A double blind randomized clinical trial comparing lingualized and fully bilateral balanced posterior occlusion for conventional complete dentures.

PURPOSE: A lingualized occlusion (LO) for complete dentures reduces lateral inferences and occlusal force contacts and direction; thus, LO is theorized to be more suitable for patients with compromised ridges than fully bilateral balanced articulation (FBBA). However, no studies have yet provided evidence to support LO in edentate patients with compromised alveolar ridges. The purpose of this study was to compare LO and FBBA in edentulous individuals with compromised ridges. METHODS: Sixty edentulous individuals were randomly allocated into groups and received dentures with either LO or FBBA. Following delivery, several denture-related satisfaction variables were measured using 100mm visual analogue scales; oral health-related quality of life (OHRQoL) was also assessed using the Oral Health Impact Profile (OHIP). Sub-group analyses of the effect of moderate and severe mandibular bone loss were also carried out. RESULTS: No significant differences were detected between LO and FBBA with the primary outcome. At 6 months, participants with severely atrophied mandibles and FBBA rated their satisfaction with retention of mandibular dentures significantly lower than those with LO (median LO: 86, FBBA: 58.5, p=0.03). They also had significantly lower OHRQoL for the domain of Pain (median LO: 4, FBBA: 5, p=0.02). General satisfaction and total OHIP scores significantly improved between baseline and 6 months only for the LO subjects with severely atrophied mandibles (satisfaction: p=0.003, OHIP total score: p=0.0007). CONCLUSIONS: The results indicate that the LO occlusal scheme with hard resin artificial teeth is more efficient for patients with severely resorbed mandibular ridges.

Influence of mandibular residual ridge resorption on objective masticatory measures of lingualized and fully bilateral balanced denture articulation.

PURPOSE: To assess the influence of mandibular residual ridge resorption (RRR) on objective masticatory measures of two occlusal schemes: lingualized occlusion (LO) and fully bilateral balanced articulation (FBBA). METHODS: The enrolled patients (n=22) were randomly allocated one set of complete dentures with either LO or FBBA. Maximum occlusal force, masticatory performance (by the MPI), and mandibular movements were measured at 3- and 6-month follow-ups. Mandibular RRR was assessed as the sum of the mandibular bone height at the midline, first premolar region, and least vertical height region, and from the mental foramen to the alveolar crest, measured on panoramic radiographs; the treatment groups were subclassified into severe or moderate RRR subgroups by the value of the sum of individual measurements. RESULTS: Significant differences were observed in the between-subgroup comparisons (Kruskal-Wallis test) of the MPI (3 months, p=0.01; 6 months, p=0.04) and linear deviation from intercuspal position (anterior-posterior: 6 months, p=0.01; inferior-superior: 3 months, p=0.008; 6 months, p=0.02). The patients with severe RRR in the FBBA group showed a significant decrease in the MPI and increase in linear inferior deviation from intercuspal position at 3 months (post hoc comparison) as well as a significant increase in the linear posterior and inferior deviation from intercuspal position at 6 months. CONCLUSIONS: LO is the preferable occlusal scheme for patients with severe RRR.

The use of existing denture-satisfaction ratings for a diagnostic test to indicate prognosis with newly delivered complete dentures.

PURPOSE: The study investigated the relation between subjective satisfaction ratings of existing dentures and outcomes of newly delivered dentures, and the ability of the diagnostic test, using existing ratings, to indicate prognosis with newly delivered dentures. METHODS: Consecutive 165 edentulous patients were recruited from November 2001 to August 2006 at a university-affiliated hospital. Dentures were fabricated with an acrylic base with full-balanced occlusion using hard resin artificial teeth by multiple prosthodontists. At the baseline and 3-month after delivery, patients rate their overall, maxillary, and mandibular satisfaction for existing and replaced dentures on a 100-mm visual analogue scale (VAS). The association between baseline ratings and newly delivered dentures was analyzed by regression analysis. The test's performance was measured by constructing a two-by-two table; patients with the following cutoff values on the VAS (overall:

Investigation on how renewal of complete dentures impact on dietary and nutrient adequacy in edentulous patients.

PURPOSE: The aim of this study is to investigate changes of diet and nutrient adequacy between complete denture wearers with their existing dentures and those with new dentures. METHODS: After obtained their written informed consent 30 patients who visited Nihon University School of Dentistry at Matsudo Affiliated Hospital from March 2004 to November 2005 were asked to record their 3 consecutive day's meals and to take a picture of them. Furthermore, foods which they can eat with their dentures were examined the questionnaire developed by Hirai. Referring to the obtained records and pictures, one dietitian interviewed to confirm the exact intakes of meals. In addition, the masticatory ability was calculated using the questionnaire. The nutrient adequacy and masticatory score determined at the time of the first and second survey were examined by repeated-measures ANOVA. A p-value less than 0.05 was considered statistically significant. RESULT: The total intake of energy and nutrients was almost over 100% in both the groups. However, no statistically significant difference was obtained. The masticatory score with the existing and new denture were 66.1+/-18.5 and 58.3+/-19.9, respectively. The score increased significantly in the new denture group when compared with that of the existing denture group. CONCLUSION: The self-evaluation of the masticatory function improved after the switch from the old to new dentures.

[Comparative analysis of learning effect for students who experienced both lecture-based learning and problem-based learning in a complete denture course].

PURPOSE: The purpose of this study was to analyze the difference in educational effect on students who experienced both lecture-based learning (LBL) and problem-based learning (PBL) in a complete denture course. The analysis focused on differences between the two methods concerning self study, ability to understand clinical inference, and appraisal of class contents and tutors. METHODS: In the complete denture preclinical course, the class of 2003 received LBL in 3rd grade and PBL in 4th grade. PBL was planned to present five cases in five consecutive classes. Group discussion was carried out for each case, and a summary was required to be produced two times as a group, two times as an individual report and one time by group presentation. A questionnaire regarding the educational effect of LBL and PBL and assessment of tutors was administered. Factor analysis was carried out to classify the questionnaire items and each item was analyzed between LBL and PBL (Paired-t test). RESULTS: Factor analysis revealed that the questionnaire items could be classified into four components. Comparing lecture type and PBL: "study attitude" (4 out of 7 items), "clinical inference ability" (all items), "class contents" (5 out of 7 items) and "tutor appraisal" (2 out of 5 items) showed significant assessment with PBL. Eighteen of 27 items (66.6%) indicated the significant usefulness of PBL. CONCLUSION: PBL improves the educational effect of self study and clinical inference ability, in comparison with LBL. However, since students are passive about taking the same system class repeatedly, a strategy to improve their attitude needs to be considered.