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

OBJECTIVE: Although it has been suggested that a decline in oral function is one of the potential risk factors affecting mild cognitive impairment (MCI), evidence is insufficient to draw clear conclusions. This Japanese cross-sectional study examined the association between tongue pressure (TP) and MCI in middle-aged and older adults aged 36-84 years. METHODS: Study participants were 1019 (368 men and 651 women). TP was evaluated using a TP measurement device. The maximum value of three measurements was used for analysis. MCI was defined as being present if a participant had a Japanese version of the Montreal Cognitive Assessment score of <26. Adjustment was made for age, smoking status, alcohol consumption, leisure-time physical activity, body mass index, hypertension, dyslipidemia, diabetes mellitus, history of depression, number of teeth, employment, education, and household income. RESULTS: The prevalence of MCI was 45.3%. Among women, compared with the lowest tertile of TP, the second and highest tertiles were significantly associated with a lower prevalence of MCI with a clear dose-response relationship; the adjusted odds ratio (95% confidence intervals) in the second and highest tertiles of TP were 0.54 (0.36-0.83) and 0.55 (0.36-0.84), respectively (p for trend = 0.005). In contrast, no statistically significant association was observed between TP and the prevalence of MCI among men. CONCLUSIONS: Our findings suggest that higher TP might be inversely associated with the prevalence of MCI in middle-aged and older Japanese women.

Serum levels of vitamin D and periodontal inflammation in community-dwelling older Japanese adults: The Otassha Study.

AIM: To evaluate the association between vitamin D status and periodontal inflammation as determined by the periodontal inflamed surface area (PISA) in community-dwelling older adults. MATERIALS AND METHODS: This cross-sectional study included 467 Japanese adults (mean age = 73.1 years) who underwent full-mouth periodontal examinations and measurements of serum levels of 25-hydroxyvitamin D (25(OH)D). We used linear regression and restricted cubic spline models to analyse the association between exposure (serum 25(OH)D) and outcome (PISA). RESULTS: The linear regression model showed that, after adjusting for potential confounders, participants in the lowest quartile of serum 25(OH)D had 41.0 mm2 more PISA (95% confidence interval [CI]: 4.6-77.5) than the reference group (the highest quartile of serum 25(OH)D). The spline model showed that the association between serum 25(OH)D and PISA was non-linear and restricted to the low 25(OH)D range. PISA initially sharply decreased as serum 25(OH)D increased, and then the decreasing trend slowed and plateaued. The inflection point with the minimum PISA value was a serum 25(OH)D level of 27.1 ng/mL, above which there was no decreasing trend in PISA with increasing serum 25(OH)D levels. CONCLUSIONS: Low vitamin D status had an L-shaped association with periodontal inflammation in this cohort of Japanese adults.

Association between dry mouth and physical frailty among community-dwelling older adults in Japan: The Otassha Study.

OBJECTIVE: To elucidate the relationship between physical frailty and dry mouth among community-dwelling older adults in Japan. BACKGROUND: Oral hypofunction is associated with physical frailty in older adults. Dry mouth, subjectively evaluated as xerostomia and objectively measured as hyposalivation, is highly prevalent in older adults. However, few reports have used both measures of dry mouth and investigated their association with physical frailty. MATERIALS AND METHODS: This cross-sectional study included 643 individuals (mean age, 73.9 years) from the Otassha Study in 2019. Xerostomia was assessed using the 5-item Summated Xerostomia Inventory (SXI). Hyposalivation was assessed by measuring the amount of resting saliva using the modified cotton roll method. Frailty phenotypes were defined by weakness, slowness, weight loss, low physical activity level and exhaustion components, and served as the outcome variable. Participants with three or more components were considered physically frail, and those with one or two components were considered pre-frail. Ordinal logistic regression analyses were performed to evaluate the associations between physical frailty and xerostomia and hyposalivation. RESULTS: Among the participants, 4.5% and 49.8% had physical frailty and pre-frailty, respectively. In ordinal logistic regression analysis adjusted for demographic and health characteristics, the SXI score was associated with physical frailty status (adjusted odds ratio for a one-point increase in SXI, 1.12; 95% confidence interval, 1.06-1.19). However, no difference was observed between the amount of resting saliva and severity of physical frailty. CONCLUSION: Xerostomia is associated with physical frailty among community-dwelling older adults in Japan. CLINICAL TRIAL REGISTRATION: Not applicable.

