Association between Mixing Ability of Masticatory Functions Measured Using Color-Changing Chewing Gum and Frailty among Japanese Older Adults: The Kyoto-Kameoka Study

Accuracy of newly developed color determination application for masticatory performance: Evaluating color-changeable chewing gum

PURPOSE

Color-changeable chewing gums are used to evaluate masticatory performance, as measured by a colorimeter or visually based on a color scale. Although anyone can use a color scale, the evaluation accuracy depends on the evaluator. We develop an application that can determine the degree of color change in chewing gum using smartphone images, making color evaluation accurate and easy to measure.

METHODS

For the application, 60 chewed gum samples were prepared. Two shots were captured using two smartphone models. To create the application algorithm, a formula was developed to approximately map the color value from the smartphone images to the true value using a colorimeter. A basic validation was performed on 60 new samples covering a range of colors, followed by a field validation on 100 healthy dentate participants aged 20-39 years.

RESULTS

The intraclass correlation coefficient for two repeated shots had a high value ≥ 0.97 in the basic and field validations, confirming reliability. No significant differences were observed in the paired t-test and Wilcoxon signed-rank test, and a significant and strong correlation (correlation coefficient ≥ 0.92) was observed between the evaluation values using the colorimeter and the basic and field validations. Bland-Altman plots further confirmed the validity of the application.

CONCLUSIONS

A software application was developed to enable easy, quick, and accurate determination of the masticatory performance of a chewing gum from images taken using a smartphone with highly reliable and validated results.

Oral frailty is associated with mortality independently of physical and psychological frailty among older adults

BACKGROUND

Although oral frailty is independently associated with an increased risk of mortality, evidence for the usefulness of screening tools for oral frailty is less than that for physical frailty screening tools. We aimed to investigate the relationship between oral frailty and mortality in older adults.

METHODS

This prospective cohort study included 11,374 adults aged ≥65 years, who provided valid responses to a baseline mail survey questionnaire from the Kyoto-Kameoka study. Oral frailty status was evaluated using the Oral Frailty Index-8 (range, 0 [best] to 10 [worst]). Participants were classified into four categories according to the Oral Frailty Index-8: robust (score, 0-2), oral pre-frailty (score, 3), oral frailty (score, 4-6), and oral severe frailty (score ≥ 7). Physical and psychological frailty were evaluated using the validated frailty-screening index and defined as a score of ≥3 out of a possible 5 points. Mortality data were collected from 30 July 2011 to 30 November 2016. Hazard ratios (HR) for all-cause mortality were calculated using a multivariable Cox proportional hazards model.

RESULTS

During the 5.3-year median follow-up period (57,157 person-years), 1184 deaths were recorded. After adjusting for confounders, including physical and psychological frailty, medical history, and lifestyle, in comparison with a robust oral status, oral pre-frailty (HR, 1.29; 95 % confidence interval [CI], 1.02-1.63), oral frailty (HR, 1.22; 95 % CI, 1.01-1.48), and oral severe frailty (HR, 1.43; 95 % CI, 1.16-1.76) were associated with higher HRs of mortality (p for trend = 0.002).

CONCLUSION

Oral frailty is associated with mortality independent of physical and psychological frailty in older adults. The Oral Frailty Index-8 may be useful for identifying individuals at high risk of mortality.

Very old age impacts masticatory performance: a study among sexagenarians to centenarians

OBJECTIVE

This cross-sectional pilot study evaluated the impact of age on masticatory performance among individuals aged 65 to 106 years, as part of the Heidelberg Dental Centenarian Study (HD-100Z) conducted in South-Western Germany.

MATERIALS AND METHODS

A total of 31 centenarians were recruited, alongside 31 individuals each from the age groups 75-99 and 65-74, matched based on sex, prosthetic status, and number of teeth. Masticatory performance was assessed using a two-colored chewing gum test and digital image processing. Multiple linear regression analysis was performed to assess the effect of age, sex, number of teeth, type of prosthesis on the masticatory performance.

RESULTS

Masticatory performance, as measured by the standard deviation of hue in the chewing gum test, decreased significantly in centenarians compared to individuals aged 75-99 years (-0.112, p = 0.037) and those aged 65-74 years (-0.274, p < 0.001). The effects of sex, number of teeth, and type of prosthesis on masticatory performance were not significant associations (p ≥ 0.135).

