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.

Factors related to masticatory performance in junior and senior high school students and young adults: A cross-sectional study.

PURPOSE: Maintaining good masticatory function from a young age promotes lifelong health, yet limited studies have explored masticatory performance in young individuals. We investigated the relationship of sex, age, and individual oral functions with masticatory performance among junior and senior high school students and young adults. METHODS: This cross-sectional study included students aged 12-13, 14-15, and 16-17 years (groups S1, S2, and S3, respectively) and young adults aged 20-40 years (group YA). We assessed oral functions, the number of functional teeth, and anthropometric measurements. Masticatory performance was evaluated using color-changeable chewing gum. We analyzed sex-related differences in each group and age-related differences in each sex. Multiple linear regression analysis was performed using masticatory performance as the dependent variable to investigate related factors. RESULTS: Among the 522 children and 100 young adults, males exhibited significantly higher masticatory performance than females in groups S1, S3, and YA. Among males, groups S2, S3, and YA exhibited significantly higher masticatory performance than group S1. Among females, group S2 exhibited higher masticatory performance than groups S1 and S3. Male sex, the maximum occlusal force and tongue pressure, and the number of functional teeth were significantly correlated with masticatory performance. CONCLUSIONS: Masticatory function development differed by sex, with males exhibiting higher masticatory performance than females. We identified that male sex, the maximum occlusal force and tongue pressure, and the number of functional teeth were significantly associated with masticatory performance. Our findings provide a basis for masticatory performance assessment in different age groups.

Gender differences in the relationship between personality, cognitive function and regular dental visits in Japanese community-dwelling older adults.

OBJECTIVES: Studies have examined the association between personality and health behaviour, but research focusing exclusively on regular dental visits has yet to be conducted. This study examined the association between personality traits and regular dental visits among Japanese community-dwelling older adults. METHODS: The participants in this cross-sectional study included 1,057 community-dwelling older adults aged 65-74 years from Ranzan and Yoshimi towns; data were collected from October to November 2015 and October to November 2016, respectively. Interviews were conducted to obtain sociodemographic, income, occupation and medical data. The Tokyo Metropolitan Institute of Gerontology Index of Competence was used to assess higher-level competence; general intelligence was also evaluated. The 'Big Five' personality traits-openness to experience, consciousness, neuroticism, extraversion and agreeableness-were also examined. A multivariable logistic regression analysis was performed to examine the relationship between regular dental visits and personality traits. RESULTS: Among men, the number of natural teeth, current employment status and conscientiousness were associated with dental care utilization. Among women, the number of natural teeth, current annual income, the intellectual activity domain of the Tokyo Metropolitan Institute of Gerontology Index of Competence and openness were significant. CONCLUSIONS: The factors associated with regular dental visits differed by gender. Overall, work was associated with men's visits, whereas intellectual activity and economic factors were relevant to women. Factors such as personality traits should be considered when addressing barriers to oral health. Understanding personality traits will help practitioners more effectively encourage older adults to make dental visits.

Age and sex differences in oral functions from junior high school to young adulthood: A cross-sectional study.

BACKGROUND: As oral function requires maintenance throughout life, it needs to be understood across age groups; however, few studies have investigated this in young individuals. OBJECTIVES: To clarify age and sex differences in maximum occlusal force, maximum tongue pressure and tongue-lip motor function; and the relationship among these oral functions in junior high school students and young adults. METHODS: This cross-sectional study investigated oral functions in students aged 12-13 years, 14-15 years old and 16-17 years old (S1, S2 and S3), and young adults aged 20-40 years (YA). We analysed age group differences in each sex and sex differences in each age group. Multiple linear regression analysis was performed for each sex using the maximum occlusal force as the dependent variable to investigate the associations among different oral functions. RESULTS: In 522 children and 100 young adults, there were significant increases in oral functions with age in males and a significant decrease in maximum tongue pressure between S2 and S3 in females. Maximum occlusal force and tongue pressure were higher in males than in females in S3 and YA; tongue-lip motor function was higher in females than in males in S1. In multiple linear regression analysis, tongue-lip motor function and age group were significant factors in both sexes and in males, respectively. CONCLUSION: Maximum occlusal force, maximum tongue pressure and tongue-lip motor function increased with increasing age groups in males. Our findings provide a basis for assessing oral function across age groups.

