Oral health status in relation to cognitive function among older Japanese.

Epidemiologic data examining the relationship between oral health status and cognitive status are sparse, especially in Asian populations. This study aimed to assess whether periodontal disease and tooth loss were related to cognitive impairment among older Japanese. Study participants were 291 Japanese (101 men and 190 women, average age: 80.9 years), classified into three groups based on a clinical examination of oral health status: no periodontal disease, periodontal disease, and edentulous. Periodontal disease was defined using criteria recommended in the consensus report of the European Workshop in Periodontology with a modification. Cognitive impairment was defined using the results of the Mini-mental State Examination (MMSE) and Hasegawa Dementia Scale-Revised (HDS-R) scores. Multivariable logistic regression analyses assessed the relationship of the three-category oral health status variable (reference category = no periodontal disease) with low MMSE score (≤23) and low HDS-R score (≤20). Age, gender, years of education, body mass index, smoking status, drinking behavior, and history of cardiovascular disease were tested as potential confounders in the multivariable models. Periodontal disease and edentulous were significantly associated with greater odds of low cognitive performance after controlling for potential confounders. The multivariable adjusted odds ratios (ORs) (95% confidence intervals [CIs]) for low MMSE score associated with periodontal disease and edentulous were 2.21 (1.01-4.84) and 2.28 (1.06-4.90), respectively. The multivariable adjusted ORs (95% CIs) for low HDS-R score associated with periodontal disease and edentulous were 4.85 (1.29-18.15) and 3.86 (1.05-14.20), respectively. Poor oral health status was significantly associated with cognitive impairment among community-dwelling older Japanese. Additional well-controlled longitudinal studies are needed to elucidate whether there may be a possible cause-and-effect relationship between oral health status and cognitive function.

Evaluation of chewing ability and its relationship with activities of daily living, depression, cognitive status and food intake in the community-dwelling elderly.

AIM: The aim of this study was to assess chewing ability using color-changeable chewing gum and to show the association between chewing ability and geriatric functions, as well as dietary status in the community-dwelling elderly. METHODS: The study population consisted of 269 community-dwelling elderly aged ≥ 75 living in Tosa, Japan. Assessment of chewing ability was carried out by a dentist using color-changeable chewing gum. Activities of daily living (ADL), depression and subjective quality of life (QOL) were assessed by questionnaire. Cognitive status was assessed by; Mini-Mental State Examination (MMSE), Hasegawa Dementia Scale-Revised (HDS-R) and Frontal Assessment Battery (FAB) during the check-up. Food diversity was assessed using the 11-item Food Diversity Score Kyoto (FDSK-11). RESULTS: Number of teeth was significantly related to chewing ability (P<0.001). The participants with low chewing ability had significantly lower ADL scores in the items of self-maintenance (P=0.029) and intellectual activity (P=0.021). There was a significant association between low chewing ability and depression (P<0.001). Lower cognitive functions were significantly related to low chewing ability; MMSE (P=0.022), HDSR (P=0.017) and FAB (P=0.002). The participants with low chewing ability had lower food variety (P<0.001), and less frequent intake of beans, vegetables, seaweed and nuts, than the participants with high chewing ability. CONCLUSION: Low chewing ability evaluated by color-changeable gum was associated with lower ADL, lower cognitive functioning, depression and food insufficiency in the community-dwelling elderly. More attention should be paid to assessing chewing ability of elderly persons in community settings.

The development of nano-modified Ti(C,N) cermets.

The unique combination of mechanical properties such as excellent wear resistance and good chemical stability at elevated temperature helps titanium carbonitride based (Ti (C, N)-based) cermets to play an important roles in metal cutting operations. Nowadays, cermets cutting tools are widely used for semi-finishing and finishing works on steel and cast iron. However, their brittleness is still an unavoidable limitation for their utilization. With the development of nano-technology, nano-modified cermets have received more attention due to the high toughening enhancements. In this review, the development of nano-modified Ti(C,N) cermets is discussed including the fabrication, microstructure, mechanical properties, cutting performance and the practical applications in different fields. Many patents having important effect on the development of cermets were noticed, too.