Factors related to subjective evaluation of difficulty in chewing among community-dwelling older adults.

AIM: Awareness of difficulty chewing may limit the diversity of food intake in older adults. However, few studies have clarified which factors are related to subjective difficulty in chewing. The aim was to identify factors related to subjective difficulty in chewing in 70- and 80-year-old Japanese older adults. METHODS: A total of 1680 participants (792 men, 888 women) were surveyed. Difficulty in chewing was assessed with questionnaires regarding food intake, such as rice, apples, beef, and hard rice crackers. The participants were classified into two groups, the "with difficulty" group (participants who answered "cannot eat," "can eat with difficulty," and "can eat if small") and the "without difficulty" group (participants who answered "can eat without problems"), according to their answers to questionnaires for each food. A logistic regression analysis with subjective difficulty in chewing as the dependent variable was performed for each food. RESULTS: Subjective difficulty in chewing was associated with age, occlusal force, and depression for rice; age, number of remaining teeth, occlusal force, and depression for apples; number of remaining teeth, occlusal force, and depression for beef; and number of remaining teeth and occlusal force for hard rice crackers. CONCLUSIONS: Age, number of remaining teeth, and occlusal force, as well as depression, might be related to subjective evaluation of difficulty chewing in community-dwelling Japanese older adults. Geriatr Gerontol Int 2024; 24: 327-333.

Risk factors of cognitive impairment: Impact of decline in oral function.

Cognitive impairment and subsequent dementia are the major causes of disability and need for nursing care among older people in worldwide. The purpose is to review well-known risk factors for cognitive impairment and dementia, focusing on the relationship between decline in oral function and current prevention strategies. Various non-modifiable and modifiable risk factors are related to cognitive impairment. Effects of oral function to cognitive impairment is not yet well recognized in the medical community, although masticatory function, occlusal force, and number of teeth have been reported to be related to cognitive function. Furthermore, occlusal force rather than number of teeth was significantly related to the early stages of cognitive impairment, and that a decline in occlusal force seemed to lead to cognitive impairment directly and indirectly through dietary intake. This relationship was significant only for occlusal force, which may be associated with the early stages of cognitive decline. Nutritional change caused by reduced masticatory function is suggested as a possible explanation. Therefore, rehabilitation or maintenance of oral function should be sought to prevent cognitive impairment.

The relationship between changes in occlusal support and masticatory performance using 6-year longitudinal data from the SONIC study.

OBJECTIVES: Reduced occlusal support is thought to be related to a decline in masticatory performance. However, previous research in this field was based on cross-sectional studies. In this study, we conducted a 6-year longitudinal observation of older adults living in the community and examined the associations of changes in occlusal support with masticatory performance. METHODS: Of the 864 participants aged 72-74 years in the SONIC study, 488 who were followed up (median follow-up period 5.92 years) and had no missing data were included in this study. Participants were divided into three groups according to the number of occlusal support zones in the posterior area: Complete occlusion (four zones), Reduced occlusion (one to three zones), and Collapsed occlusion (no occlusal support zone). Longitudinal analysis of the relationship between occlusal support and masticatory performance was undertaken with linear mixed-effects models. RESULTS: Sex, occlusal force, number of unreplaced missing teeth, aging, and occlusal support change were significantly related to masticatory performance. Furthermore, the interaction term between change in occlusal support and aging was a significant explanatory variable for the decline in masticatory performance. The interaction was strongest in the group that changed from Complete or Reduced occlusion to Collapsed occlusion. This result indicates that the loss of occlusal support is a major factor contributing to declining masticatory performance. CONCLUSIONS: The decline of occlusal support was greatly associated with the deterioration of masticatory performance. Our results suggest that older adults need to prevent the collapse of posterior occlusal support to maintain their masticatory performance. CLINICAL SIGNIFICANCE: Occlusal support is important for preserving masticatory performance in older adults. Preventing the loss of molars and retaining occlusal support may contribute to maintaining food intake diversity and nutritional status, thereby improving quality of life. Dental professionals need to carefully examine dental status to assess the risk of occlusal collapse.