CONCLUSION

The findings suggest that age may have a significant influence on masticatory performance in the studied age groups, challenging previous notions that aging itself has little impact on masticatory ability. The inclusion of centenarians in the study highlights the need for further investigation into masticatory function in age groups reaching up to 100 years or more.

CLINICAL RELEVANCE

This study contributes to the understanding of how ageing affects oral function, which may guide dental treatment approaches for older individuals, and set the stage for more in-depth investigations in this field in the future.

Physical frailty intensifies the positive association of oral frailty with poor global cognitive function and executive function among older adults especially for females: a cross-sectional study

BACKGROUND

Oral frailty is reported to increase the risk of new onset of mild cognitive impairment. Whereas, the association of oral frailty with cognition among older adults in both physical frail and non-physical frail status has not been sufficiently explored, and whether there are sex differences in the association is unclear. This study investigated the association of oral frailty and physical frailty with global cognitive function and executive function among older adults, as well as the sex differences in such association.

METHODS

This cross-sectional study included 307 participants aged ≥ 60 years old from communities between June 2023 and August 2023, in Nanjing, China. Global cognitive function and executive function were assessed by using the Montreal Cognitive Assessment (MoCA) and Trail Making Tests A (TMT-A), respectively. Oral frailty was identified by the combination of natural tooth, Oral Frailty Index-8 (OFI-8), and oral diadochokinesis. Physical frailty was measured by using Fried phenotype model which contained 5 criteria: unintentional weight loss, weakness, exhaustion, slowness, and low physical activity. Multiple linear regression analyses for overall participants and stratified by sex and presence or absence of physical frailty were performed, respectively, to examine the association between oral frailty and cognitive functions.

RESULTS

The median age of participants was 70 years old. The study included 158 (51.5%) females, 53 (17.3%) individuals with physical frailty, and 65 (21.2%) participants with oral frailty. After adjustment, the association between oral frailty and global cognitive function was observed in the physical frailty group (B = -2.67, 95% Confidence Interval [CI]: -5.27 to -0.07, p = 0.045) and the females with physical frailty (B = -4, 95% CI: -7.41 to -0.58, p = 0.024). Oral frailty was associated with executive function in overall participants (B = 0.12, 95% CI: 0.01 to 0.22, p = 0.037), physical frailty group (B = 23.68, 95% CI: 1.37 to 45.99, p = 0.038). In the adjusted models, oral frailty was significantly associated with executive function in all females (B = 0.21, 95% CI: 0.05 to 0.36, p = 0.009), in females without physical frailty (B = 0.19, 95% CI: 0.02 to 0.36, p = 0.027), and in females with physical frailty (B = 48.69, 95% CI: 7.17 to 90.21, p = 0.024).

CONCLUSIONS

Physical frailty intensifies the positive association of oral frailty with poor global cognitive function and executive function among older adults, particularly among females. It is ponderable to consider sex differences and facilitate the management of physical frailty when it comes to promoting cognitive health based on the perspective of oral health among older adults.

Thigh muscle thickness on ultrasonography for diagnosing sarcopenia: The Kyoto-Kameoka study

AIM

The Asian Working Group for Sarcopenia 2019 consensus reported that evidence for the diagnosis of sarcopenia based on ultrasonography findings is lacking. The revised European Working Group on Sarcopenia in Older People consensus stated that ultrasonography is reliable and valid for assessing muscle size in older adults. The present study aimed to determine the predictive accuracy of ultrasonography for sarcopenia in older adults in Japan.

METHODS

A total of 1229 participants aged 65-91 years were included in this cross-sectional study. The thickness of the anterior compartment of the right thigh was assessed using B-mode ultrasonography. The measurement position was at the midpoint of the thigh. In addition, the grip strength, gait speed, Five-Time Sit-to-Stand Test, Short Physical Performance Battery score and skeletal muscle mass index were evaluated. Sarcopenia was diagnosed based on the Asian Working Group for Sarcopenia 2019 algorithm. We calculated the area under the receiver operating characteristic curve.