Factors related to removable denture use in independent older people: A cross-sectional study.

BACKGROUND: Denture use for recovery of major tooth loss can reduce the need for care, and thus, it is important for dentists to identify the types of patients who use removable dentures. OBJECTIVE: To identify factors associated with removable denture use in independent older Japanese people. METHODS: This cross-sectional study investigated the oral condition; demographics; lifestyle; dental visit behaviour; and higher-level functional capacity, as assessed using the Tokyo Metropolitan Institute of Gerontology index of competence (TMIG index), of independent older people aged 65-74 years. Participants were divided into four groups based on sex and condition of the posterior occluding pairs (POPs). Multivariate-adjusted logistic regression analyses were performed for each group, with denture use or non-use as the dependent variable and the other items as independent variables. RESULTS: Denture use or non-use was significantly associated with only dental consultation behaviour (regular dental visits and time since the last dental visit) in all groups. Subsequent analyses excluding dental consultation behaviour demonstrated that denture use or non-use was significantly associated with educational background in female participants with decreased POPs, with the type of household in male participants with lost POPs and with the TMIG index (social role) in female participants with lost POPs. CONCLUSIONS: Denture use was associated with dental consultation behaviour. We revealed factors related to denture use or non-use in females with decreased POPs and both males and females with lost POPs.

Association between chewing-stimulated salivary flow under the effects of atropine and mixing ability assessed using a color-changeable chewing gum.

PURPOSE: To assess the time course of chewing-stimulated salivary flow after oral atropine administration, and determine the association between chewing-stimulated salivary flow and mixing ability using color-changeable chewing gum in dentate adults. METHODS: Ten healthy dentate adults were administered 1mg oral atropine to induce mouth dryness. The subjects' chewing-stimulated salivary flow was assessed using the Saxon test. They were then asked to rinse their mouth with tap water for 15s, and to chew on color-changeable chewing gum for 60s at a constant rate of 60 cycles per min. This procedure was performed before, and at 10-min intervals for up to 120min after the atropine administration. The experiment was repeated after 1 week. Steel's test was used to compare the chewing-stimulated salivary flow rates at each time point after atropine administration with the baseline value. The effect of the stimulated salivary flow rates on the degree of color change was analyzed using linear mixed effects models, with the stimulated salivary flow rates as fixed factors and subjects as the random factor. RESULTS: Chewing-stimulated salivary flow showed a significant decrease from 50 to 120min after oral atropine administration (P<0.05) and the amount of chewing-stimulated salivary flow had a significant effect on the color change of the color-changeable chewing gum (P<0.001). CONCLUSIONS: We observed a decrease in stimulated salivary flow after orally administering 1mg atropine, and a positive association between mixing ability using color-changeable chewing gum and chewing-stimulated salivary flow in dentate subjects.

[The effect of oral care on natural immune function in the dependent elderly].

While oral care is known to play an important role in the prevention of aspiration pneumonia, its influence on immune function is unclear. In this study, we performed oral care on ten dependent elderly individuals and examined its influence on NK cell activity. The study duration was 12 weeks. During the first six weeks, the subjects cleaned their mouths as usual (control period). In the last six weeks, a dental hygienist performed oral care and denture cleaning three times a week (intervention period). The outcome measure was the quantity of oral bacteria and the detection rate of the microbe in connection with an opportunistic infection and NK cell activity before and after the intervention. Samples were collected at three time points: the beginning of the study, after the control period and before the intervention period (i. e., after six weeks), and after the intervention period (i. e., after 12 weeks). There was no significant difference in the number of oral bacteria between the control period and the intervention period. In contrast, while NK cell activity did not change during the control period, activity increased during the intervention period (p = 0.03). This finding suggests that rather than decreasing the number of oral bacteria, oral care increases NK cell activity.