Interrelationships among whole-body skeletal muscle mass, masseter muscle mass, oral function, and dentition status in older Japanese adults.

BACKGROUND: Generalized loss of skeletal muscle mass (SMM) may modulate or otherwise affect the loss of masseter muscle mass and be responsible for low masseter muscle performance and strength (i.e., low oral function). Moreover, dentition status can affect oral function independent of the muscle state. This cross-sectional study aimed to simultaneously investigate the relationships among whole-body SMM, masseter muscle mass, oral function (masseter muscle performance and strength), and dentition status in 1349 Japanese adults (mean age = 73.6 years). METHODS: We determined the estimated masseter muscle mass (e-MMM) based on morphological measurements of the masseter muscle. Masseter muscle performance was assessed via masticatory performance evaluation scores using gum, and strength was assessed as the maximal occlusal force. Dentition status was assessed as the number of functional teeth. SMM was measured by bioelectrical impedance analysis. Structural equation modeling stratified by sex was employed to investigate associations among SMM, e-MMM, gum score, occlusal force, and number of functional teeth. RESULTS: The direct path from SMM to e-MMM was statistically significant, as was the direct path from e-MMM to oral function (gum score and maximum occlusal force) for both sexes. We additionally confirmed that SMM indirectly affected gum score and maximum occlusal force via e-MMM (men; standardized coefficient [95% CI] = 3.64 [1.31 to 5.96] for maximum occlusal force and 0.01 [0.01 to 0.02] for gum score, women; 2.01 [0.38 to 3.81] for maximum occlusal force and 0.01 [0.002 to 0.01] for gum score). The number of functional teeth had direct effects on e-MMM, gum score, and maximum occlusal force. CONCLUSIONS: Low SMM was significantly indirectly associated with poor oral function through a low masseter muscle mass, and dentition status was independently associated with oral function.

[The oral function of community-dwelling older adults complaining of an oral function deterioration: An examination using the oral function-related items of the Questionnaire for Latter-stage Elderly People].

AIM: The oral function-related items of the newly developed "Questionnaire for Latter-stage Elderly People" are based on two items of the Kihon checklist assessing the masticatory and swallowing functions. In this study, we estimated the questionnaire's application rate and investigated the oral function of the respondents. METHODS: Included were 699 older adults (274 men/425 women, average age, 73.4±6.6 years old). Those who responded positively to the related items were considered to have decreased swallowing and masticatory functions. The specific oral function was assessed based on the number of present and functional teeth; oral hygiene; oral moisture; occlusal force; oral diadochokinesis /pa/, /ta/, /ka/; tongue pressure; mixing ability; shearing ability; and Eating Assessment Tool (EAT)-10 (reference, score ≥3). RESULTS: The rates of decreased masticatory and swallowing functions were 21.5% and 26.6%, respectively, while 7.4% of participants had both. Those with a decreased masticatory function showed fewer present teeth; a lower occlusal force, oral diadochokinesis /pa/, mixing ability, shearing ability, and higher EAT-10 scores.Those with a decreased swallowing function only had higher EAT-10 scores. In the early- and latter-stage elderly, the decreased masticatory function rates were 15.6% and 29.4%, respectively, the decreased swallowing function rates were 27.8% and 25.0%, respectively, and the rates of both decreased masticatory and swallowing functions were 6.0% and 9.5%, respectively. CONCLUSION: The older adults who responded positively to the related questionnaire items, especially for items related to masticatory function, had a decreased oral function in multiple respects. The items related to the oral function in the Questionnaire for Latter-stage Elderly People are considered useful for identifying older adults with a decreased oral function.

Association between anorexia and hyposalivation in community-dwelling older adults in Japan: a 6-year longitudinal study.