RESULTS

The area under the receiver operating characteristic curves (95% confidence intervals) and cutoff values for the thigh muscle thickness in sarcopenia were 0.901 (0.856-0.946) and 4.0 cm in men, respectively, and 0.923 (0.851-0.995) and 3.1 cm in women, respectively. The area under the receiver operating characteristic curve for each subdomain of sarcopenia, such as grip strength and gait speed, ranged from 0.618 to 0.872.

CONCLUSIONS

In the present study, the suggested cutoff mid-thigh muscle thicknesses on ultrasonography for predicting sarcopenia were 4.0 cm in men and 3.1 cm in women. Geriatr Gerontol Int 2024; 24: 156-161.

Association between Masticatory Performance, Nutritional Intake, and Frailty in Japanese Older Adults

The older adult population in Japan is expected to increase. Therefore, long-term care and frailty prevention are important. However, the relationship between masticatory performance, nutritional intake, and frailty remains unclear. This cross-sectional study aimed to examine energy, protein, and vitamin D intake and its association with frailty and masticatory performance in older adults. Patients between January 2022 and January 2023 were recruited and divided into robust and frail groups. Masticatory performance, nutrition, frailty, and other data, such as age and sex, were evaluated through onsite measurements and a questionnaire. Logistic regression analysis was conducted with frailty as a dependent variable and masticatory performance as an independent variable, adjusting for age, sex, skeletal muscle mass, living alone, energy intake, protein-energy ratio, and vitamin D intake. No significant differences were observed between the groups regarding age or sex. The robust group showed significantly better results for protein-energy ratio, vitamin D intake, and subjective and objective masticatory performance than the frail group. Logistic regression analysis revealed a significant correlation between skeletal muscle mass, protein-energy ratio, and objective masticatory performance with frailty. Masticatory performance was associated with frailty, independent of the intake of nutrients such as energy, protein, and vitamin D.

Development of a multiple masticatory function model based on the evaluation of sarcopenia: A cross-sectional survey of the Otassha study

OBJECTIVE

The masticatory function is intricately linked to several factors like natural teeth count, occlusion, masticatory muscles, and tongue coordination. This study's goal was to formulate a comprehensive masticatory function model, considering sarcopenia's conceptual structure, and subsequently validate its measurement efficacy.

DESIGN

The study encompassed 753 participants (59.1 % women; mean age: 73.0 ± 5.1 years) from an urban community. The model amalgamated masseter muscle mass, occlusal force, and mixing ability. Based on the Asian Working Group for Sarcopenia 2019 classification, participants were categorized into a multiple masticatory dysfunction (MMD) or severe MMD (S-MMD) group. Logistic regression analysis gauged the model's validity, using serum albumin levels and self-reported chewing difficulties as dependent variables.

RESULTS

Of the total, 61 (8.1 %) participants exhibited MMD, while 24 (3.2 %) had S-MMD. S-MMD was correlated with low serum albumin levels (odds ratio: 3.62; 95 % confidence interval: 1.07-12.29) and heightened self-reported chewing difficulties (odds ratio: 2.82; 95 % confidence interval: 1.09-7.28).

CONCLUSIONS

Our multiple masticatory function model offers a straightforward approach for assessing MMD. Furthermore, the study establishes a link between S-MMD, nutritional vulnerability, and self-reported chewing challenges, thus affirming the model's credibility.

Chewing difficulty and frailty trajectories in Chinese nursing home residents: A prospective cohort study

AIM

To investigate frailty trajectories in nursing home residents, and to test whether chewing difficulty was a significant factor associated with frailty trajectories.

METHODS

This is a 1-year prospective cohort study. Data were collected from 27 nursing home residents in China at baseline, 6 months, and 12 months. Latent class growth modeling was used to identify frailty trajectories. Multilevel multinomial logistic regression was used to test the relative risk ratios (RRRs) with 95% confidence intervals (CIs) of the chewing difficulty assessed at baseline on frailty trajectories.