Relationship between the number of teeth, occlusal force, occlusal contact area, and dietary hardness in older Japanese adults: The SONIC study.

PURPOSE: Individuals with impaired masticatory function tend to prefer soft foods, which results in decreased masticatory muscle activity. This study examined the association between the oral condition (number of teeth, occlusal force, and occlusal contact area) and dietary hardness using a daily dietary questionnaire. METHODS: This cross-sectional study evaluated 1841 participants aged 69-71 and 79-81 years. Registered dentists examined the number of teeth, occlusal force, and occlusal contact area. Dietary hardness was defined as the estimated masticatory muscle activity required for a habitual diet. Habitual diet during the preceding month was assessed using a brief self-administered diet history questionnaire. Confounding factors, such as age, sex, socioeconomic status, smoking habits, history of chronic diseases (hypertension, hyperlipidemia, and diabetes), and cognitive function were also evaluated. Multivariate linear regression analyses were performed to assess the association between dietary hardness and each oral condition. RESULTS: Occlusal force (standardized regression coefficients [ß]=0.08, P < 0.01) and occlusal contact area (ß=0.06, P < 0.01) were significantly associated with dietary hardness after adjusting for the confounding factors. Number of teeth was not significantly associated with dietary hardness. In addition, the associations between dietary hardness, sex, and a history of diabetes were stronger than those between dietary hardness and oral factors. CONCLUSIONS: Occlusal force and contact area were significantly associated with dietary hardness as estimated from the masticatory muscle activity using a daily diet questionnaire.

Relationship between occlusal force and psychological frailty in Japanese community-dwelling older adults: The Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians study.

BACKGROUND: Frailty increases the risk of negative health-related events, such as falls, disability, hospitalizations, and death. Although the association between oral health and physical frailty is well established, the relationship between oral health and psychological frailty has not yet been investigated. Therefore, we conducted a cross-sectional study to examine the association between maximal occlusal force and psychological frailty in Japanese community-dwelling older adults. METHODS: Psychological frailty was defined as a World Health Organization-5 scale (WHO-5) score of <13, cognitive and functional status was defined as a Japanese version of the Montreal Cognitive Assessment (MoCA-J) score of <23, and psychological robustness was defined as a WHO-5 score of ≥13 and a MoCA-J score of ≥23. We used a cross-sectional study design to measure maximal occlusal force in 1810 participants, and examined the following factors relevant to psychological frailty: educational level, financial status, living situation, history of chronic diseases, handgrip strength, and instrumental activities of daily living. We used propensity score matching to match the psychological frailty and psychological robustness groups according to demographic and confounding factors. This process, resulted in 344 participants, of whom 172 were in the psychological frailty group and 172 were in the psychological robustness group. In the matched cohort, differences between groups with and without psychological frailty were compared using generalized estimating equations for maximal occlusal force after adjusting for the number of teeth. RESULTS: After controlling for potential confounding factors of frailty, the psychological frailty group showed lower maximal occlusal force compared with the psychological robustness group (unstandardized regression coefficients = -72.7, 95% confidence interval: -126.3 to -19.1). CONCLUSIONS: Maximal occlusal force was associated with a reduced prevalence of psychological frailty among Japanese community-dwelling older adults participating in our study.

Predictive factors for tooth loss in older adults vary according to occlusal support: A 6-year longitudinal survey from the SONIC study.