BACKGROUND: Hyposalivation is associated with the nutritional status. Anorexia of ageing, defined as an age-related decrease in appetite and food intake, presents even in healthy adults and is considered an independent predictor of malnutrition, frailty, and mortality. However, the relationship between anorexia and hyposalivation of ageing is unclear. Thus, the present longitudinal study aimed to investigate the incidence of hyposalivation and its relationship with anorexia in community-dwelling older people in Japan. METHODS: The study population comprised 220 individuals (80 men and 140 women) aged 65-86 years at baseline. The participants underwent comprehensive health check-ups, including dental examinations and anthropometry, and face-to-face interviews in 2013 and 2019. Hyposalivation was determined on the basis of the unstimulated salivary flow rate measured using the modified cotton roll method. Anorexia was defined as a score of ≤29 in the Japanese version of the Council on Nutrition Appetite Questionnaire. Logistic regression analyses were used to test whether the presence of anorexia at baseline was an independent predictor of hyposalivation. RESULTS: Hyposalivation developed at a rate of 19.5% during the 6-year observation period. Anorexia was observed in 95 (43.2%) participants at baseline. After adjusting for potential confounding factors, anorexia (adjusted odds ratio [AOR], 2.65; 95% confidence interval [CI], 1.26-5.57) and polypharmacy (AOR, 3.29; CI, 1.06-10.19) were significant predictors of hyposalivation. CONCLUSION: Loss of appetite is independently correlated with and a risk factor for hyposalivation in older adults. Anorexia of ageing may have negative effects on the salivary flow rate in such settings. Salivation should be a standard feature in clinical assessments of the older adults.

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.

Validation of self-reported articulatory oral motor skill against objectively measured repetitive articulatory rate in community-dwelling older Japanese adults: The Otassha Study.

AIM: To assess the validity of self-reported articulatory oral motor skill against objectively measured repetitive articulatory rate (oral diadochokinesis [oral-DDK]) as a gold standard index for articulatory oral motor skill in community-dwelling older Japanese adults. METHODS: This cross-sectional study included 607 Japanese adults (mean age = 73.9 years). A single-item self-report questionnaire for articulatory oral motor skill was developed. Study participants completed a 1-month-interval test-retest protocol to assess reliability of the questionnaire, and the protocol was tested by the kappa statistic. Oral-DDK with /ta/ (i.e., the number of repetitions of the monosyllable /ta/ per second) was measured during the on-site examination. Low oral-DDK performance was defined as <5.2 times/s in men and <5.4 times/s in women. Oral-DDK performance, oral functions other than articulatory oral motor skill, and physical frailty were compared in the groups with and without self-reported low articulatory oral motor skill as determined by the response to the questionnaire. RESULTS: Self-reported low articulatory oral motor skill was identified in 18.5% of the study population. The self-report questionnaire had good test-retest reliability, with a kappa statistic of 0.71. Self-reported low articulatory oral motor skill was significantly associated with a lower value of oral-DDK with /ta/ and a higher proportion of low oral-DDK performance, difficulties in chewing and swallowing, dry mouth, and physical frailty. Self-report had high specificity (83.1%) but low sensitivity (42.1%) for detecting low oral-DDK performance. CONCLUSIONS: A single-item self-report questionnaire for articulatory oral motor skill had acceptable test-retest reliability and was associated with objectively measured articulatory oral motor skill. Geriatr Gerontol Int 2023; 23: 729-735.

Association between sarcopenia and oral functions in community-dwelling older adults: A cross-sectional study.

