Yuko Kurushima

Significance of occlusal force for dietary fibre and vitamin intakes in independently living 70-year-old Japanese: from SONIC Study

OBJECTIVES The number of teeth has frequently been used as an indicator of oral health in investigations of food intake; however, this measure does not represent the efficacy of the masticatory performance. Masticatory performance may be more important for food selection and avoidance than number of remaining teeth. The aim of this study was to investigate the association of occlusal force with habitual dietary intakes in independently living older Japanese. METHODS The study population was 757 community-dwelling people aged 69-71 years old. Bilateral maximal occlusal force in the intercuspal position was measured with pressure-sensitive sheets. Removable denture wearers kept their dentures in place during the measurements. Dietary habits during the preceding month were assessed using a brief-type self-administered diet history questionnaire that measures consumption frequencies of selected food commonly consumed and calculates energy-adjusted dietary intakes. Linear trends of food and nutrient intakes with decreasing occlusal force were tested after adjusting for gender and socioeconomic factors. RESULTS After adjusting for socioeconomic status and the number of remaining teeth, decline of occlusal force was significantly associated with lower intakes of vegetables, vitamins A, C, B6, folate, and dietary fibre (P for trend<0.05). In contrast, number of teeth was significantly associated only with calcium and zinc, controlling for occlusal force. CONCLUSIONS It is concluded that occlusal force was significantly associated with intakes of vitamins and dietary fibre rather than number of remaining teeth in independently living older Japanese.

Association of personality traits with oral health-related quality of life independently of objective oral health status: A study of community-dwelling elderly Japanese

OBJECTIVES Oral health-related quality of life (OHRQoL) is being increasingly used in epidemiologic studies of dentistry. However, patient-reported OHRQoL does not always coincide with clinical measures. Previous studies have shown a relationship between OHRQoL and personality, but did not concomitantly investigate oral function. We aimed to examine the association among personality traits, oral function, and OHRQoL using a large sample of community-dwelling Japanese elderly. METHODS The participants (n = 938; age, 69-71 years) were drawn from a complete enumeration of an urban area and a rural area of both the Tokyo metropolitan area and Hyogo Prefecture. The self-perceived impact of OHRQoL was measured using the Geriatric Oral Health Assessment Index (GOHAI). The oral status and socioeconomic characteristics were recorded in each participant, and personality traits (neuroticism, extraversion, openness to experience, agreeableness, and conscientiousness) were assessed with the NEO-five-factor inventory. Multiple linear regression analysis was performed to examine the relationships between OHRQoL and other factors, with p < 0.05 considered to be statistically significant. RESULTS Neuroticism was negatively associated with the GOHAI score in bivariate analyses (Spearman rank-order correlation coefficient (rs )= -0.20), whereas extraversion was positively associated (rs = 0.17). In the regression analyses, neuroticism (standardized partial regression coefficient (β) = -0.179) and extraversion (β=0.094) were significantly associated with the GOHAI scores independently of the number of teeth, maximal occlusal force, and financial status. CONCLUSIONS Personality traits are associated with OHRQoL independently of objective measures of oral health status in community-dwelling elderly Japanese. CLINICAL SIGNIFICANCE This study showed personality traits are associated with OHRQoL independently of dental status and oral function in old Japanese people. As elderly patients undergo increasingly complex dental treatments, there is a need to evaluate patient personality traits prior to dental treatment and predict patient expectations and responses to planned treatment. This is advantageous in determining the most appropriate therapy.

Replacement of a mandibular implant-fixed prosthesis with an implant-supported overdenture to improve maintenance and care

