Yusuke Mihara

Age and sex differences in the taste sensitivity of young adult, young-old and old-old Japanese

The present study examined sex and age differences in taste sensitivity among young adult, young‐old and old‐old Japanese.

Association of periodontal status with occlusal force and food acceptability in 70-year-old adults: From SONIC Study

This cross-sectional study aimed to investigate the association of periodontal status with occlusal force and food acceptability. We hypothesised that mastication deteriorated with reduced periodontal support, even when posterior occlusal contacts with natural teeth were maintained and the patients remained clinically asymptomatic. Participants were 482 independently living 69-71-year-olds, classified as Eichners group A, having no mobile teeth and no periodontal symptoms. The periodontal probing depth (PPD) and restoration status of each tooth were examined. Occlusal force in the intercuspal position was measured with pressure-sensitive films. Food acceptability was evaluated from the difficulty experienced in chewing apples, grilled beef, and hard rice crackers. Multivariate regression analysis was performed to investigate the association of periodontal status with occlusal force and food acceptability. A P-value of <0.05 was considered statistically significant. Multiple linear regression analysis showed that occlusal force had significant negative associations with maximal PPD (standardised partial regression coefficient (β) = -0.121) after controlling for gender, handgrip strength, number of teeth, and percentage of restored teeth. Approximately 15% of participants were included in the compromised food acceptability group. Logistic regression analyses showed that compromised food acceptability was significantly associated with PPD, after controlling for gender, number of teeth, and percentage of restored teeth. Periodontal probing depth (PPD) was significantly correlated with occlusal force and self-rated food acceptability after controlling for the possible confounding factors in septuagenarians, even those with complete posterior occlusal contacts and no tooth mobility.

Factors related to taste sensitivity in elderly: cross-sectional findings from SONIC Study.

The sense of taste is important, as it allows for assessment of nutritional value, as well as safety and quality of foods, with several factors suggested to be associated with taste sensitivity. However, comprehensive variables regarding taste and related factors have not been utilised in previous studies for assessments of sensitivity. In the present study, we performed cross-sectional analyses of taste sensitivity and related factors in geriatric individuals who participated in the SONIC Study. We analysed 2 groups divided by age, 69-71 years (young-old, n = 687) and 79-81 years (old-old, n = 621), and performed a general health assessment, an oral examination and determination of taste sensitivity. Contributing variables were selected by univariate analysis and then subjected to multivariate logistic regression analysis. In both groups, females showed significantly better sensitivity for bitter and sour tastes. Additionally, higher cognitive scores for subjects with a fine taste for salty were commonly seen in both groups, while smoking, drinking, hypertension, number of teeth, stimulated salivary flow salt intake and years of education were also shown to be associated with taste sensitivity. We found gender and cognitive status to be major factors affecting taste sensitivity in geriatric individuals.

Dietary Intake Is Associated with Occlusal Force Rather Than Number of Teeth in 80-y-Old Japanese

There has been a growing interest in the association between the number of teeth and dietary intake in older populations. However, people around the age of 80 y have frequently lost most of their teeth, and dental prostheses replacing the missing teeth play an important role in masticatory function. Therefore, masticatory function cannot be evaluated by the number of teeth alone. The occlusal force of the complete dental arches is an index of masticatory function, reflecting not only the number of teeth, but the effect of removable dentures. The purpose of this cross-sectional study was to determine the relative importance of the number of teeth and occlusal force in association with dietary intake in 80-y-old Japanese people. This study included 760 community-dwelling Japanese people aged 79 y to 81 y. The authors measured bilateral maximal occlusal force in the intercuspal position using pressure-sensitive sheets. Removable denture wearers kept their dentures in place during the measurements. Energy-adjusted food groups and nutrient intake during the preceding month were assessed by a brief self-administered diet history questionnaire. The authors assessed linear trends in food and nutrient intake in relation to the number of teeth and occlusal force after adjusting for gender and socioeconomic status (education level, financial status, family structure, resident area and BMI). P values of < 0.05 were considered to be statistically significant. The authors found that the number of teeth was not associated with the energy-adjusted intake of any food group examined. In contrast, a decline in occlusal force was significantly associated with a lower intake of vegetables, fish and shellfish, protein, polyunsaturated fatty acids, dietary fiber and most vitamins and minerals ( P for trend < 0.05). We conclude that food and nutrient intake was more closely associated with occlusal force than the number of teeth in community-dwelling Japanese people aged 79 y to 81 y. Knowledge Transfer Statement: This cross-sectional study of older Japanese people showed that, after controlling for considerable covariates, occlusal force rather than the number of teeth is positively associated with energy-adjusted intake of vegetables, fish and shellfish, protein, polyunsaturated fatty acids, dietary fiber and most of vitamins and minerals. This means that reduced occlusal force may unconsciously lead older people toward a habitual unhealthy dietary intake. Older people have frequently lost most of their teeth and require prosthetics to restore masticatory function. Bilateral occlusal force is therefore a better measure of masticatory function than the number of remaining teeth. Our findings suggest that prosthetic rehabilitation is a significant factor in the prevention and management of chronic diseases and frailty through better dietary intake in older populations.

