Kaori Enoki

Association of masticatory performance with age, gender, number of teeth, occlusal force and salivary flow in Japanese older adults: Is ageing a risk factor for masticatory dysfunction?

OBJECTIVE In general, ageing is a risk factor for sensory and motor deterioration, with the rate of decline varying amongst individuals. Concerning masticatory function, missing teeth along with oral disease seem to accelerate the dysfunction. Here, we aimed to confirm whether masticatory dysfunction by ageing is inevitable. This study investigated the effect of age, gender, number of natural teeth, occlusal force and salivary flow on the masticatory performance in a large sample of elderly adults. DESIGN The study sample consisted of 1288 independently living people aged 60-84 years. Masticatory performance was determined by the comminuted particles of test food. Bilateral maximal occlusal force in the intercuspal position was measured with pressure sensitive sheets. Stimulated whole saliva was collected. RESULTS Masticatory performance was significantly correlated to age, number of residual teeth, occlusal force and stimulated salivary flow rate by Pearsons correlation test. The multiple linear regression analysis showed that, with other variables controlled, masticatory performance was significantly associated with the number of residual teeth (β=0.456, P<0.001), occlusal force (β=0.244, P<0.001) and stimulated salivary flow rate (β=0.069, P=0.003). Age was not related to masticatory performance (β=-0.007, P=0.753). CONCLUSIONS Declines in the number of residual teeth, occlusal force and salivary flow were associated with a reduction of masticatory performance in older adults. If tooth loss is not considered as an attribute of physiological ageing, then ageing by itself may not be a risk factor for masticatory dysfunction.

Masticatory performance in older subjects with varying degrees of tooth loss.

OBJECTIVES The purpose of this study was to establish the factors influencing the masticatory performance of older subjects with varying degrees of tooth loss and associated numbers of posterior occlusal contacts. METHODS The subjects consisted of 1274 independently living people aged 60 years and over. Individuals with partially or fully edentulous arches without a denture replacement or those having any symptoms related to an oral problem were excluded from the study participants. Masticatory performance, maximal occlusal force and stimulated whole saliva were measured. Subjects were grouped into three categories by posterior occlusal contact, according to the Eichner Index. Group A had contacts in four support zones; group B had one to three zones of contact or contact in the anterior region only; and group C had no support zones at all, although a few teeth could still remain. RESULTS The masticatory performance in groups B and C was found to be 81% and 50% of that of group A, respectively. The multiple linear regression analysis showed that in all the groups, occlusal force was significantly associated with masticatory performance. In groups A and B, the number of residual teeth was significantly associated with masticatory performance, whereas in group C, it had no significant relationship with masticatory performance. Salivary flow rate had a significant correlation with masticatory performance only in group C. CONCLUSIONS Declines in occlusal contact, occlusal force and salivary flow appear to be associated with reduction of masticatory performance in older adults. However, the crucial factors for masticatory performance varied, depending on the phase of occlusal collapse.

Comparison of GOHAI and OHIP‐14 measures in relation to objective values of oral function in elderly Japanese

OBJECTIVES The aims of this study were to assess the correlations between the Geriatric Oral Health Assessment Index (GOHAI) and the Oral Health Impact Profile-14 (OHIP-14) and to examine which survey is more sensitive to objectively measured oral function in the Japanese elderly. METHODS The subjects were 290 community-dwelling, cognitively healthy, and independently living people over the age of 60 years (mean: 66.3 years). Measures included the GOHAI and OHIP-14 questionnaires, as well as self-rating of general and oral health, dry mouth, number of residual teeth, and objective values of occlusal force, masticatory performance, and salivary flow rate. Bivariate and linear regression analyses were used to identify which of these variables predicted GOHAI and OHIP-14 scores. RESULTS Spearmans correlation coefficient between the GOHAI and OHIP-14 scores was 0.728 (P < 0.001), although the OHIP-14 showed a greater number of 0 scores, suggesting a greater floor effect. At the bivariate level, self-rating of general and oral health, dry mouth, number of residual teeth, occlusal force, and masticatory performance were associated with GOHAI and OHIP-14 scores. Multiple linear regression analyses showed that after controlling for the other significant variables, both the occlusal force (standardized regression coefficient [β] = -0.164, P = 0.004) and masticatory performance (β = -0.125, P = 0.019) had significant associations with the GOHAI score, whereas this association was not found with the OHIP score. CONCLUSIONS Although the GOHAI and OHIP-14 had a strong correlation, the GOHAI was more sensitive to the objective values of oral functions among independently living elderly persons in Japan.

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.

Influence of xerostomia on oral health–related quality of life in the elderly: a 5-year longitudinal study

OBJECTIVE Xerostomia and tooth loss are major oral health problems in the elderly. The aim of this longitudinal study was to characterize the influence of xerostomia on oral health-related quality of life (OHRQoL) among elderly Japanese people. STUDY DESIGN A total of 99 community-dwelling, independently living individuals aged 60 years and older were interviewed and underwent dental examination at baseline and at a 5-year follow-up. The Oral Health Impact Profile-14 and the Xerostomia Inventory were used to assess OHRQoL and xerostomia severity, respectively. RESULTS Participants whose xerostomia worsened over the 5-year period had a significantly poorer follow-up OHRQoL. Linear regression models showed that tooth loss and worsening xerostomia were significant predictors of poorer follow-up OHRQoL. CONCLUSIONS Tooth loss and worsening xerostomia result in poorer OHRQoL among older Japanese people.