BACKGROUND: Few studies have examined the state of oral function in older adults with sarcopenia. We assessed the oral functions of community-dwelling older adults with sarcopenia from multiple perspectives to clarify their potentially low oral function. METHODS: A total of 1517 (86.2%; 990 women, 527 men; mean age 76.1 ± 7.6 years) participants were included in this study. Grip strength, gait speed and skeletal muscle mass index were assessed, and sarcopenia was evaluated according to the criteria of the Asian Working Group for Sarcopenia 2019. The degree of tongue coating, oral moisture, occlusal force, tongue-lip motor function, tongue pressure, masticatory function and swallowing function were assessed. The criteria for oral hypofunction (a disease that is a combination of multiple low oral functions) were used to assess oral function. Statistical analyses were performed using Kolmogorov-Smirnov test, unpaired t-test, Mann-Whitney U test, χ2 test, and univariate and multivariable logistic regression analyses, with each oral function as the dependent variable and sarcopenia as one of the independent variables. The significance level was set at P < 0.05. RESULTS: The prevalence rates of sarcopenia and severe sarcopenia were 14.2% and 3.8%, respectively. The prevalence of oral hypofunction was 39.9%. Compared with the robust group, the sarcopenia and severe sarcopenia groups tended to have a higher frequency of the following components (all P < 0.01): low occlusal force, low tongue-lip motor function, low tongue pressure, low masticatory function, low swallowing function and oral hypofunction. Univariate logistic regression analysis showed that sarcopenia was associated with low occlusal force, low tongue-lip motor function, low tongue pressure, low masticatory function, low swallowing function and oral hypofunction. The odds ratios and 95% confidence intervals of sarcopenia for each oral function were 2.62 [2.00, 3.43], 2.21 [1.69, 2.89], 3.66 [2.79, 4.81], 3.23 [2.46, 4.25], 1.66 [1.26, 2.20] and 3.59 [2.72, 4.72], respectively. Multivariable logistic regression analysis showed that sarcopenia was associated with low occlusal force (1.63 [1.10, 2.40]), low tongue pressure (2.28 [1.65, 3.15]), low masticatory function, (1.94 [1.27, 2.97]), low swallowing function (1.64 [1.17, 2.28]) and oral hypofunction (2.17 [1.52, 3.09]). CONCLUSIONS: This study demonstrated that multiple aspects of oral function were low among community-dwelling older adults with sarcopenia. The potential decline in oral functions in older adults with sarcopenia may have been overlooked until now. This study indicates the need for dental perspectives in intervening with older adults with sarcopenia and the need to encourage them to see dental professionals.

Standard Values and Concurrent Validity of a Newly Developed Occlusal Force-Measuring Device among Community-Dwelling Older Adults: The Otassha Study.

Recently, an occlusal force-measuring device with a capacitive-type pressure-mapping sensor (OFMD-CPS) was developed. We aimed to establish age- and sex-specific standard values for OFMD-CPS-measured occlusal force (OF) and to assess the concurrent validity of the OFMD against another OF measuring system with a pressure-sensitive sheet (Dental Prescale II). Using data from a population-based study, we calculated the OFMD-CPS-measured OF means and deciles in 5-year age groups for each sex. The OFMD-CPS-measured OF was validated against the Dental Prescale II-measured OF with Spearman correlation coefficients. Furthermore, we calculated the area under the receiver operating characteristic curve (AUC) against the preexisting Dental Prescale II-measured OF cutoff value of 350 N. In total, 596 individuals (236 men and 360 women) with a mean (standard deviation (SD)) age of 73.7 (6.7) years were included in the analyses. The mean (SD) OFMD-CPS-measured OFs were 581.6 (284.6) N in men and 446.9 (209.9) N in women. There was a strong positive correlation (Spearman's Rho = 0.73) between OFMD-CPS-measured and Dental Prescale II-measured OF. The diagnostic accuracy of the OFMD-CPS-measured OF for the Dental Prescale II-measured OF cutoff value was high (AUC = 0.88). In conclusion, we demonstrated standard values and concurrent validity of OFMD-CPS-measured OF in community-dwelling older adults.

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.

Effect of oral health intervention on cognitive decline in community-dwelling older adults: A randomized controlled trial.