RESULTS

In total, 269 nursing home residents were included in the analysis. Three frailty trajectories identified were non-frailty trajectory (n = 181, 67.3%), stable frailty trajectory (n = 52, 19.3%), and progressive frailty trajectory (n = 36, 13.4%). Chewing difficulty was found among 138 (51.3%) nursing home residents. With the non-frailty trajectory group as the reference, residents with chewing difficulty were more likely to demonstrate stable frailty trajectory (RRR = 2.55, 95% CI [1.28-5.11]) or progressive frailty trajectory (RRR = 3.46, 95% CI [1.47-8.15]).

CONCLUSIONS

Changes in the frailty of nursing home residents are heterogeneous and chewing difficulty should be assessed and addressed on a routine basis in nursing homes to prevent the deterioration of frailty or reverse it. Geriatr Gerontol Int 2023; 23: 803-808.

A study on relationship between dynamic postural balance and masticatory efficiency in the elderly population with complete dentures: An in vivo study

Aim

Mastication is an important consideration for patients seeking prosthodontic treatment. Individuals with mastication problems have increased risk of systemic diseases which can negatively affect a person's postural balance control, which in turn increases the risk of falls. This study aims to correlate masticatory efficiency and dynamic postural balance in complete denture patients at 3 and 6 months after denture insertion.

Settings and Design

In vivo - observational study.

Materials and Methods

Fifty edentulous healthy patients were rehabilitated with conventional complete dentures. The dynamic postural balance was evaluated using the timed up-and-go test. The masticatory efficiency was evaluated using a color-changing chewing-gum and a color scale. The values for both were recorded 3 and 6 months after denture insertion.

Statistical Analysis Used

Spearman's correlation.

Results

The correlation between the values of dynamic postural balance and the values of masticatory efficiency was negative (values are inversely proportional) at 3 months (-0.379) and at 6 months (-0.246).

Conclusions

This study showed that there is a correlation between dynamic postural balance and masticatory efficiency. Prosthodontic rehabilitation of edentulous patients is important for improving postural balance by generating adequate postural reflex through mandibular stability for the prevention of falls in the elderly population and improving masticatory efficiency.

Combined use of two frailty tools in predicting mortality in older adults

We aimed to verify the combined use of two frailty tools in predicting mortality in older adults. We used the data of 10,276 Japanese older adults (aged ≥ 65 years) who provided valid responses to two frailty assessment tools in a mail survey in Japan's Kyoto‒Kameoka Prospective cohort study. Frailty status was categorized into four groups depending on the validated frailty screening index and Kihon Checklist, respectively: Non-frailty (n = 5960), Physical frailty (n = 223), Comprehensive frailty (n = 2211), and Combination (n = 1882) groups. Mortality data were collected between July 30, 2011, and November 30, 2016. We assessed the relationship between frailty status and all-cause mortality risk using multivariate Cox proportional hazards models. During a median follow-up of 5.3 years, we recorded 1257 deaths. After adjusting for confounders, the Combination group had the highest mortality risk compared with the other groups [Non-frailty: reference; Physical frailty: hazards ratio [HR], 0.99 (95% confidence interval [CI] 0.58 to 1.70); Comprehensive frailty: 1.91 (1.63 to 2.23); Combination: 2.85 (2.44 to 3.22)]. People who are positive for frailty in both instruments have a higher risk of death than those who are positive to one model.

Association between oral function and physical pre-frailty in community-dwelling older people: a cross-sectional study

BACKGROUND

Few studies have examined the relationship between oral functions and the physical pre-frailty status, classified using physical function tests. This cross-sectional study aimed to clarify this association among community-dwelling older people from the Itoshima Frail Study in Itoshima Fukuoka Prefecture.

METHODS

Of the 1,555 individuals invited to join the study, 381 (188 males and 193 females) enrolled. Their physical pre-frailty was assessed with a classification system consisting of two physical indicators (fatigue and unintentional weight loss, determined with a questionnaire), two functional components (declined walking speed and muscle weakness, determined using a body function measuring instrument), and declined physical activity (examined using a triaxial accelerometer). Subsequently, the individuals were classified into three groups: robust, pre-frailty, and frailty. Along with the number of teeth remaining, oral functions, such as masticatory performance, tongue pressure strength, and oral diadochokinesis (ODK), were examined. Data regarding social activity and exercise habits were collected, and the individuals' body compositions were measured. Odds ratios (ORs) and 95% confidence intervals (CIs) for the physical pre-frailty were calculated using logistic regression models.

