

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

BACKGROUND AND AIM

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

PARTICIPANTS AND METHODS

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

RESULTS

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

CONCLUSION

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

Dentition status and 10-year higher-level functional capacity trajectories in older adults

AIM

The effect of dentition status on higher-level functional capacity patterns over time remains unclear. We aimed to identify distinct higher-level functional capacity trajectories in individuals aged 70-80 years, and examine whether dentition status at 70 years predicted the trajectory.

METHODS

The study included 551 community-dwelling adults aged 70 years at baseline. Higher-level functional capacity was measured using the Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-IC) up to the age of 80 years. A higher TMIG-IC score indicated a higher level of competence. Group-based trajectory modeling was used to identify distinct TMIG-IC trajectories. The number of teeth, use of dentures, sex and education were added as baseline group membership predictors. Dental visits, health behaviors, body mass index and comorbidities during observation were added as time-varying covariates.

RESULTS

Three TMIG-IC trajectories were identified: "high/stable" (65.3%), "middle/decline" (24.5%) and "low/decline" (10.2%). A lower number of teeth and non-denture use were associated with increased odds of a low/decline trajectory relative to a high/stable trajectory (odds ratio 1.09, 95% confidence interval 1.04-1.14 [per one decrease] and odds ratio 3.96, 95% confidence interval 1.54-10.16, respectively).

CONCLUSIONS

Older adults with fewer teeth and those without dentures at the age of 70 years were more likely to follow a trajectory toward functional decline with low baseline TMIG-IC scores, which further declines by the age of 80 years. These findings suggest that preserving natural teeth later in life, as well as using dentures, could contribute toward maintaining a higher-level functional competence. Geriatr Gerontol Int 2021; 21: 48-53.

Parity and Number of Teeth in Japanese Women: Results from the Japan Nurses' Health Study

Background: Parity is thought to be associated with a decreased number of teeth present in women. However, educational level and social status, which are particularly significant risk factors for loss of teeth, have been heterogeneous in previous observations. This cross-sectional survey aimed to clarify the associations of parity with the risk of having <20 teeth in Japanese female nurses participating in the Japan Nurses' Health Study (JNHS). Methods: In the third follow-up questionnaire of the JNHS, 11,299 women aged 27-82 years participated in this study. The number of participants according to age range was 7,225 (63.9%) aged <50 years and 4,074 (36.1%) aged ≥50 years. Information on parity and risk factors for loss of teeth was collected through a baseline questionnaire and then a follow-up questionnaire. Multivariate logistic regression analysis was used to calculate the adjusted odds ratio (OR) and 95% confidence interval (CI) of having <20 teeth according to parity category. Results: Participants ≥50 years who had experienced three or more deliveries had a significantly higher risk of having <20 teeth than those who had not experienced delivery (OR = 1.59, 95% CI = 1.14-2.20), although this finding was not observed in participants <50 years. In addition to parity, age and current smoking may be independent risk factors for having <20 teeth in Japanese nurses. Conclusions: Higher-parity female nurses ≥50 years may be more likely to lose teeth than those who have not experienced delivery.

Epidemiologic Research on Healthy Life Expectancy and Proposal for Its Extension: A Revised English Version of Japanese in the Journal of the Japan Medical Association 2019;148(9):1781-4

Healthy life expectancy is an indicator that represents a composite of data on mortality and health status and is defined as the average number of years that a person can expect to live at a certain level of health. To extend people's healthy life expectancy, my colleague and I conducted a variety of epidemiologic research based upon community-based cohort studies and intervention trials. The findings from our prospective cohort studies included blood pressure reference values measured at home, green tea health benefit, Japanese dietary pattern, and feeling ikigai (a sense of life worth living) at daily life. Based upon these evidence, I have made some proposals toward extension of healthy life expectancy. In 2011, as the Chair of the Planning Committee for the Next National Health Promotion of Ministry of Health, Labor and Welfare (MHLW), I proposed that the Health Japan 21 (second term) should aim to extend healthy life expectancy to exceed the number of years extended in the total life expectancy, thus compressing the duration to be spent in an unhealthy state (compression of morbidity). In the interim evaluation of the Health Japan 21 (second term) in 2018, we were able to demonstrate that this goal is being achieved. Compared with 2010, in 2016, the increase in healthy life expectancy (1.72 years in men and 1.17 years in women) was higher than that of total life expectancy (1.43 years in men and 0.84 years in women). As a result, the duration to be spent in an unhealthy state was reduced by 0.29 years in men and by 0.33 years in women. It is important to note that Japan is the only country that has made progress in achieving compression of morbidity at the national level. We need to maintain this momentum of compressing morbidity.