PURPOSE: The incidence of dementia is rapidly increasing worldwide, especially in developed countries. Little is known regarding the effectiveness of dental intervention to prevent dementia or a decline in cognitive functions among community-dwelling older adults, but a few studies have reported a correlation between the lack of regular dental checkups and dementia. For that reason, this study aimed to investigate the effects of oral health intervention on cognitive functions in community-dwelling subjects with a mild cognitive decline via a randomized controlled trial. PATIENTS AND METHODS: Fifty-five community-dwelling older adults with a Mini-Mental State Examination score of ≥21 to ≤26 who had not visited a dental clinic in the previous year were randomized to an intervention group (n = 28) or a control group (n = 29). The intervention group received monthly oral health intervention by dental hygienists for 8 months while the control group did not. Data on demographics, cognitive function and oral parameters were collected before and after the intervention. RESULTS: Twenty-five subjects in the intervention group (mean age 77.0 years) and 25 in the control group (mean age 72.8 years) completed the study. Significant improvements were observed in the Trail Making Test (TMT)-A, TMT-B, bleeding on probing rate, oral diadochokinesis, tongue pressure and chewing ability in the intervention group (P < 0.05). There were also significant interactions between the TMT-A and TMT-B scores, oral diadochokinesis, tongue pressure and chewing ability (P < 0.05). CONCLUSION: Oral health intervention by dental hygienists may be effective for improving the oral health and executive function of cognitive function assessed via TMT.

Relationship between Chewing Ability and Nutritional Status in Japanese Older Adults: A Cross-Sectional Study.

OBJECTIVES: This study aimed to determine the relationship between objective chewing ability and the nutritional status of Japanese community-dwelling elders. DESIGN: A cross-sectional study. PARTICIPANTS: A total of 509 community-dwelling elders living in the Tokyo metropolitan area participated in a comprehensive survey conducted in October 2013. MEASUREMENTS: The basic characteristics were sex, age, and body mass index. Undernutrition was examined through serum albumin levels. Chewing ability was examined through color-changeable xylitol gum by evaluating the color changes in chewing gum. Nutritional intake was examined using the semi-quantitative food frequency questionnaire. RESULTS: In the poor chewing ability group, all nutrient intake levels were significantly low, except for carbohydrates, and intake levels for all food groups were significantly low, except for cereals, confectionery, sugars, seasonings, and spices. Additionally, after adjusting for covariates for sex, age, Tokyo Metropolitan Institute of Gerontology-Index of Competence (TMIG-IC) score, Mini-Mental State Examination (MMSE) score, body mass index (BMI), stroke, number of functional teeth, energy intake, and protein intake, chewing ability was found to be significantly associated with undernutrition. CONCLUSION: We concluded that chewing ability was closely associated with nutrient and different food groups' intake, as well as undernutrition, among Japanese community-dwelling elders. Thus, to ensure comprehensive nutritional management, nutritionists and dentists should collaborate when treating the same patients.

Number of functional teeth more strongly predicts all-cause mortality than number of present teeth in Japanese older adults.

AIM: Previous studies on the association between intraoral conditions and mortality in community-dwelling older individuals reported that fewer present teeth (PT) are significant risk factors for mortality. However, how the number of PT relative to the number of functional teeth (FT), including both present and rehabilitated teeth, influences mortality has not been investigated fully. This study examined the impact of the number of FT on mortality among community-dwelling Japanese older adults. METHODS: This study was a retrospective, observational and population-based follow-up study, which examined 1188 older individuals who participated in an annual geriatric health examination from 2009 to 2015. The average follow-up period was 1697.0 ± 774.5 days. The primary outcome was all-cause mortality at follow-up. The numbers of PT and FT of each participant were counted during an oral examination. In addition, demographics, clinical variables, blood nutrient markers, physical functions and perceived masticatory function were measured. RESULTS: Kaplan-Meier analysis, followed by a log-rank test, revealed that fewer PT (P < 0.001) and FT (P = 0.002) were significantly associated with a reduced survival rate. Cox's proportional hazard analysis indicated that the number of FT, but not the number of PT, was a significant independent mortality risk factor after adjusting for demographics, clinical variables, nutrient markers and physical functioning (P = 0.036, hazard ratio: 2.089). CONCLUSIONS: Current results suggest that the number of FT more strongly predicts all-cause mortality than the number of PT among community-dwelling older adults. Further studies are necessary to consider the confounding of socioeconomic status and disability status. Geriatr Gerontol Int 2020; ••: ••-••.

Association between decrease in frequency of going out and oral function in older adults living in major urban areas.