OBJECTIVES: The aim of this cohort study among community-dwelling older adults aged over 70 years was to investigate the influence of occlusal support on tooth loss, and to determine predictive factors for tooth loss for each occlusal support category using multilevel analyses. METHODS: Participants were 812 older adults who completed the baseline survey and the follow-up survey 6 years later. The Eichner index was used to evaluate occlusal support status. A generalized estimating equation (GEE) logistic regression analysis was used to examine the influence of occlusal support status on tooth loss while adjusting for various factors at individual and tooth levels. Similar analyses were separately performed in each Eichner class to determine predictive factors for tooth loss. RESULTS: The GEE showed that a decline in occlusal support increased the risk of tooth loss (Eichner A: reference category, Eichner B: odds ratio (OR) = 1.96, p < 0.001, Eichner C: OR = 3.04, p < 0.001). Stratified analysis showed that deeper periodontal pockets and abutment teeth for fixed partial dentures were significantly associated with tooth loss, regardless of occlusal support. In Eichner A, the presence of an opposing tooth was advantageous in protecting the tooth, and a missing adjacent tooth was not significantly associated with tooth loss. An opposing tooth was associated with the risk of tooth loss in Eichner B, and a missing adjacent tooth was significantly associated with tooth loss in Eichner B and C. CONCLUSIONS: A decline in occlusal support accelerated tooth loss. Predictive factors for tooth loss varied depending on occlusal support status. CLINICAL SIGNIFICANCE: Occlusal support is an important factor in preventing tooth loss. Dentition conditions such as missing adjacent teeth and the presence of opposing teeth increase the risk of tooth loss in participants with poor occlusal support. Dental personnel need to carefully examine dentition conditions to assess the risk of occlusal collapse.

Decline of oral functions in old-old adults and their relationship with age and sex: The SONIC study.

BACKGROUND: Many physical functions decline with aging, but it is not known whether oral functions vary according to sex or decline with aging, as it occurs with physical functions. The present study aimed to examine the association of sex, age, and elapsed years with occlusal force and tongue pressure using a generalized linear mixed-effect model (GLMM) over a 3-year period among old-old Japanese adults. METHODS: Participants were community-dwelling older adults who participated in a survey (June 2014-March 2017) and a follow-up survey (July 2017-December 2019) after 3 years (n = 951: 70-year group, n = 466; 80-year group, n = 391; 90-year group, n = 94). Dental examinations including the number of teeth, occlusal force, and tongue pressure were conducted, and a GLMM was used to estimate the association of sex, age, and elapsed years with occlusal force and tongue pressure, adjusting for the number of teeth. RESULTS: The GLMM showed that occlusal force was significantly associated with sex (reference; male, non-standardized coefficient: B = -66.9 [female], p < 0.001), age (reference; 70-year group, B = -81.7 [80-year group], p < 0.001, B = -87.2 [90-year group], p < 0.001), and the number of teeth (B = 13.8, p < 0.001), but did not significantly decrease with elapsed years. Tongue pressure was significantly associated with sex (reference; male, B = -0.94 [female], p = 0.034) and age (reference; 70-year group, B = -1.78 [80-year group], p < 0.001, B = -5.47 [90-year group], p < 0.001). Tongue pressure decreased significantly with elapsed years (B = -0.82, p < 0.001). CONCLUSIONS: These findings suggest that tongue pressure significantly decreased over time, but occlusal force did not. Tongue-related muscles may be more susceptible to aging than masticatory muscles.

Oral Functions Are Associated with Muscle Strength and Physical Performance in Old-Old Japanese.

Grip strength and walking speed are considered to be important indicators of physical frailty. However, no study has contemporaneously examined any association of multiple oral functions with grip strength and walking speed. The purpose of this study was to examine which oral functions are associated with muscle strength (grip strength), physical performance (walking speed) or both. The study participants were 511 community-dwelling people (254 men and 257 women) aged 77-81 years old. Six oral functions-oral wetness, occlusal force, tongue-lip motor function, tongue pressure, masticatory performance and swallowing function-were measured. Grip strength and walking speed were also measured. A partial correlation analysis, adjusted for gender, showed that occlusal force, tongue-lip motor function, masticatory performance and swallowing function were significantly associated with both grip strength and walking speed. In addition, tongue pressure was significantly associated with grip strength. A general linear model showed that tongue pressure and occlusal force were significantly associated with grip strength. Swallowing function and tongue-lip motor function were significantly associated with walking speed. It is suggested that there are different oral function measures for muscle strength and physical performance, and these oral function measures could be a useful proxy for physical frailty.

Periodontal inflamed surface area is associated with hs-CRP in septuagenarian Japanese adults in cross-sectional findings from the SONIC study.

