Reliability and validity of a questionnaire for self-assessment of complete dentures.

BACKGROUND: Demand for complete denture treatment is expected to rise over several decades. However, to date, no questionnaire on complete dentures, as evaluated by edentulous patients, has been shown to be reliable and valid. This study sought to assess the reliability and validity of Patient's Denture Assessment (PDA), which provides a multidimensional evaluation of dentures among edentulous patients. METHODS: Patients, who had new complete dentures fabricated at the University Hospital of Dentistry, Tokyo Medical and Dental University through 2009 to 2010, were enrolled. The reliability of the PDA was determined by examining internal consistency and test-retest reliability. Internal consistency for all of the question items and the six subscales was measured using Cronbach's α and average inter-item correlation coefficients among 93 participants. For 33 of these participants, test-retest reliability was determined at a 2 month-interval using the interclass correlation coefficients (ICCs) and 95% confidence interval for the summary scores and the six subscale scores. The PDA was validated in 93 participants by examining the difference in the summary score and the six subscale scores of the PDA before and after replacement with new dentures by the paired t-test. Ability to detect change was also tested in 93 patients using effect size. RESULTS: The Cronbach's α for the PDA ranged from 0.56 to 0.93. The average inter-item correlation coefficients ranged from 0.28 to 0.83. ICCs for the PDA ranged from 0.37 to 0.83. The paired t-test showed a significant difference between the summary score and the six subscale scores before and after replacement with new dentures (p < 0.05) and the effect size was 0.97. CONCLUSIONS: The PDA demonstrated good reliability by assessing internal consistency and test-retest reliability. In addition, the PDA demonstrated good validity by assessing discriminant validity. Thus, the PDA could help dentists obtain a detailed understanding of the patients' perceptions in using their dentures.

Reliability and validity of a Japanese version of the Oral Health Impact Profile for edentulous subjects.

OBJECTIVE: To evaluate the reliability and validity of the Japanese version of the Oral Health Impact Profile for edentulous (OHIP-EDENT-J) patients. BACKGROUND: Oral Health Impact Profile for edentulous is an appropriate instrument for assessing the Quality of life (QOL) in edentulous patients. However, the reliability and validity of the Japanese version had not been evaluated. METHODS: The study was conducted on 116 edentulous patients (Group A, requiring new dentures, n = 61; Group B, already having dentures, n = 55). Cronbach's alpha (α) was used to measure internal consistency of the summary scores for OHIP-EDENT-J and various subscales in Groups A and B. The interclass correlation coefficient (ICC) and 95% confidence interval of the summary scores for OHIP-EDENT-J and subscales were calculated. The summary scores for OHIP-EDENT-J in Groups A and B were compared with evaluate content validity. The Spearman's correlation coefficient between the summary scores for OHIP-EDENT-J and the satisfaction with dentures (100 mm VAS) was calculated for Groups A and B to evaluate concurrent validity. RESULTS: The reliability of the summary scores for OHIP-EDENT-J was good (α = 0.93). The ICC of the summary scores for OHIP-EDENT-J was 0.85. Summary scores for OHIP-EDENT-J were significantly different (p = 0.027) between Group A and Group B, with Group A having the higher value. The Spearman's correlation coefficient for the degree of satisfaction with dentures and the summary scores for OHIP-EDENT-J, calculated for Groups A and B (n = 107), was -0.609. CONCLUSION: The OHIP-EDENT-J, a questionnaire on oral health-related QOL comprising 19 items, showed good reliability and validity for edentulous patients.

Influence of palatal coverage on oral function - oral stereognostic ability and masticatory efficiency.

PURPOSE: Oral sensorimotor function performs an important role in mastication. This study investigated the influence of wearing experimental palatal plates on masticatory efficiency and oral stereognostic ability (OSA), and the relationship between these two functions. METHODS: Fifteen young adults with healthy dentitions (mean age, 26.4 years) participated in this study. Masticatory efficiency was determined using a sieving method and OSA test was conducted by 12 shaped forms. These tests were performed in random order under three different conditions: control (without experimental plate), Plate-A (a horseshoe-shaped and 10mm in width from the gingival cuff) and Plate-B (the entire palate was covered). The thickness of experimental plate was 1.5mm. The statistical significance level was set at P<0.05. RESULTS: Masticatory efficiency was significantly reduced with Plate-B, but not with Plate-A, compared with control. OSA scores were not significantly influenced by the presence of either plate. A significant positive correlation existed between masticatory efficiency and OSA score in control and with Plate-A, but not with Plate-B. CONCLUSION: We suggest that wearing Plate-A had no influence on masticatory efficiency and did not disturb oral sensorimotor control of the masticatory mechanism, while wearing Plate-B reduced masticatory efficiency and might have an effect on the relationship between OSA and mastication in young dentate adults.

Evaluation of denture retention and ease of removal from oral mucosa on a new gel-type denture adhesive.

PURPOSE: The purpose of this study was to evaluate the effect of a new gel-type denture adhesive on denture retention and ease of removal from the oral mucosa after use. METHODS: Eleven complete denture wearing patients (3 males and 8 females; age range, 58-84 years; mean age, 73.7 years) with compromised maxillary denture-bearing tissues were included in the study. Denture retention and ease of removal were evaluated for a new gel-type denture adhesive. The results were compared with those obtained with and without a cream-type denture adhesive. Retention was evaluated by measuring unilateral bite force until these dentures were dislodged on the balancing side. Ease of removal was evaluated by scoring the remaining area of colored denture adhesives on the oral mucosa. Denture retention and ease of removal were also subjectively evaluated using questionnaires. RESULTS: A significant improvement in objective denture retention was observed when either the creamtype or gel-type denture adhesive was used (p<0.05). A significant difference in objective ease of removal was observed between cream-type and gel-type denture adhesive when subjects had rinsed their mouth once (p<0.05). Subjective assessment showed no significant differences in either retention or ease of removal between gel-type and cream-type denture adhesives (p=0.26, 0.24). CONCLUSIONS: Objectively, denture retention was higher with the cream-type than with the gel-type denture adhesive. Removal of the gel-type denture adhesive from the oral mucosa was easier than that of the creamtype. Subjectively, there were no differences in either retention or ease of removal.

Palatal coverage disturbance in masticatory function.

Oral sensorimotor function is essential for mastication. We hypothesized that palatal coverage would disturb mastication and sensorimotor function. Masticatory efficiency, which was expressed by the declination rate of particle size, and oral stereognosis ability (OSA) were measured for 20 dentate subjects. Both measurements were first performed without an experimental palatal plate. These measurements were then repeated with the plate on the day of the plate insertion, then again on the 3rd and 7th day. After 2 months, another series of measurements for the OSA test were performed without the plate with the same time-course. Masticatory efficiency significantly decreased with the plate. OSA score, which continuously increased during the experimental period, showed no difference between with and without the plate. Positive correlation between masticatory efficiency and the OSA score was found only without the plate. It was suggested that coordination between mastication and the sensorimotor function was disturbed by palatal coverage.