Regular dental visits may prevent severe functional disability: A community-based prospective study

BACKGROUND

Previous studies have shown that regular dental visits can affect the relationship of tooth loss with mortality and functional disability. However, the independent association between regular dental visits and incident functional disability is unclear.

METHODS

Our study participants were community-dwelling individuals aged ≥65 years, without disability at baseline. The outcome was the level of incident functional disability, as defined in a new certification of the public long-term care insurance. We defined no disability as no certification at follow-up, mild disability as support levels 1-2 and care level 1 (i.e., independent in basic ADL, but requiring some help in daily activities), and severe disability as care levels 2-5 (i.e., dependent in basic ADL). The exposure variable, based on the questionnaire, was regular dental visits at baseline. Covariates included gender, age, socio-economic status, health status, lifestyle habits, physical and mental functioning, and oral health variables. Using multinomial logistic regression, we calculated adjusted odds ratio (aOR) and 95 % confidence interval (CI) for mild disability and severe disability, with no disability as a reference category.

RESULTS

Among 8,877 participants, the 33-month cumulative incidence of mild and severe disability was 6.0 % and 1.8 %, respectively. After controlling for all covariates, regular dental visits at baseline were significantly associated with a lower risk of incident severe disability (aOR 0.65; 95 % CI, 0.46-0.91) but not the incidence of mild disability (aOR 0.96; 95 % CI, 0.79-1.17).

CONCLUSIONS

Encouraging dental visits may contribute to prevention of severe functional disability and extension of healthy life expectancy among community-dwelling older adults.

Association Between Dental Implants and Cognitive Function in Community-dwelling Older Adults in Korea

Objectives

This study aimed to evaluate the association between dental implants and cognitive function in community-dwelling older adults.

Methods

Data were collected from the baseline survey (2016-2017) of the Korean Frailty and Aging Cohort Study. The study sample comprised 1115 community-dwelling people aged 70 years to 84 years who had 0-19 natural teeth. Dental implants and natural teeth were identified by panoramic radiography, while the cognitive function was assessed by the Korean version of the Mini-Mental State Examination (MMSE-KC). The association between dental implants and cognitive function was analyzed by multiple linear regression. Sensitivity analysis was performed to test for potential bias.

Results

The mean number of natural teeth in the study population was 9.50 (standard deviation [SD], 6.42), and the mean MMSE-KC score was 24.93 (SD, 3.55). In the simple univariate analysis, tooth replacement, age, sex, smoking status, alcohol consumption, body mass index, osteoporosis, number of natural teeth, periodontitis, chewing discomfort, tooth-brushing frequency, education level, monthly household income, participation in economic activity, living alone, and marital status had a significant impact on the association. After adjusting for confounders, the association between dental implants and cognitive function remained significant (B, 0.85; standard error, 0.40; p<0.05). Age, body mass index, periodontitis, tooth-brushing frequency, and education level were also significantly associated with cognitive function. The results of the sensitivity analyses were consistent with those of the primary analysis.

Conclusions

Dental implants were associated with cognitive function in older adults living in the community. Dental implants as tooth replacements may play a role in preserving cognitive function.

Contribution of systemic inflammation and nutritional status to the relationship between tooth loss and mortality in a community-dwelling older Japanese population: a mediation analysis of data from the Tsurugaya project

OBJECTIVES

To assess whether systemic inflammation and nutritional status contribute to a relationship between tooth loss and mortality in community-dwelling older Japanese individuals using mediation analyses.

MATERIALS AND METHODS

This longitudinal study targeted community-dwelling older Japanese individuals (N = 891). The exposure variable was the number of teeth (edentulous, 1-9, 10-19, ≥ 20), while the outcome was all-cause mortality from 2003 to 2016. Nutritional status and systemic inflammation were evaluated as mediators and based on serum albumin and high-sensitivity C-reactive protein levels, respectively. Covariates included age, sex, smoking, alcohol consumption, medical history, educational level, depressive symptoms, cognitive impairment, and physical function. The Cox proportional hazards model was applied to calculate hazard ratios (HRs) for the association between tooth loss and mortality and the contributions of systemic inflammation and nutritional status to this association.