Periodontal disease is a chronic inflammatory condition that affects various peripheral organs. The periodontal inflamed surface area (PISA) quantifies periodontitis severity and the spread of inflammatory wounds. This study aimed to investigate the association between PISA and high-sensitivity C-reactive protein (hs-CRP), a systemic inflammation marker. This study included 250 community-dwelling septuagenarians (69-71 years). We collected information on their medical (e.g., diabetes and dyslipidemia) and dental examinations (e.g., measurement of the probing pocket depth). Generalized linear model analysis was used to explore the association between PISA and hs-CRP levels. There was a significant difference in hs-CRP levels between groups with PISA ≥ 500 and < 500 (p = 0.017). Moreover, the generalized linear model analysis revealed a significant association between PISA and hs-CRP levels (risk ratio = 1.77; p = 0.033) even after adjusting other factors. Further, we found a correlation between PISA and hs-CRP (Spearman's rank correlation coefficient, rs = 0.181; p = 0.023). Our findings suggest that PISA is an effective index for estimating the effect of periodontitis on the whole body, enabling medical-dental cooperation.

Impact of occlusal force on decline in body mass index among older Japanese adults: Finding from the SONIC study.

OBJECTIVES: To determine any independent influence of occlusal force and of number of natural teeth on decline in body mass index (BMI) among older Japanese adults. DESIGN: Longitudinal study over a 3- to 6-year period. SETTING: Urban and rural area in Japan. PARTICIPANTS: Independently living Japanese adults aged 69-71 years and 79-81 years at baseline. This analysis excluded participants who were defined as underweight at baseline. MEASUREMENTS: Information was collected on age, gender, occlusal force, the number of teeth, BMI, socioeconomic factors, medical history, the number of daily prescription medications, cognitive function, depressive symptoms, hand grip strength, and physical function. Maximal occlusal force was measured with a pressure-sensitive sheet. Nutritional status was assessed using BMI, and participants with BMI <21.5 were defined as underweight. Then, they were divided into two groups: a "BMI declined" group who were defined as underweight at either 3- or 6-year follow-up survey, and a "BMI maintained" group who were not defined as underweight at both follow-up surveys. Logistic generalized estimating equation (GEE) models were used to assess the effect of occlusal force and the number of teeth at baseline on decline in BMI over 3 or 6 years, after adjusting for possible covariates associated with nutritional status. RESULTS: The final analysis included 704 participants. Eighty-six (12.2%) participants were classified into the BMI declined group. Logistic GEE models showed that the number of teeth was not significantly associated with decline in BMI. However, occlusal force was significantly associated with decline in BMI (odds ratio = 0.90, 95% confidence interval = 0.83-0.97) after adjusting for covariates. CONCLUSION: Participants with lower occlusal force were more likely to be in the BMI less than 21.5 kg/m2 . The findings suggest that to prevent decline in oral function is important to maintain nutritional status.

Association between oral health and sarcopenia: A literature review.

PURPOSE: Sarcopenia has recently been attracting attention as an early sign of the need for nursing care in older adults. Some studies have reported that oral health is related to sarcopenia and its diagnostic factors (hand grip strength, walking speed, and skeletal muscle mass). However, the relationship between oral health and sarcopenia remains poorly investigated and no review to date has compiled the available research on this relationship. The aim of this review was to summarize the current evidence describing the association between oral health and sarcopenia. STUDY SELECTION: The internet database PubMed was searched using various combinations of related and synonymous keywords for "oral" or "dental" or "oral health" or "oral function" and "sarcopenia" or "walking speed" or "hand grip strength" or "skeletal muscle mass." A total of 27 studies found to be eligible were critically evaluated and their key findings were summarized. RESULTS: Most of the studies were cross-sectional and conducted in Japan. A wide range of oral factors, including number of teeth, occlusal support, periodontal state, occlusal force, mastication, tongue pressure, and swallowing, were covered. The overall findings were that oral health indices could be significantly associated with sarcopenia and its diagnostic factors. CONCLUSIONS: Relationships may exist between aspects of oral health and sarcopenia or its diagnostic factors. However, reports showing associations between oral health and sarcopenia are scarce, and definitive conclusions could not be drawn. Further longitudinal studies are necessary to confirm these relationships.