Determinants of change in oral health-related quality of life over 7 years among older Japanese

Because there are more elderly people than ever before and because they are living for longer periods of time, it is essential to understand the determinants of healthy ageing. This study examined changes in oral health-related quality of life (OHRQoL) among Japanese elderly over a 7-year period. A sample of independently living individuals (aged 60+ years) underwent a questionnaire and dental examination at baseline and 7 years afterwards. The Geriatric Oral Health Assessment Index (GOHAI) was used to assess the impact of oral conditions. Occlusal force and salivary flow were also assessed. Of the 411 participants assessed at baseline, 130 (31·6%) accepted to participate after 7 years. There were no significant differences between those lost to follow-up and those assessed at 7 years, except that a higher proportion of the latter rated their baseline general health as good. Among the latter, the overall mean GOHAI score did not change significantly (11·8 at baseline and 11·1 at follow-up; P = 0·16). However, after controlling for age, gender and baseline GOHAI score, participants who had lost teeth or experienced a decline in occlusal force after 7 years had higher follow-up GOHAI scores (indicating poorer OHRQoL). Unfavourable changes in clinical oral status over time are reflected in poorer self-rated oral health.

Investigation of oral opportunistic pathogens in independent living elderly Japanese

OBJECTIVE Pneumonia is reported to be associated with high morbidity in elderly and compromised individuals, with poor oral health demonstrated to be a significant risk factor for pneumonia. Several opportunistic pathogens, such as Streptococcus pneumoniae, Klebsiella pneumoniae, Escherichia coli and Staphylococcus aureus, have been detected in patients with pneumonia. We investigated the prevalence of opportunistic pathogens in the oral cavity of healthy independent living Japanese elderly subjects and analysed factors related to harbouring those pathogens. MATERIALS AND METHODS We studied 265 subjects, each of whom received a dental examination, during which specimens were collected with a tongue swab and examined for the presence of 10 oral opportunistic pathogens using single or multiple selective media. Furthermore, the presence of occult blood in saliva was examined using test paper strips. RESULTS Oral opportunistic pathogens were detected in 13.6% of the subjects. Those positive for occult blood in saliva had a significantly higher rate of harbouring the pathogens (p < 0.05). In addition, age was a significant factor for the presence of pathogenic microbes in the oral cavity (p = 0.033). CONCLUSION Positive findings of occult blood in saliva and older age are suggested to be significant factors for harbouring opportunistic pathogens in the oral cavity.

Incidence and association of root fractures after prosthetic treatment.

PURPOSE Common reasons for tooth extractions include periodontal disease, dental caries and root fracture. The purpose of this study was to investigate the association of tooth loss after prosthetic treatment, particularly incidences due to root fracture, which occur frequently and are difficult to prevent. METHODS Data were collected from consecutively selected medical records of patients taken over 3 years after their initial visit to Osaka University Dental Hospital. Collected data included (1) age and gender, (2) number of teeth at the initial visit and number of extracted teeth, (3) reasons for extraction, (4) restored with or without a post and (5) abutment of removable partial dentures (RPDs). A Chi-squared test was applied among the reasons for extraction, whether the tooth was restored with a post or not and clasped or not. A logistic regression analysis was used to determine the associations of root fracture with the patient data. RESULTS This study included 101 patients (296 extracted teeth). The reasons for extraction included periodontal disease (64.6%), caries (25.3%) and root fracture (10.1%). The percentage of root fracture was significantly higher for female than male, for restored teeth with posts than without posts and for abutment of RPDs than for non-abutment teeth. Logistic regressions showed that root fractures were significantly associated with gender and abutments. CONCLUSION The most frequently stated reasons for tooth extraction after prosthetic treatment were periodontal disease and dental caries, followed by root fracture. Root fractures were significantly associated with gender and abutment teeth of RPDs.

Influence of hypertension on pH of saliva in older adults.

BACKGROUND Hypertension and/or antihypertensive medication reportedly induce dry mouth; however, an immediate relationship between salivary flow and hypertension has not been elucidated. OBJECTIVES The purpose of the present study was to examine the association of hypertension and antihypertensive medication with salivary flow rate and pH in older adults. SUBJECTS Subjects were independently living volunteers aged 60-78 years taking no medication (n = 138) or only antihypertensive medication (n = 27). Unstimulated saliva and stimulated saliva by the mastication method were collected, and salivary pH was measured. Hypertension was defined as systolic blood pressure of ≥ 140 mmHg and/or diastolic blood pressure of ≥ 90 mmHg. RESULTS There was no significant correlation between either hypertension or intake of antihypertensive medication and unstimulated or stimulated salivary flow rate. However, multiple regression analysis showed that hypertension was significantly associated with pH of unstimulated saliva after controlling for other variables (β = -0.270, P = 0.003). CONCLUSION Hypertension regardless of antihypertensive medication was related to a lower pH of unstimulated saliva. Blood pressure might be a required consideration for maintenance of oral health in older individuals.

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.