RESULTS

In this study, 126 (33%) participants presented with physical pre-frailty. The participants in the robust group were younger, had stronger maximum handgrip strength, and walked faster than those in the physical pre-frailty group (p < 0.001). The robust group presented with better oral functions (masticatory performance, p = 0.015; oral ODK /ta/, p = 0.004). The physical pre-frailty status was significantly associated with age (OR, 1.111; 95% CI, 1.048-1.178; p < 0.001), masticatory performance (OR, 0.819; 95% CI, 0.680-0.986; p = 0.035), low ODK/ta/ (OR, 1.864; 95% CI, 1.069-3.250; p = 0.028), and low social activity (OR, 2.273; 95% CI, 1.308-3.951; p = 0.004).

CONCLUSION

This study indicated that older people with higher age, lower anterior tongue movement, lower masticatory performance, and lower social activity are positively associated with physical pre-frailty.

Adherence to the food-based Japanese dietary guidelines and prevalence of poor oral health-related quality of life among older Japanese adults in the Kyoto-Kameoka study

Although better diet quality is inversely related to the risk of geriatric disorders, the association of adherence to dietary guidelines with oral health-related quality of life (OHRQoL) is unclear. We aimed to investigate this association in older Japanese adults. This cross-sectional study included 7984 Japanese participants aged ≥ 65 years from the population-based Kyoto-Kameoka study. Dietary intake was estimated using a validated self-administered FFQ. The scores for adherence to the Japanese Food Guide Spinning Top (range: 0 (worst) to 80 (best)) were calculated. These scores were stratified into quartiles (Qs). Poor OHRQoL was defined as a score ≤ 50 using a 12-item Geriatric Oral Health Assessment Index. The OR and 95 % CI were calculated using multivariable logistic regression and the spline model. Higher adherence score was associated with a lower prevalence of poor OHRQoL (Q1-Q4:36·0 %, 32·1 %, 27·9 % and 25·1 %, respectively). An inverse association was found between the score for adherence to the food-based Japanese dietary guidelines and the OR of poor OHRQoL among all the participants (Q1: reference; Q2: OR, 0·87 (95 % CI: 0·75, 1·00); Q3: OR, 0·77 (95 % CI: 0·66, 0·90); Q4: OR, 0·72 (95 % CI: 0·62, 0·85); P_{for trend} < 0·001). These relationships were similar to the results in the spline model. Higher adherence to the food-based Japanese dietary guidelines is inversely associated with the prevalence of poor OHRQoL in older adults. Our results may provide useful insights to improve and maintain oral health.

Diet quality and physical or comprehensive frailty among older adults

PURPOSE

While the association between diet quality and mortality has been previously demonstrated, the association between frailty and diet quality has not been evaluated well. This study aimed to investigate the association between diet quality and prevalence of both physical and comprehensive frailty, using two validated tools, in a community-based cohort of older adults.

METHODS

We conducted cross-sectional analyses using baseline data of 7022 participants aged ≥ 65 years in the Kyoto-Kameoka study. Diet quality was assessed by calculating the adherence scores to the Japanese Food Guide Spinning Top using a validated questionnaire; the participants were stratified into quartile groups based on these scores. Physical and comprehensive frailty was assessed using the Fried phenotype model-based Frailty Screening Index and the Kihon Checklist, respectively. Multivariable logistic regression and the restricted cubic spline model were used to calculate odds ratios (ORs) and their 95% confidence intervals (CIs) for associations between adherence scores and frailty prevalence.

RESULTS

Higher adherence scores signified a higher intake of vitamin C, vegetables, dairy products, and fruits. Physical and comprehensive frailty prevalence was 14.2 and 35.8%, respectively. In a multivariable adjusted model, compared with the bottom adherence score quartile, the top quartile was associated with lower ORs of physical (OR 0.64; 95% CI 0.52-0.80) and comprehensive frailty (OR 0.60; 95% CI 0.51-0.71). These relationships were similar to results in the spline model.

CONCLUSIONS

This study shows an inverse dose-response relationship between diet quality and prevalence of both physical and comprehensive frailty in older adults.