Will implants with a fixed dental prosthesis in the molar region enhance the longevity of teeth adjacent to distal free-end edentulous spaces?

OBJECTIVES: Clinical evidence demonstrating the effectiveness of implants in preventing tooth loss is limited because of the many risk factors involved in tooth loss. This retrospective cohort study investigated whether an implant in the molar region of a distal free-end edentulous space affects the loss of the most distal tooth after 6 years, adjusting for other risk factors associated with tooth loss using propensity score matching analysis. MATERIAL AND METHODS: A total of 571 subjects and 1,085 teeth adjacent to a distal free-end edentulous space were evaluated. At baseline, the 1,085 teeth were divided into two groups according to the presence or absence of a molar implant with a fixed dental prosthesis in the distal free-end edentulous space. Propensity score matching analysis was used to reduce the effects of bias by matching teeth with and without implants according to similar background factors at baseline. The adjusted variables were age group, occlusal support status, Kennedy classification, tooth position, tooth type, restoration status, dental caries, periodontal pocket depth, and condition of the opposing tooth. RESULTS: A total of 56 teeth (28 associated with a molar implant; 28 with no implant) were enrolled according to propensity score matching. Fisher's exact test showed that a molar implant significantly protected the tooth adjacent to the distal free-end edentulous space (p = .01). CONCLUSIONS: Within the limitations of this retrospective cohort study, it was found that implants in free-end edentulous spaces may be beneficial in extending the longevity of adjacent teeth. Further research will be necessary to confirm this finding.

Association of periodontal disease with atherosclerosis in 70-year-old Japanese older adults.

Periodontal disease and arteriosclerotic disease are greatly affected by aging. In this study, the association of conventional risk factors and periodontal disease with atherosclerosis was longitudinally examined in Japanese older adults. Subjects in this study were 490 community-dwelling septuagenarians (69-71 years) randomly recruited from the Basic Resident Registry of urban or rural areas in Japan. At the baseline examination, all subjects underwent socioeconomic and medical interviews; medical examinations, including examinations for carotid atherosclerosis, hypertension, diabetes mellitus, and dyslipidemia; and conventional dental examinations, including a tooth count and measurement of probing pocket depth (PPD). After 3 years, 182 septuagenarians who had no atherosclerosis at the baseline examination were registered and received the same examination as at the baseline. In the re-examination conducted 3 years after the baseline survey, 131 (72.0%) of the 182 participants who had no atherosclerosis at the baseline examination were diagnosed with carotid atherosclerosis. Adjusting and analyzing the mutual relationships of the conventional risk factors for atherosclerosis by multiple logistic regression analysis for the 171 septuagenarians with a full set of data, the proportion of teeth with PPD ≥ 4 mm was independently related to the prevalence of atherosclerosis (odds ratio: 1.029, P < 0.022). This longitudinal study of Japanese older adults suggests that periodontal disease is associated with the onset/progression of atherosclerosis. Maintaining a healthy periodontal condition may be an important factor in preventing the development and progression of atherosclerosis.

Occlusal force predicted cognitive decline among 70- and 80-year-old Japanese: A 3-year prospective cohort study.

PURPOSE: Dementia is a growing health problem for countries with aging populations, but few effective dementia treatments are available. However, there is increasing interest in oral health as a modifiable risk factor in interventions to prevent cognitive decline. This study aimed to investigate the impact of oral health on the decline of cognitive function over 3 years among Japanese people aged 70 and 80 years. METHODS: Participants (n = 860) were community-dwelling older adults who participated in baseline and follow-up surveys (at baseline: 69-71 years n = 423; 79-81 years, n = 437). Registered dentists examined the number of teeth, number of functional teeth, number of periodontal teeth, and occlusal force. The Japanese version of the Montreal Cognitive Assessment was used to evaluate cognitive function. We also evaluated socioeconomic factors, medical history, drinking and smoking habits, physical performance, genetic factors, and C-reactive protein concentration in blood. A generalized estimating equation (GEE) was used to examine how oral health at baseline influenced cognitive decline over 3 years. RESULTS: The GEE showed that the number of teeth (non-standardized coefficient: B = 0.031, p = 0.022) and occlusal force (B = 0.103, p = 0.004) at baseline were associated with cognitive function at follow-up, even after adjusting for other risk factors. Furthermore, maintaining more teeth (B = 0.009, p = 0.004) and a stronger occlusal force (B = 0.020, p = 0.040) buffered cognitive decline. CONCLUSIONS: Number of teeth and occlusal force predict cognitive decline over 3 subsequent years in Japanese older adults aged 70 and 80 years.