AIM: To examine the association between a decrease in the frequency of going out and oral function in independent older adults living in the urban area of Tokyo. METHODS: The participants analyzed were 785 older adults from the "Takashimadaira Study" (344 men and 441 women, age 77.0 ± 4.6 years). This study investigated the following items: decrease in frequency of going out; basic characteristics (sex, age); physical factors, such as oral function (difficulty chewing, difficulty swallowing, dry mouth); body pain; the Japan Science and Technology Agency Index of Competence; physical activities; psychological factors, such as the Geriatric Depression Scale-15 score; and social and environmental factors, such as the presence or absence of participation in organization activities. RESULTS: To investigate the factors associated with a decrease in frequency of going out, logistic regression analysis showed an association with age (OR 1.08, 95% CI 1.03-1.13), difficulty chewing (OR 2.41, 95% CI 1.52-3.83), dry mouth (OR 1.68, 95% CI 1.07-2.64), body pain (OR 1.78, 95% CI 1.14-2.78), Japan Science and Technology Agency Index of Competence scores (OR 0.91, 95% CI 0.84-0.99), physical activities (OR 0.99, 95% CI 0.98-1.00), Geriatric Depression Scale-15 scores (OR 1.13, 95% CI 1.05-1.21) and organization activities (OR 1.94, 95% CI 1.22-3.07). Covariance structural analyses showed that both "difficulty chewing" and "dry mouth" significantly affected "decrease in frequency of going out." In addition, decrease in frequency of going out was significantly affected by " Geriatric Depression Scale-15 scores" through oral function. CONCLUSIONS: The relationship between oral function and decrease in frequency of going out was clarified, after the multifaceted factors were adjusted. Geriatr Gerontol Int 2019; 19: 792-797.

Relation between knee extension torque and occlusal force in community-dwelling elderly adults.

The relation between occlusal force and general motor ability induced by lower-limb musculature is unclear. To identify indicators of oral and lower-limb muscle weakness, this study examined the relation between masticatory muscle strength and lower limb muscle force in 742 community-dwelling elderly adults (315 men and 427 women, mean age 73.3 ± 5.5 years) living in Itabashi ward, Tokyo. Multiple regression analysis of the relation between occlusal force and knee extension torque, in relation to age and sex, showed a significant correlation between the two variables (r = 0.348, P < 0.001), which indicates that occlusal force is a determinant of knee extension torque. Occlusal force remained significantly correlated with knee extension torque after adjustment for factors known to be related to the latter. In conclusion, chewing function and lower-limb motor function were significantly correlated and thus might be indicators of muscle weakness in elderly adults.

Factors associated with self-rated oral health among community-dwelling older Japanese: A cross-sectional study.

OBJECTIVES: A cross-sectional study was carried out to investigate the determinants of self-rated oral health among community-dwelling older people in Japan. METHODS: The participants were 897 (357 men and 540 women) aged 65 years and over who participated in a comprehensive geriatric health examination, which included an oral examination, a face-to-face interview assessing cognitive function, questionnaires regarding depressive symptoms and functional capacity, and a medical examination. The oral examination measured indices of oral health status: number of present teeth, number of functional teeth, occlusal force and amount of resting saliva. Multiple logistic regression analyses were carried out to determine the factors associated with poor self-rated oral health. RESULTS: The mean age of the participants was 73.5 ± 5.0 years. The prevalence of poor and rather poor self-rated oral health was 11.5% and 29.5%, respectively. Multiple logistic regression analyses showed that the number of present teeth (odds ratio [OR] 0.97, 95% confidence intervals [CI] 0.95-0.99), difficulty in mastication (OR 3.20, CI 2.18-4.70), presence of xerostomia (OR 1.43, CI 1.02-2.01), total score on the MoCA-J (OR 1.06, CI 1.01-1.11), and reduction in frequency of leaving the house (OR 1.64, CI 1.12-2.41) were significantly associated with poor self-rated oral health. CONCLUSIONS: The present results suggested that self-rated oral health was a significant factor in oral health status as well as overall well-being among community-dwelling older Japanese people.