Association of Occlusal Force with Cognition in Independent Older Japanese People

Recent longitudinal studies have shown the influence of multiple tooth loss on cognitive impairment, and earlier studies suggested that periodontal disease was related to cognitive decline. Tooth loss is associated with reduced masticatory function, which may affect stimulation of the central nervous system and dietary intake. Although some studies have reported a relationship between chewing ability and cognitive function, no studies have examined this area in terms of objective oral function. The aim of this study was to examine the association of occlusal force with cognitive decline in the preclinical stage among older people with higher-level functional capacity. This cross-sectional study for community-dwelling older people living in urban and rural areas in Japan examined 994 persons in the 70-y group (age range, 69–71 y) and 968 persons in the 80-y group (age range, 79–81 y). Retention of higher-level competence was defined according to the Tokyo Metropolitan Institute of Gerontology Index of Competence. Cognitive function was measured with the Japanese version of the Montreal Cognitive Assessment (MoCA-J). Oral status and function were assessed by the number of remaining teeth, periodontal pocket depth, and maximal occlusal force. Associations between the MoCA-J score and occlusal force were examined by bivariate and multivariate analysis. Approximately one-half of the participants retained higher-level functional capacity and were included in the analysis. Multiple regression analysis showed that occlusal force was significantly related to cognitive function after controlling for possible predictors including age, sex, socioeconomic status, medical condition, and handgrip strength. The number of remaining teeth and periodontal pocket depth were not significantly associated with cognitive function. Among community-dwelling older people with retained competence, maximal occlusal force was positively associated with their cognitive function. These results suggest that oral function might be a predictor for preclinical cognitive decline. Knowledge Transfer Statement: Multiple regression analysis showed that occlusal force was significantly related to cognition after controlling for possible predictors including handgrip strength as an indicator of general muscle strength, suggesting the independence of oral function. The number of remaining teeth did not have this association. The majority of older people have lost teeth and have received prosthodontic treatment, and their occlusal force is determined not only by the number of remaining teeth but also by prosthetic rehabilitation. These results can be used by clinicians focusing on prevention of tooth loss among the entire population, as well as to encourage partially edentulous and fully edentulous patients to restore their oral function with prostheses in order to eliminate a possible risk factor for cognitive impairment.

Crossover trial for comparing the biofunctional prosthetic system with conventional procedures

Context: The rapid provision of high.quality complete dentures is an unmet clinical need in some populations. Novel procedures may simplify this service but require validation against existing methods. Aims: The aim of this trial was to evaluate the clinical acceptability of complete dentures fabricated using the biofunctional prosthetic system. (BPS) when compared with conventional methods. Materials and Methods: This study was designed as a crossover trial. The patients wore either a complete denture, which was made using the biofunctional prosthetic system biofunctional prosthetic system complete denture (BPSCD) or a complete denture made with conventional procedures conventional complete denture (CCD) for 3. months before switching to the other dentures. The patients were asked to report their satisfaction levels in an abbreviated version of the Oral Health.Related Quality of Life questionnaire, specifically designed for edentulous patients. (Oral Health Impact Profile for edentulous subjects. [OHIP-EDENT]). Furthermore, the number of adjustments required for each technique to deliver pain.free fitting was noted. Finally, the patients were asked to state which denture gave them superior occlusal feel, comfort, esthetics, and retention and which denture they wished to keep for the long-term. Results: Although the satisfaction score and the OHIP.-EDENT scores showed no significant differences, the majority of patients preferred the BPSCD over the CCD in terms of occlusal feel, comfort, esthetics, and retention. Nine out of 10 patients chose to keep the BPSCD rather than the CCD, with one patient choosing the CCD for purely esthetic reasons. Conclusions: Within the limitation of this study, the BPS produced high.quality complete dentures with satisfactory results and was just as efficient as conventional procedures.

Occlusal force is correlated with cognitive function directly as well as indirectly via food intake in community-dwelling older Japanese: From the SONIC study

Background Growing evidence suggests that oral health may be an important factor associated with cognitive function in aged populations. However, many previous studies on this topic used insensitive oral indicators or did not include certain essential covariates. Thus, we examined the association between occlusal force and cognitive function in a large sample of older adults, controlling for dietary intake, vascular risk factors, inflammatory biomarkers, depression, and genetic factors. Methods In this cross-sectional study of older community-dwelling Japanese adults, we examined data collected from 994 persons aged 70 years and 968 persons aged 80 years. Cognitive function was measured using the Japanese version of the Montreal Cognitive Assessment (MoCA-J). Oral status and function were evaluated according to the number of remaining teeth, periodontal pocket depth, and maximal occlusal force. Associations between MoCA-J scores and occlusal force were investigated via bivariate and multivariate analyses. Results Education level, financial status, depression score, and intake of green and yellow vegetables, as well as number of teeth and occlusal force, were significantly correlated with MoCA-J scores in both age groups. Among individuals aged 80 years, CRP and periodontal status were weakly but significantly associated with MoCA-J score. After controlling for all significant variables via bivariate analyses, the correlation between maximal occlusal force and cognitive function persisted. A path analysis confirmed the hypothesis that cognitive function is associated with occlusal force directly as well as indirectly via food intake. Conclusions After controlling for possible factors, maximal occlusal force was positively associated with cognitive function directly as well as indirectly through dietary intake.

Influence of lack of posterior occlusal support on cognitive decline among 80-year-old Japanese people in a 3-year prospective study: Influence of occlusion on cognition

Previous studies have reported significant associations between tooth loss or periodontal status and cognitive function; however, animal experimental studies have shown that occlusion might be a more important factor in cognitive decline. The purpose of the present study was to investigate the influence of a lack of posterior occlusal support by residual teeth on the decline of cognitive function over a 3‐year period among 80‐year‐old Japanese people.