PATIENTS A 69-year-old woman presented to the Osaka University Dental Hospital. She had two chief complaints, (a) food accumulation under the lower teeth and (b) poor maxillary denture retention while eating. On clinical examination the patient presented with a maxillary complete denture and fixed mandibular implant prosthesis. For preventing food accumulation under the fixed implant prosthesis and to keep the maxillary denture stable by providing posterior occlusal contact for bilaterally balanced occlusion, the use of a mandibular implant-supported overdenture with self-adjusting magnetic attachments provided a prosthetic solution for this patient. After provided the new dentures, the patient was pleased and was comfortable with the aesthetic, stability and retention of the dentures. There were no discernable clinical or radiographic changes after 1 year of use. DISCUSSION To prevent food accumulation beneath the fixed implant prosthesis and maintain the stability of the maxillary denture by providing posterior occlusal contact for bilaterally balanced occlusion, a mandibular implant-retained overdenture with magnetic attachments was used to provide a prosthetic solution for this patient. CONCLUSION In this clinical case, an implant-fixed prosthesis in the edentulous mandibular region was replaced into an implant-supported overdenture with considerations for (a) preventing the food accumulation beneath the lower prosthesis, (b) achieving the proper occlusion in the posterior part for maxillary denture stability and (c) ease of maintenance and care for the prostheses.

Influence of genetic and environmental factors on oral diseases and function in aged twins

This study was conducted to quantify the genetic and environmental contributions to oral disease and function in twins. Participants were middle-aged and old twins, 116 monozygotic and 16 dizygotic pairs whose mean age was 66·1 ± 10·3 (SD) years. Number of teeth, percentage of decayed, filled and missing teeth and periodontal status were recorded as indicators of oral disease. The widths of upper and lower dental arch served as indicators of morphological figures. Furthermore, stimulated salivary flow rate, occlusal force and masticatory performance were measured as indicators of oral function. Univariate genetic analysis with monozygotic and dizygotic twin pairs was conducted to detect the fittest structural equation model of each outcome. Both number of teeth and periodontal status fitted the model composed of common environmental factor and unique environmental factor. Decayed, filled and missing teeth, morphological figures and measurements of oral function fitted the model composed of additive genetic factor and unique environmental factor. The model fitting of each measurement suggested that periodontal disease was mainly affected by environmental factors, while morphological figures and oral functions were influenced by both genetic and environmental factors.

Does case severity make a difference to clinical improvement following complete denture treatment

PURPOSE The aim of this study was to investigate the effect of case severity on clinical outcomes when fabricating new complete dentures. MATERIALS AND METHODS Participants were separated into severe and moderate groups using the index of case difficulty for edentulous patients developed by the Japan Prosthodontic Society. Before and after treatment, self-assessed masticatory ability and oral health-related quality of life (OHRQoL) were examined, and the authors compared them according to case severity using the Mann-Whitney U test. To compare findings before and after treatment, the authors used the Wilcoxon signed rank test. RESULTS In the severe group, both scores were significantly improved after treatment (P < .01). However, in the moderate group, there was no significant difference in self-assessed masticatory ability as measured by the food acceptance score before and after treatment (P = .11). Before treatment, OHRQoL as measured by the Oral Health Impact Profile score was significantly higher in the severe group than in the moderate group (P < .01). However, after treatment, there was no significant difference between the two groups (P = .92). CONCLUSIONS The authors concluded that case severity makes a difference in the edentulous patients OHRQoL and self-assessed masticatory ability during complete denture treatment. Evaluating case severity with the index before treatment is a useful tool for patients and clinicians to predict clinical outcomes.

Crossover trial for comparing the biofunctional prosthetic system with conventional procedures

Context: The rapid provision of high.quality complete dentures is an unmet clinical need in some populations. Novel procedures may simplify this service but require validation against existing methods. Aims: The aim of this trial was to evaluate the clinical acceptability of complete dentures fabricated using the biofunctional prosthetic system. (BPS) when compared with conventional methods. Materials and Methods: This study was designed as a crossover trial. The patients wore either a complete denture, which was made using the biofunctional prosthetic system biofunctional prosthetic system complete denture (BPSCD) or a complete denture made with conventional procedures conventional complete denture (CCD) for 3. months before switching to the other dentures. The patients were asked to report their satisfaction levels in an abbreviated version of the Oral Health.Related Quality of Life questionnaire, specifically designed for edentulous patients. (Oral Health Impact Profile for edentulous subjects. [OHIP-EDENT]). Furthermore, the number of adjustments required for each technique to deliver pain.free fitting was noted. Finally, the patients were asked to state which denture gave them superior occlusal feel, comfort, esthetics, and retention and which denture they wished to keep for the long-term. Results: Although the satisfaction score and the OHIP.-EDENT scores showed no significant differences, the majority of patients preferred the BPSCD over the CCD in terms of occlusal feel, comfort, esthetics, and retention. Nine out of 10 patients chose to keep the BPSCD rather than the CCD, with one patient choosing the CCD for purely esthetic reasons. Conclusions: Within the limitation of this study, the BPS produced high.quality complete dentures with satisfactory results and was just as efficient as conventional procedures.