RESULTS

Edentulous participants (HR, 1.84; 95 % confidence interval [CI], 1.30-2.59) and those with 1-9 teeth (HR, 1.75; 95% CI, 1.28-2.40) groups exhibited a significantly higher risk of mortality than did those with ≥ 20 teeth. Mediation analyses showed that nutritional status contributed to the association between tooth loss and mortality in participants with 1-9 teeth, whereas systemic inflammation played no role in this association.

CONCLUSIONS

Nutritional status may contribute to the association between tooth loss and mortality in community-dwelling older Japanese individuals with fewer remaining teeth.

CLINICAL RELEVANCE

The data from this prospective cohort study help in elucidating parts of the biological mechanism underlying tooth loss and all-cause mortality in older individuals.

Oral Health, Disability and Physical Function: Results From Studies of Older People in the United Kingdom and United States of America

OBJECTIVES

Studies examining the associations between oral health and disability have limited oral health measures. We investigated the association of a range of objectively and subjectively assessed oral health markers with disability and physical function in older age.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional analyses were based on the British Regional Heart Study (BRHS) comprising men aged 71 to 92 years (n = 2147) from 24 British towns, and the Health, Aging, and Body Composition (HABC) Study comprising men and women aged 71 to 80 years (n = 3075) from the United States. Assessments included oral health (periodontal disease, tooth count, dry mouth, and self-rated oral health), disability, and physical function (grip strength, gait speed, and chair stand test).

RESULTS

In the BRHS, dry mouth, tooth loss, and cumulative oral health problems (≥3 problems) were associated with mobility limitations and problems with activities of daily living and instrumental activities of daily living; these remained significant after adjustment for confounding variables (for ≥3 dry mouth symptoms, odds ratio (OR) 2.68, 95% confidence interval (CI) 1.94-3.69; OR 1.76, 95% CI 1.15-2.69; OR 2.90, 95% CI 2.01, 4.18, respectively). Similar results were observed in the HABC Study. Dry mouth was associated with the slowest gait speed in the BRHS, and the weakest grip strength in the HABC Study (OR 1.75, 95% CI 1.22, 2.50; OR 2.43, 95% CI 1.47-4.01, respectively).

CONCLUSIONS AND IMPLICATIONS

Markers of poor oral health, particularly dry mouth, poor self-rated oral health, and the presence of more than 1 oral health problem, were associated with disability and poor physical function in older populations. Prospective investigations of these associations and underlying pathways are needed.

Age and female gender associated with periodontal disease in Japanese patients with rheumatoid arthritis: Results from self-reported questionnaires from the IORRA cohort study

Objectives: This study aimed to evaluate the prevalence of, and the factors associated with, periodontal disease in Japanese patients with rheumatoid arthritis (RA).Methods: Patients with RA enrolled in the Institute of Rheumatology Rheumatoid Arthritis (IORRA) cohort completed three self-administered questionnaires including questions about recent gingival bleeding during toothbrushing, a recent diagnosis of periodontitis by a dentist, and any history of periodontitis. Logistic regression analyses were used to evaluate associations with clinical variables for each questionnaire.Results: Among 5600 Japanese patients with RA, 31.0%, 18.3%, and 20.4% of patients self-reported recent gingival bleeding during toothbrushing, a recent diagnosis of periodontitis by a dentist, and a history of periodontitis, respectively. In multivariate models, younger age, fracture history, Japanese Health Assessment Questionnaire-Disability Index (JHAQ-DI), and prednisolone dosage were significantly (p < .05) associated with recent gingival bleeding during toothbrushing. Older age, female gender, and ever-smoker status were significantly correlated with a recent diagnosis of periodontitis.Conclusion: Many Japanese patients with RA experience gingival bleeding during toothbrushing and are diagnosed with periodontitis. Age, female gender, ever-smoker status, fracture history, JHAQ-DI, and prednisolone dosage appeared to be associated with periodontal disease in Japanese patients with RA.

The effect of missing teeth on dementia in older people: a nationwide population-based cohort study in South Korea

Background

To determine the effect of missing teeth on the risk of dementia onset among individuals who received tooth extractions and those who did not, based on the number of missing teeth.

Methods

We selected individuals who had not been diagnosed or treated for dementia between 2002 to 2011 from the National Health Insurance Service-Elderly Cohort Database (NHIS-ECD). We divided participants into two cohorts, a tooth extraction and non-extraction cohort, based on tooth loss from 2002 to 2011. After propensity score matching, there were 104,903 individuals in each cohort, and we included a total of 209,806 individuals in this study. Each cohort was grouped by sex, age, residential area, health insurance eligibility, income level, history of dental caries, history of periodontal treatment, and number of extracted teeth. We analyzed the relationship between dementia onset and these variables using logistic regression analysis.