Occlusal support predicts tooth loss in older Japanese people.

OBJECTIVES: Many older people lose their teeth. However, few studies have examined whether the number of remaining teeth or the amount of occlusal support is more important for tooth loss that occurs in older age after adjusting for systemic factors. The purpose of this study was to investigate comprehensively the factors related to tooth loss over a period of 6 years, including occlusal support in 70- and 80-year-old community-dwelling Japanese people. METHODS: This cohort study included 296 participants in the 70-year-old group and 232 in the 80-year-old group. The number of teeth of all participants was recorded at baseline and after 6 years, and the participants were divided into two groups according to the number of teeth lost (0 or 4 or more). Occlusal support was classified into three groups based on posterior occlusal support. Mean probing pocket depth, tooth brushing habits, frequency of dental check-ups, education level, economic status and systemic factors (carotid atherosclerosis, hypertension, diabetes mellitus, dyslipidemia, cognitive function and smoking habits) were evaluated. Multiple logistic regression analysis was performed to investigate the relationship of tooth loss with occlusal support and systemic factors. RESULTS: Logistic regression analysis revealed that mean probing pocket depth (odds ratio [OR] = 5.70, 95% confidence interval [CI] = 2.70-12.04, P < .01) and posterior occlusal support (reference = Eichner class A; Eichner B1-3, OR = 4.33, 95% CI = 1.54-12.17, P < .01; Eichner B4 or C, OR = 6.16, 95% CI = 1.17-32.44, P = .03) were associated significantly with the loss of four or more teeth. CONCLUSIONS: This study revealed that age itself is not a predictor of multiple tooth loss in community-dwelling older Japanese people. Deep mean probing pocket depth and a lack of posterior occlusal support were significantly associated with the loss of four or more teeth.

Lack of posterior occlusal support predicts the reduction in walking speed in 80-year-old Japanese adults: A 3-year prospective cohort study with propensity score analysis by the SONIC Study Group.

OBJECTIVE: To investigate the association between posterior occlusal support by residual teeth and the reduction in walking speed in 80-year-old Japanese adults using propensity score matching. BACKGROUND DATA DISCUSSING THE PRESENT STATUS OF THE FIELD: Previous studies have demonstrated an association between oral status and motor function; however, most of these studies had a cross-sectional design. MATERIAL AND METHOD: This study included 353 community-dwelling Japanese people aged 79-81 years. Low walking speed was defined as ≤0.8 m/s, and participants with a low walking speed at baseline were excluded. The participants were divided into two groups: with or without posterior occlusal support by residual teeth at baseline. Propensity score matching was used to reduce the effects of bias by matching participants with and without posterior occlusal support according to similar background factors at baseline. Conditional logistic regression was conducted to determine low walking speed at the 3-year follow-up, which included posterior occlusal support as an independent variable with matching data. RESULTS: Before matching for posterior occlusal support, significant differences existed between the groups in terms of sex, years of education, height, weight and grip strength. However, after matching, there was no significant difference between the groups in any characteristic. Logistic regression analysis showed that posterior occlusal support is a significant variable (odds ratio = 1.88; P = 0.04) associated with reduced walking speed. CONCLUSION: Lack of posterior occlusal support at baseline independently predicted the incidence of reduced walking speed over 3 years.

Impact of cognitive function on oral perception in independently living older people.

