Accuracy of newly developed color determination application for masticatory performance: Evaluating color-changeable chewing gum.

PURPOSE: Color-changeable chewing gums are used to evaluate masticatory performance, as measured by a colorimeter or visually based on a color scale. Although anyone can use a color scale, the evaluation accuracy depends on the evaluator. We develop an application that can determine the degree of color change in chewing gum using smartphone images, making color evaluation accurate and easy to measure. METHODS: For the application, 60 chewed gum samples were prepared. Two shots were captured using two smartphone models. To create the application algorithm, a formula was developed to approximately map the color value from the smartphone images to the true value using a colorimeter. A basic validation was performed on 60 new samples covering a range of colors, followed by a field validation on 100 healthy dentate participants aged 20-39 years. RESULTS: The intraclass correlation coefficient for two repeated shots had a high value ≥ 0.97 in the basic and field validations, confirming reliability. No significant differences were observed in the paired t-test and Wilcoxon signed-rank test, and a significant and strong correlation (correlation coefficient ≥ 0.92) was observed between the evaluation values using the colorimeter and the basic and field validations. Bland-Altman plots further confirmed the validity of the application. CONCLUSIONS: A software application was developed to enable easy, quick, and accurate determination of the masticatory performance of a chewing gum from images taken using a smartphone with highly reliable and validated results.

Factors Associated with Selection of Denture Adhesive Type: A Cross-Sectional Survey.

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.

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.

Relationship Between Oral Health-Related Quality of Life and Usage Period of Complete Dentures.

PURPOSE: To investigate the relationship between oral health-related quality of life (OHRQoL) and usage period of complete dentures. MATERIALS AND METHODS: Data were obtained from 432 edentulous patients who required complete dentures as part of an investigation registered in the University Hospital Medical Information Network (UMIN) Center (UMINCTR clinical trial, unique trial number: 000028711). Mandibular ridge form, denture quality, and usage period of the dentures were recorded and incorporated into a multiple linear regression analysis. RESULTS: Multiple linear regression analysis in the 267 participants who completed the study demonstrated significant effects on OHRQoL of mandibular ridge form, mandibular denture stability and retention, accuracy of jaw relation recording, and usage period of dentures. CONCLUSION: A significant relationship between the usage period of dentures and OHRQoL in complete denture wearers was noted when the effects of mandibular ridge form and denture quality were controlled for.

Structural equation modeling of the impact of mandibular ridge form and denture quality on oral health-related quality of life in complete denture wearers.

PURPOSE: To examine the effect of mandibular ridge form and denture quality on oral health-related quality of life (OHRQoL) in complete denture wearers by using structural equation modeling (SEM) analysis of data before and after new complete denture insertion. METHODS: Four hundred thirty-two edentulous patients who visited the Dental Hospital of Tokyo Medical and Dental University for new complete dentures were recruited. An intervention study design was conducted, including complete denture fabrication with SEM analysis. Mandibular ridge form, mandibular denture stability, accuracy of jaw relation record, and the Oral Health Impact Profile for edentulous subjects (OHIP-EDENT-J) total score before and after new complete denture insertion were used in the hypothesized model. RESULTS: Two hundred and thirty-seven participants completed the research. SEM analysis demonstrated adequate model fit. Path coefficients of mandibular ridge form to OHIP-EDENT-J before and after insertion, and mandibular denture stability to OHIP-EDENT-J before insertion, were significant. CONCLUSIONS: This study demonstrated that mandibular denture stability and mandibular ridge form are important to ensure successful complete denture therapy.

A structural equation model to assess the influence of neuroticism on oral health-related quality of life in complete denture wearers.

OBJECTIVE: To investigate the influence of patient neuroticism on oral health-related quality of life (OHRQoL) in complete denture wearers. BACKGROUND: There are some indicators of complete denture prognosis. The relationship between personality traits, mainly neuroticism and OHRQoL in complete denture wearers remains unclear. MATERIALS AND METHODS: A total of 199 edentulous patients participated in this study. Neuroticism was investigated using the Japanese version of the modified short form of the Eysenck Personality Questionnaire (MS-EPQ). OHRQoL was measured according to the Japanese version of the Oral Health Impact Profile for edentulous subjects (OHIP-EDENT-J). Structural equation modelling was used to evaluate the relationship between neuroticism and subscales of the OHIP-EDENT-J. RESULTS: The High and Low neuroticism groups fit the same model for the 5 subscales of the OHIP-EDENT-J-functional limitation, pain, disability, discomfort and handicap-with different path coefficients. The path from functional limitation to handicap via pain, disability and discomfort was the same as previously reported. However, path coefficients for pain to disability differed significantly between the 2 neuroticism groups. The High neuroticism group had higher estimated path coefficients for Pain compared with those for other subscales than did the Low neuroticism group. This finding indicates that the participants who are high in neuroticism felt pain more strongly, and their disability increased. CONCLUSIONS: Neuroticism may influence OHRQoL in complete denture wearers because of patients' perception of pain.