Yohei Hama

Background: The number of children with poor oral function, known as developmental insufficiency of oral function (DIOF), has increased, negatively affecting children's growth and development. Research on the overall prevalence of DIOF in children is limited. Objective: We aimed to investigate the prevalence of DIOF in community‐dwelling children aged 5–7 years and examine its relationship with eating habits that may affect oral function. Methods: We analysed data from children who participated in the Survey on All‐Generation Masticatory Strength and Eating Habits. Chi‐square tests were used to examine the relationship between the incidence of DIOF and participant characteristics. Logistic regression was used to explore the relationship between eating habits and participant characteristics, namely oral function and DIOF incidence. Results: Ninety‐two children (aged 5.6 ± 0.1, 47 males) were included in the final analysis, 23% of whom had DIOF. Children who preferred hard foods were less likely to have DIOF (adjusted odds ratio = 0.636, 95% confidence interval 0.405–0.998, p = 0.049). The frequency of hard food intake had no influence on DIOF incidence. Conclusion: Approximately one in four children who participated in the study had DIOF. A preference for hard food was associated with a reduced risk of DIOF, indicating the importance of dietary texture in oral function development. Given the cross‐sectional design of this study, further research is needed to explore the development of oral function through oral and dietary education.

With the global rise in the aging population, the relationship between oral function and risk of long-term care is attracting attention. One method for subjective assessment of masticatory function is the use of a food acceptance questionnaire. Although it is hypothesized that objective oral functions such as tongue pressure and swallowing function are associated with subjective masticatory performance, this relationship has yet to be investigated. The aim of this study is to elucidate the association between overall oral function and subjective masticatory performance using a food questionnaire. Patients aged ≥ 65 years were recruited from an outpatient dental clinic at Tokyo Medical and Dental University. Subjective masticatory performance was assessed using the food acceptance score as described in a previous study. Seven oral function parameters defined by the Japanese Society of Gerodontology, were measured. Age, sex, number of functional teeth, geriatric depression, cognitive function, and oral health-related quality of life were assessed. Variables for which normality was rejected were transformed into tertile values. Multiple regression analysis was conducted with the food acceptance score as the objective variable, and each oral function parameter and other items as explanatory variables. This study included 201 participants (87 males and 114 females). Multiple regression analysis revealed that the number of functional teeth, geriatric depression, oral health-related quality of life, objective masticatory performance, tongue pressure, and swallowing function were substantially associated with the food acceptance scores. This study demonstrated that subjective masticatory performance was independently associated with tongue pressure, objective masticatory performance, swallowing function, number of functional teeth, geriatric depression, and oral health-related quality of life.

Background: Differences in the effects of cream‐type denture adhesives and home liners remain unclear.Objective: This cross‐sectional study aimed to clarify the differences in the oral‐hygiene status and masticatory performance between participants using cream‐type denture adhesives and those using home liners.Methods: Masticatory performance with and without cream‐type denture adhesives and home liners was evaluated using colour‐changeable chewing gum. Oral hygiene was assessed using the tongue coating index (TCI). Propensity‐score matching was performed using oral moisture, presence of palatal or mandibular protuberances, type of residual ridge, denture type (complete or partial denture), and denture retention as background factors. Wilcoxon signed‐rank test was used to examine the differences in masticatory performance with and without cream‐type denture adhesives and home liners and differences in masticatory performance and TCI between the cream‐type denture adhesive and home‐liner groups.Results: This study included 38 and 40 cream‐type adhesive and home‐liner users, respectively, and 17 pairs were obtained after propensity‐score matching. The Wilcoxon signed‐rank tests showed that masticatory performance was significantly different with and without the use of home liners, and higher values were obtained with the use of home‐liners. However, the cream‐type denture adhesive and home‐liner groups showed no significant differences in terms of the change in masticatory performance with the use of them. Furthermore, Wilcoxon signed‐rank tests showed that TCI values were significantly high in the cream‐type adhesive group.Conclusion: The findings in this study suggest that home liners improve masticatory performance and that participants regularly using cream‐type denture adhesives have poorer oral hygiene.