OBJECTIVES: Oral tactile perception is important for better mastication, appetite, and enjoyment of food. However, previous investigations have not utilized comprehensible variables thought to have negative effect on oral perception, including aging, denture wearing, and cognitive function. The aim of this study was to elucidate the impact of cognitive function on oral perception in independently living older individuals. MATERIALS AND METHODS: The study sample was comprised of 987 participants (466 males, 521 females; age 69-71 years). Oral examinations, assessments of cognitive function in preclinical level by Montreal Cognitive Assessment (MoCA)-J, and determination of oral stereognostic ability as an indicator of oral perception were performed. Related variables were selected by univariate analyses; then, multivariate logistic regression model analysis was conducted. RESULTS: Univariate analyses revealed that number of teeth, removable dentures usage, and cognitive function respectively had a significant relationship with stereognostic score. Next, the subjects were classified into good and poor perception groups (lowest 17.4%) according to oral stereognostic ability. Logistic regression analysis revealed that lower cognitive function was significantly associated with poor oral perception (OR = 0.934, p = 0.017) after controlling for other variables. CONCLUSIONS: Cognitive decline even in preclinical stage was associated with reduced oral perception after controlling for gender, tooth number and denture use in independent living older people. CLINICAL RELEVANCE: This study suggested that preclinical level of change in cognitive function affected oral perception. Dental practitioners and caregivers may need to pay attention to reduced oral perception among older people even if they do not have trouble in daily life.

Relationship between oral stereognostic ability and dietary intake in older Japanese adults with complete dentures.

PURPOSE: Oral stereognostic ability (OSA) is a useful indicator of oral perception to recognize food characteristics during mastication. Previous studies have shown associations between dietary intake and oral health status, such as taste perception. However, the effect of oral sensory ability on dietary intake is unclear. The purpose of this study was to investigate the association between oral sensory ability and dietary intake in older Japanese complete denture wearers. METHODS: This cross-sectional study included 164 participants aged 69-71 or 79-81years old, wearing both maxillary and mandibular complete dentures. OSA test was used to evaluate oral tactile perception. Diet during the preceding month was assessed using a self-administered diet history questionnaire. Multivariable linear regression analysis was conducted to assess the association between OSA score and food and nutrient intake after adjusting for age, sex, socioeconomic factors, and occlusal force. RESULTS: The bivariate analysis showed that OSA score was significantly and positively correlated with intake of green and yellow vegetables and negatively correlated with intake of cereals among examined foods. OSA score was also positively correlated with intake of vitamins A, B2, and C and α-tocopherol (as a substitute for vitamin E) among examined nutrients. After adjusting for age, sex, socioeconomic factors, and occlusal force, OSA score remained significantly associated with intake of green and yellow vegetables and α-tocopherol. CONCLUSIONS: OSA was significantly associated with intake of green and yellow vegetables in older complete denture wearers.

Influence of lack of posterior occlusal support on cognitive decline among 80-year-old Japanese people in a 3-year prospective study.

AIM: Previous studies have reported significant associations between tooth loss or periodontal status and cognitive function; however, animal experimental studies have shown that occlusion might be a more important factor in cognitive decline. The purpose of the present study was to investigate the influence of a lack of posterior occlusal support by residual teeth on the decline of cognitive function over a 3-year period among 80-year-old Japanese people. METHODS: Participants were community-dwelling older adults (n = 515, age 79-81 years). Cognitive function was measured using the Japanese version of the Montreal Cognitive Assessment. At baseline, participants were divided into two groups: those with and without posterior occlusal support. Participants whose Japanese version of the Montreal Cognitive Assessment score decreased by ≥3 points over the 3-year period were defined as the declined group. Logistic regression was carried out for the decline in Japanese version of the Montreal Cognitive Assessment scores, including dental status and possible risk factors as independent variables. RESULTS: More participants without posterior occlusal support tended to be in the cognitive decline group (49.4%) than in the maintained group (38.5%; χ2 -test, P = 0.02). Logistic regression analysis showed that a lack of posterior occlusal support was a significant variable (odds ratio 1.55, P = 0.03) for cognitive decline, even after adjusting for other risk factors. However, the number of teeth or mean periodontal pocket depth was not significantly correlated with cognitive decline. CONCLUSIONS: The present findings suggest that a lack of posterior occlusal support predicted the incidence of cognitive decline, even after adjusting for possible risk factors in community-dwelling old-old people. Geriatr Gerontol Int 2018; 18: 1439-1446.