Occlusal force is correlated with cognitive function directly as well as indirectly via food intake in community-dwelling older Japanese: From the SONIC study

Background Growing evidence suggests that oral health may be an important factor associated with cognitive function in aged populations. However, many previous studies on this topic used insensitive oral indicators or did not include certain essential covariates. Thus, we examined the association between occlusal force and cognitive function in a large sample of older adults, controlling for dietary intake, vascular risk factors, inflammatory biomarkers, depression, and genetic factors. Methods In this cross-sectional study of older community-dwelling Japanese adults, we examined data collected from 994 persons aged 70 years and 968 persons aged 80 years. Cognitive function was measured using the Japanese version of the Montreal Cognitive Assessment (MoCA-J). Oral status and function were evaluated according to the number of remaining teeth, periodontal pocket depth, and maximal occlusal force. Associations between MoCA-J scores and occlusal force were investigated via bivariate and multivariate analyses. Results Education level, financial status, depression score, and intake of green and yellow vegetables, as well as number of teeth and occlusal force, were significantly correlated with MoCA-J scores in both age groups. Among individuals aged 80 years, CRP and periodontal status were weakly but significantly associated with MoCA-J score. After controlling for all significant variables via bivariate analyses, the correlation between maximal occlusal force and cognitive function persisted. A path analysis confirmed the hypothesis that cognitive function is associated with occlusal force directly as well as indirectly via food intake. Conclusions After controlling for possible factors, maximal occlusal force was positively associated with cognitive function directly as well as indirectly through dietary intake.

Examination of the Relationship between Oral Health and Arterial Sclerosis without Genetic Confounding through the Study of Older Japanese Twins.

Objective Although researchers have recently demonstrated a relationship between oral health and arterial sclerosis, the genetic contribution to this relationship has been ignored even though genetic factors are expected to have some effect on various diseases. The aim of this study was to evaluate oral health as a significant risk factor related to arterial sclerosis after eliminating genetic confounding through study of older Japanese twins. Subjects and Methods Medical and dental surveys were conducted individually for 106 Japanese twin pairs over the age of 50 years. Maximal carotid intima-media thickness (IMT-Cmax) was measured as a surrogate marker of arterial sclerosis. IMT-Cmax > 1.0 mm was diagnosed as arterial sclerosis. All of the twins were examined for the number of remaining teeth, masticatory performance, and periodontal status. We evaluated each measurement related with IMT-Cmax and arterial sclerosis using generalized estimating equations analysis adjusted for potential risk factors. For non-smoking monozygotic twins, a regression analysis using a “between within” model was conducted to evaluate the relationship between IMT-Cmax and the number of teeth as the environmental factor controlling genetic and familial confounding. Results We examined 91 monozygotic and 15 dizygotic twin pairs (males: 42, females: 64) with a mean (± standard deviation) age of 67.4 ± 10.0 years. Out of all of the oral health-related measurements collected, only the number of teeth was significantly related to arterial sclerosis (odds ratio: 0.72, 95% confidence interval: 0.52-0.99 per five teeth). Regression analysis showed a significant association between the IMT-Cmax and the number of teeth as an environmental factor (p = 0.037). Conclusions Analysis of monozygotic twins older than 50 years of age showed that having fewer teeth could be a significant environmental factor related to arterial sclerosis, even after controlling for genetic and familial confounding.

Overeruption of teeth opposing removable partial dentures: a preliminary study.

One of the purposes of prosthodontic treatment is to prevent overeruption of opposing teeth, but there is currently minimal literature describing the efficacy of removable partial dentures (RPDs) in performing this function. This study investigated overeruption following RPD treatment. The study participants were 33 patients treated with RPDs, and overeruption was evaluated by comparing the surface computeraided design data of dental casts made at two different time points-before and after RPD treatment. Overeruption was observed in 38.1% of teeth opposed by the RPD, which was much less than the proportion of teeth that overerupted when not opposed by the RPD.