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.

The type of denture adhesive, cream or home-liner, chosen by regular denture adhesive users and oral conditions contributing to this selection require elucidation. The factors associated with denture adhesive selection were investigated through a face-to-face survey on oral and denture conditions. Age, sex, oral moisture, masticatory performance, retention and stability of the removable denture, ridge shape, mucosal thickness, and duration of denture use were examined in cream and home-liner-type denture adhesive users who did not regularly visit a dentist. Univariate analysis and multivariate analyses were performed. There were 38 and 40 cream-type and home-liner-type adhesive users, respectively. The type of denture adhesive was significantly associated with the oral moisture value, retention, ridge shape, mucosal thickness, and duration of denture use in univariate analyses. The residual ridge conditions with large factor loadings for ridge shape and mucosal thickness and duration of denture use were significantly related to the denture adhesive selection in multivariate logistic analysis. The residual ridge conditions and duration of denture use were significant factors in the selection of cream- and home-liner-type denture adhesives. These results can provide appropriate guidance based on the adhesives patients without dental supervision are more likely to choose.

症例の概要：66歳男性，見た目が悪いこと，食事がしづらいことを主訴に来院した．残存歯の傾斜・挺出により，著しい咬合平面不正を呈していた．咬合高径の挙上，抜歯，便宜抜髄の後に下顎前歯に根面板，上顎クラウン・ブリッジ，上顎部分床義歯，下顎全部床義歯を製作し，咬合平面の是正を行った． 考察：咬合平面是正のために，咬合高径挙上を伴う顎間関係の修正が必要であった．まず治療用義歯を用いて許容される咬合高径を判断してから最終補綴を行うことで，良好な結果を得ることができた． 結論：咬合平面是正をしたことで，咀嚼機能の回復および患者の高い満足を得ることができた．術後３年以上，問題なく経過している．

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.

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.

Background: An increase in the number of elderly edentulous patients likely leads to a greater demand for dentures and denture adhesives. As denture adhesives have both positive and negative features, dentists need to know the types of denture adhesive users to be able to provide instruction to denture wearers on how to use denture adhesives effectively. This study aims to examine the utilization of denture adhesives and associated factors. Methods: Seven closed-ended questionnaires were developed for a web-based survey. After that, Fisher’s exact tests were performed to determine the difference in the denture adhesive usage rate by gender, type of denture, last dental visit, and smoking status. A multivariate-adjusted logistic regression analysis was performed with denture adhesive use or non-use as the dependent variable and the other items as independent variables. Next, Fisher’s exact tests and a multivariate-adjusted logistic regression analysis were performed with the type of denture adhesives as the dependent variable in the same way. Statistical analyses were performed for all denture wearers, complete denture wearers, and partial denture wearers. The level of statistical significance was set at p = 0.05. Results: A total of 1470 denture wearers in Japan participated in this study. Of these, 318 used denture adhesives, while 212 (66.7%) used cream; 74 (23.3%) used home liner; 25 (7.9%) used powder; four (1.3%) used sheets; and three (0.9%) used several types. The Fisher’s exact tests revealed that the ratios of using denture adhesives were significantly higher for complete denture wearers (p < 0.001), last dental visit over 1 year (p = 0.005), and smokers (p = 0.005). For partial denture wearers, the ratio was significantly higher in smokers (p = 0.262). The multivariate adjusted logistic regression revealed that denture adhesive use or non-use were significantly associated with the type of denture and smoking status in all denture wearers, and just smoking status in partial denture wearers. There were no significant results about the type of denture adhesive selection. Conclusions: From all denture wearers, complete denture wearers and smokers are more likely to use denture adhesives. In addition, smokers significantly use denture adhesives if they are partial denture wearers.