Results

Individuals with tooth loss had a higher risk for dementia than those without tooth loss (odds ratio [OR] = 1.18; 95% confidence interval [CI]: 1.146–1.215). Regarding the incidence of dementia, the OR increased as the number of missing teeth and age increased, and the OR was higher for women (OR = 1.33; 95% CI: 1.286–1.367) than for men, and this difference was statistically significant (P < 0.01). The incidence of dementia decreased with periodontal treatment (OR = 0.96; 95% CI: 0.932–0.992) and increased with dental caries (OR = 1.07; 95% CI: 1.035–1.101).

Conclusions

These results suggest that it is important to delay tooth loss and preserve the stable remaining teeth to help prevent dementia.

Electronic supplementary material

The online version of this article (10.1186/s12903-019-0750-4) contains supplementary material, which is available to authorized users.

Periodontal complications with age

The present literature review on periodontal complications in aging focuses on the diagnosis, etiology and development of periodontal complications as a complete entity. In addition, the review also focuses on some of the common systemic diseases that either may further add to periodontal complications or, as result of anti-inflammatory treatment, limit the expression of periodontal disease. There is no evidence to suggest that clinical methods to provide periodontal therapies have been developed especially for older individuals. There is evidence that aging can be associated with periodontally healthy conditions through life and with a high level of tooth retention and function. Periodontal complications that are difficult to manage are usually associated with concurrent medical diseases and complications, or with socio-economic factors that limit the ability to provide dental care for the aging population. Currently, some systemic medical conditions are managed with anti-inflammatory medications with positive effects, while slowing the progression and expression of chronic periodontitis. The lack of data from clinical studies on how to manage periodontal complications in aging is obvious.

Dental Status is Associated With Incident Functional Disability in Community-Dwelling Older Japanese: A Prospective Cohort Study Using Propensity Score Matching

Background

A growing number of epidemiology studies have shown that poor oral health is associated with an increased incidence of functional disability. However, there are few studies in which the confounding bias is adjusted appropriately. In this study, we examined whether dental status is associated with functional disability in elderly Japanese using a 13-year prospective cohort study after elimination of confounding factors with propensity score matching.

Methods

Participants were community-dwelling Japanese aged 70 years or older who lived in the Tsurugaya district of Sendai (n = 838). The number of remaining teeth (over 20 teeth vs 0–19 teeth) was defined as the exposure variable. The outcome was the incidence of functional disability, defined as the first certification of long-term care insurance (LTCI) in Japan. The variables that were used to determine propensity score matching were age, sex, body mass index (BMI), medical history (stroke, hypertension, myocardial infarction, cancer, and diabetes), smoking, alcohol consumption, educational attainment, depression symptoms, cognitive impairment, physical function, social support, and marital status.

Results

As a result of the propensity score matching, 574 participants were selected. Participants with 0–19 teeth were more likely to develop functional disability than those with 20 or more teeth (hazard ratio 1.33; 95% confidence interval, 1.01–1.75).

Conclusions

In this prospective cohort study targeting community-dwelling older adults in Japan, having less than 20 teeth was confirmed to be an independent risk factor for functional disability even after conducting propensity score matching. This study supports previous publications showing that oral health is associated with functional disability.

Does Oral Health Predict Functional Status in Late Life? Findings From a National Sample

OBJECTIVE

This study aims to examine the association between oral health and the decline in functional status among middle-aged and older adults in the United States.

METHOD

Generalized estimation equation (GEE) Poisson regression models with robust standard errors were used to analyze the longitudinal panel data (2008-2014) from the Health and Retirement Study ( N = 1,243). Oral health was evaluated using self-rated oral health, poor mouth condition, and tooth loss. Decline in functional status was assessed by disabilities in activities of daily living (ADLs) and instrumental activities of daily living (IADLs).

RESULTS

Respondents with poor oral health were more likely to experience decline in ADLs/IADLs. Adjusting for sociodemographics and comorbidities attenuated the effects of oral health.

DISCUSSION

Findings suggest that oral health might be one of the important predictors of functioning decline in late life, after adjusting sociodemographics and comorbidities.

Relationship between status of dentition and incident functional disability in an elderly Japanese population: prospective cohort study of the Tsurugaya project

PURPOSE

The purpose of this study was to examine whether the status of dentition is associated with incident functional disability in elderly people.