Relationship between chewing ability and malnutrition, sarcopenia, and frailty in older adults

BACKGROUND

Several studies reported that impaired nutrition is associated with reduced muscle mass, muscle strength, and physical performance. Chewing ability is essential to maintain balanced oral nutrient intake. The study was designed to define the possible relationship between chewing ability and nutrition-related problems (malnutrition, sarcopenia, and frailty) in a holistic perspective.

METHODS

This cross-sectional study recruited adults aged ≥65 years. All patients were evaluated with comprehensive geriatric assessment. Sarcopenia was diagnosed according to European Working Group on Sarcopenia in Older People criterion. Malnutrition was determined according to body mass index, calf circumference, and Mini Nutritional Assessment short form (MNA-SF). Frailty status was diagnosed with the Clinical Frailty Scale. Masseter and gastrocnemius muscle thicknesses (MTs) were measured via ultrasonography imaging. Oral examinations were carried out by a dentist, and chewing performance was examined with a color-changeable chewing gum.

RESULTS

Overall, 135 older adults (76 females) were analyzed. Mean ± SD age was 75.7 ± 7.2 years; 37.0% of the patients were frail, 3.7% were malnourished, 12.6% were sarcopenic, and 20.0% had poor chewing function. In the poor chewing function group, age and frailty scores were increased and the MNA-SF scores, handgrip strength, skeletal muscle index, and masseter MT were reduced (all P < 0.05). After adjusting for confounders, regression analysis showed that low grip strength and low gastrocnemius MT were independently associated with poor chewing ability.

CONCLUSIONS

Chewing ability was related to sarcopenia. Age and low grip strength in females and low cognitive scores and having low gastrocnemius MT in males were independent variables affecting chewing ability.

Associations of general health conditions with masticatory performance and maximum bite force in older adults: A systematic review of cross-sectional studies

OBJECTIVES

To give an overview of the current evidence on the associations of general health conditions with masticatory performance and maximum bite force in older adults.

DATA/SOURCES

Three electronic databases (Medline via PubMed, Embase via Ovid and CINAHL Plus via EBSCOhost) were searched up to September 2021 for cross-sectional studies on general health conditions and masticatory performance or maximum bite force in older adults. Methodological quality of the included studies was independently evaluated based on Joanna Briggs Institute critical appraisal checklist for analytical cross-sectional studies. Data on the associations between general health conditions and masticatory performance or maximum bite force were extracted.

STUDY SELECTION

Of the 5133 records identified, 39 studies (43 articles) were included in this review. Significant negative associations were found between masticatory performance and stroke, sarcopenia, amyotrophic lateral sclerosis, chronic obstructive pulmonary disease, dyspepsia, dysphagia, anorexia, and carotid atherosclerosis. Significant negative association was found between maximum bite force and sarcopenia. There were equivocal results on the association between masticatory performance and diabetes mellitus, and between maximum bite force and stroke, and amyotrophic lateral sclerosis. There was no significant association between masticatory performance and metabolic syndrome, and between maximum bite force and progress of Parkinson's disease. Most studies revealed positive associations of physical function with masticatory performance and maximum bite force.

CONCLUSIONS

Negative associations between masticatory function of older adults and presence of several systemic diseases have been reported in a number of studies while there are positive associations between masticatory function and some physical function indicators.

CLINICAL SIGNIFICANCE

This study provides valuable information on the association of masticatory function with general health, which draws clinicians' attention to the masticatory function of older adults who suffer from certain systemic diseases or physical dysfunction, and to the need to improve their masticatory ability to achieve healthy aging.

Validation of the Kihon Checklist and the frailty screening index for frailty defined by the phenotype model in older Japanese adults

BACKGROUND

The term "frailty" might appear simple, but the methods used to assess it differ among studies. Consequently, there is inconsistency in the classification of frailty and predictive capacity depending on the frailty assessment method utilised. We aimed to examine the diagnostic accuracy of several screening tools for frailty defined by the phenotype model in older Japanese adults.