METHODS

This prospective cohort study targeted community-dwelling Japanese adults of age ≥70 years (n=838). Participants were classified into the following four groups in accordance with Miyachi's Triangular Classification, which represents the status of dentition on the basis of numbers of remaining teeth and occlusal supports: Zone A, ≥10 occlusal supports; Zone B, 5-9 occlusal supports; Zone D, ≤4 occlusal supports and ≥11 remaining teeth and Zone C, ≤10 remaining teeth. Incident functional disability was defined by the first certification of long-term care insurance in Japan. Data regarding age, sex, body mass index, medical history, smoking, alcohol consumption, education, depressive symptoms, cognitive impairment, social support, history of fall, and subjective masticatory ability were collected.

RESULTS

During follow-up for 5185 person-years, 305 participants experienced functional disability. Considering the follow-up data of  ≥3 years from baseline, participants in Zones C (hazard ratio [HR], 1.98; 95 % confidence interval [CI], 1.26-3.11) and D (HR, 2.50; 95 %CI, 1.54-4.05) were found to be more likely to develop functional disability than those in Zone A (p for trend=0.002).

CONCLUSIONS

Status of dentition was associated with incident functional disability in an elderly Japanese population. The findings of this study suggest that maintenance of remaining teeth and retention of occlusal supports contribute to the prevention of functional disability.

Association between residual teeth number in later life and incidence of dementia: A systematic review and meta-analysis

Background

It has been suggested that tooth loss in later life might increase dementia incidence. The objective of this analysis is to systematically review the current evidence on the relationship between the number of remaining teeth and dementia occurrence in later life.

Methods

A search of multiple databases of scientific literature was conducted with relevant parameters for articles published up to March 25th, 2017. Multiple cohort studies that reported the incidence of dementia and residual teeth in later life were found with observation periods ranging from 2.4 to 32 years. Random-effects pooled odds ratios (OR) and 95% confidence intervals (CI) were estimated to examine whether high residual tooth number in later life was associated with a decreased risk of dementia. Heterogeneity was measured by I². The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system was used to assess the overall quality of evidence.

Results

The literature search initially yielded 419 articles and 11 studies (aged 52 to 75 at study enrollment, n = 28,894) were finally included for analysis. Compared to the low residual teeth number group, the high residual teeth number group was associated with a decreased risk of dementia by approximately 50% (pooled OR = 0.483; 95% CI 0.315 to 0.740; p < 0.001; I² = 92.421%). The overall quality of evidence, however, was rated as very low.

Conclusion

Despite limited scientific strength, the current meta-analysis reported that a higher number of residual teeth was associated with having a lower risk of dementia occurrence in later life.

Electronic supplementary material

The online version of this article (10.1186/s12877-018-0729-z) contains supplementary material, which is available to authorized users.

Impact of oral self-care on incident functional disability in elderly Japanese: the Ohsaki Cohort 2006 study

OBJECTIVES

To assess whether oral self-care (tooth brushing, regular dental visits and use of dentures) affects incident functional disability in elderly individuals with tooth loss.

DESIGN

A 5.7-year prospective cohort study.

SETTING

Ohsaki City, Japan.

PARTICIPANTS

12 370 community-dwelling individuals aged 65 years and older.

PRIMARY OUTCOME MEASURES

Incident functional disability (new long-term care insurance certification).

RESULTS

The 5.7-year incidence rate of disability was 18.8%. In comparison with participants who had ≥20 teeth, the HRs (95% CIs) for incident functional disability among participants who had 10-19 and 0-9 teeth were 1.15 (1.01-1.30) and 1.20 (1.07-1.34), respectively (p trend<0.05). However, the corresponding values for those who brushed their teeth ≥2 times per day were not significantly higher in the '10-19 teeth' and '0-9 teeth' groups (HRs (95% CI) 1.05 (0.91-1.21) for participants with 10-19 teeth, and 1.09 (0.96-1.23) for participants with 0-9 teeth), although HRs for those who brushed their teeth <2 times per day were significantly higher (HRs (95% CI) 1.32 (1.12-1.55) for participants with 10-19 teeth, and 1.33 (1.17-1.51) for participants with 0-9 teeth). Such a negating association was not observed for other forms of oral self-care.

CONCLUSIONS

Tooth brushing may partially negate the increased risk of incident functional disability associated with having fewer remaining teeth.