METHODS

This cross-sectional study included 1,306 older Japanese adults aged ≥ 65 years who underwent physical check-up by cluster random sampling as part of the Kyoto-Kameoka Study in Japan. We evaluated the diagnostic accuracy of several screening instruments for frailty using the revised Japanese version of the Cardiovascular Health Study criteria as the reference standard. These criteria are based on the Fried phenotype model and include five elements: unintentional weight loss, weakness (grip strength), exhaustion, slowness (normal gait speed), and low physical activity. The Kihon Checklist (KCL), frailty screening index (FSI), and self-reported health were evaluated using mailed surveys. We calculated the non-parametric area under the receiver operating characteristic curve (AUC ROC) for several screening tools against the reference standard.

RESULTS

The participants' mean (standard deviation) age was 72.8 (5.5) years. The prevalence of frailty based on the Fried phenotype model was 12.2% in women and 10.3% in men. The AUC ROC was 0.861 (95% confidence interval: 0.832-0.889) for KCL, 0.860 (0.831-0.889) for FSI, and 0.668 (0.629-0.707) for self-reported health. The cut-off for identifying frail individuals was ≥ 7 points in the KCL and ≥ 2 points in the FSI.

CONCLUSIONS

Our results indicated that the two instruments (KCL and FSI) had sufficient diagnostic accuracy for frailty based on the phenotype model for older Japanese adults. This may be useful for the early detection of frailty in high-risk older adults.

Screening for a Decreased Masticatory Function by a Color-changeable Chewing Gum Test in Patients with Metabolic Disease

Objective This study aimed to reveal the screening performance of a color-changeable chewing gum test for a decreased masticatory function in the assessment of oral hypofunction in patients with metabolic diseases. Methods We analyzed 1,000 patients with metabolic diseases, including diabetes, dyslipidemia, hypertension, and hyperuricemia. A decreased masticatory function was diagnosed by a gummy jelly test. Patients were asked to chew a test gum, which changed from green to red by thorough mastication, 60 times for 1 minute. The color change was visually evaluated using the color scale, from 1 (green-dominant) to 10 points (red-dominant), and was colorimetrically quantified as delta E in the L*a*b* color space. The screening performance for a decreased masticatory function was evaluated with the receiver operating characteristic (ROC) curve. Results Seventy-seven patients (7.7%) were diagnosed with a decreased masticatory function. The mean color scale and delta E of the gum test were 6.7±1.8 points and 42.9±6.7 units, respectively. The area under the ROC curve was 0.822 (95% confidence interval, 0.768-0.872) for the color scale and 0.838 (0.781-0.890) for delta E (p=0.41). The optimal cut-off point of the color scale was 5.5 (5.0-6.5) points, whereas that of delta E was 37.7 (35.5-38.8) units. The optimal cut-off points were not significantly different between the subgroups divided by clinical characteristics. Conclusions A color-changeable chewing gum test using the color scale as well as delta E would be a useful tool for screening patients with metabolic diseases for a decreased masticatory function in the assessment of oral hypofunction.

Sociomedical and oral factors affecting masticatory performance in an older population

OBJECTIVES

To assess the sociomedical and oral factors affecting masticatory performance in a community-dwelling older population.

MATERIALS AND METHODS

Community-dwelling persons over 60 years were investigated using medical and dental oral interviews, oral and denture examination (natural teeth, tooth mobility, number of occluding tooth pairs, and removable dentures' prevalence and quality), and evaluation of masticatory performance using a mixing ability test.

RESULTS

A total of 130 participants with a mean age of 73.9±8.5 years were recorded. Fifty-eight (44.6%) used various types of removable prostheses. Twenty were edentulous and used a pair of complete dentures. Univariate analyses revealed statistically significant associations (p≤0.05) between masticatory performance and aging, marital status, subjective chewing ability, use of removable dentures, use of various combinations of complete dentures, pain caused by maxillary denture, number of teeth, tooth mobility, posterior chewing pairs, all chewing contacts natural or prosthetic, retention of mandibular partial dentures, and dentures' occlusion. The multivariable quantile regression analysis revealed that fewer natural teeth (95% CI: -0.02-0.01, p<0.001), being edentulous and using a pair of complete dentures (95% CI: 0.09-0.35, p=0.001), and larger percentage of severely mobile teeth (95% CI: 0.07-0.82, p=0.020) were associated with lower masticatory performance.

CONCLUSIONS

Poor masticatory performance in older adults was associated with fewer teeth, being edentulous and using a pair of complete dentures, and increased prevalence of severe tooth mobility.

CLINICAL RELEVANCE

Retaining the natural dentition and preventing and treating periodontal disease are important measures to maintain masticatory performance in older adults.

The Significance of Posterior Occlusal Support of Teeth and Removable Prostheses in Oral Functions and Standing Motion

The purpose of this study was to evaluate the effect of posterior occlusal support of natural teeth and artificial teeth on oral functions and standing motion. Patients who had been treated with removable prostheses were enrolled as the subjects. Their systemic conditions (body mass index (BMI) and skeletal muscle mass index (SMI)) were recorded. The subjects were classified into two groups according to a modified Eichner index: B1-3 (with posterior occlusal support) and B4C (without posterior occlusal support). Maximum occlusal force (MOF), masticatory performance (MP), and standing motion (sway and strength) were evaluated for cases with and without removable prostheses. There were no significant differences in BMI and SMI between the B1-3 group and the B4C group. The subjects with removable prostheses demonstrated significantly higher values in MOF, MP, and sway and strength than the subjects without removable prostheses. The comparison of oral functions between the B1-3 group and the B4C group revealed that the positive effect of posterior occlusal support of natural teeth and removable prostheses and the significant positive effects of posterior occlusal support on standing motion were partly observed in these comparisons. Posterior occlusal support of natural teeth and even of removable prostheses may contribute to the enhancement of oral functions and standing motion.

Association of Oral Hypofunction with Frailty, Sarcopenia, and Mild Cognitive Impairment: A Cross-Sectional Study of Community-Dwelling Japanese Older Adults

Oral hypofunction is a new concept that addresses the oral function of older adults. Few studies have investigated the relationship between oral hypofunction and general health conditions such as frailty, sarcopenia, and mild cognitive impairment. This paper explores these relationships in a large-scale, cross-sectional cohort study. The relationships of oral hypofunction with frailty, sarcopenia, and mild cognitive impairment were examined using data from 832 individuals who participated in the 2018 health survey of the residents of Tarumizu City, Kagoshima Prefecture, Japan. Individuals with frailty, sarcopenia, and mild cognitive impairment had significantly higher rates of oral hypofunction. Frailty was independently associated with deterioration of the swallowing function (odds ratio 2.56; 95% confidence interval, 1.26-5.20), and mild cognitive impairment was independently associated with reduced occlusal force (odds ratio 1.48; 95% confidence interval, 1.05-2.08) and decreased tongue pressure (odds ratio 1.77; 95% confidence interval, 1.28-2.43). There was no independent association found between sarcopenia and oral function. In conclusion, early intervention for related factors such as deterioration of the swallowing function in frailty, reduced occlusal force, and decreased tongue pressure in mild cognitive impairment could lead to the prevention of general hypofunction in older adults.

Does Masticatory Ability Contribute to Nutritional Status in Older Individuals?

Mastication plays a primary role in the process of eating. Hence, compromised masticatory ability may affect the nutrition and quality of life, which are particularly important concerns among older individuals. It remains unclear how is the masticatory ability assessed regarding the nutritional status. We examined the effect of various oral factors on three masticatory ability tests conducted among older individuals. A total of 100 older individuals were enrolled in this study. Body mass index (BMI) as an indicator of nutritional status; and age, sex, and the number of occlusal and molar occlusal supports as clinical attributes were recorded. Three masticatory ability tests (masticatory efficiency, masticatory score, and satisfaction with mastication) were conducted, and tongue pressure, cheek pressure, and occlusal force were assessed as oral functions. A significant but weak correlation was found between masticatory efficiency and the masticatory score, but not between masticatory efficiency and satisfaction score. Objective masticatory efficiency was strongly associated with objective oral factors, whereas subjective assessments of masticatory ability (masticatory score and satisfaction score) were not. Furthermore, BMI was significantly associated with subjective assessments of masticatory ability but not with objective masticatory efficiency. Both subjective and objective assessments of masticatory ability, along with considerations of nutritional formulations, are required for the maintenance and improvement of nutritional status in older individuals.