Low tongue pressure and depression using Kihon Checklist for assessing frailty status among community-dwelling Japanese older adults: A pilot study.

BACKGROUND: Evaluation of low tongue pressure is used to diagnose oral hypofunction. The pathophysiology of oral hypofunction is hypothesized to be associated with oral dysfunction related to ageing. Depression in older adults is a major problem and is related to handgrip strength, which is related to tongue pressure. We hypothesized that low tongue pressure could indicate depression mood in community-dwelling older adults. OBJECTIVES: This study aimed to measure maximum tongue pressure and compare it to the responses to the Kihon Checklist (KCL), which is used to check mental and physical deterioration of community-dwelling older adults. METHODS: A total of 49 community-dwelling independent older adults with stable dental condition (23 men, 26 women; median age, 79 years) answered the KCL, which contained questions on frailty status, cognitive function, nutritional and sarcopenia status. Oral function was measured to assess oral hypofunction. The relationship between tongue pressure differences and frailty status, cognitive function, nutritional and sarcopenia status was analysed using logistic regression analyses after adjusting for age and sex. RESULTS: Nine participants (6 men and 3 women; median age, 81 years) had a tongue pressure <23.0 kPa, which was the lowest limit of the standard value of maximum tongue pressure in patients aged ≥70 years. Logistic regression analyses showed that only Question 21, which is related to a lack of fulfilment in daily life, was significantly associated with low tongue pressure (p = .027). CONCLUSION: Low tongue pressure may be associated with sociopsychological factors in older adults.

Associations of sex, age, and number of remaining teeth with performance on oral hypofunction tests.

INTRODUCTION: Oral hypofunction comprises seven aspects of oral condition, including oral hygiene, oral dryness, bite strength, tongue-lip motor function, tongue pressure, masticatory function, and swallowing function. Each of these seven has a single diagnostic criterion; however, the use of a single indicator without consideration of sex, age, or other factors is controversial. The purpose of this study was to evaluate the association between the oral hypofunction test and sex, age, and number of remaining teeth. METHODS: The study was conducted at 12 facilities by the members of the Japanese Society of Geriatric Dentistry during April to December 2019. The participants comprised 181 healthy older adults aged 65 years and over (56.9% female; age range 65-95 years) who regularly visited these facilities. All tests of oral function and oral status available in Japan were performed on the participants, and the association between these tests and sex, age, and number of remaining teeth was examined. RESULTS: Sex differences were observed in masticatory function, bite force, lip closure force, jaw-opening force, oral diadochokinesis "ka," and tongue coating index (p < .05). In men, age was weakly (r = 0.20-0.40) associated with masticatory function, jaw-opening force, maximum tongue pressure, oral diadochokinesis, and swallowing function. In women, the number of remaining teeth, masticatory function, jaw-opening force, and oral diadochokinesis "ta" and "ka" was also weakly associated with age. CONCLUSIONS: Performance on the oral hypofunction test differs by sex, age, and number of remaining teeth. This means that the current single criterion for evaluation requires caution in its interpretation.

Factors Associated with Food Form in Long-Term Care Insurance Facilities.

We examined factors related to dietary intake status (food form) of long-term care facility (LTCF) residents to identify factors related to proper food form choice for older individuals requiring nursing care. We surveyed 888 residents from 37 LTCFs in Japan. We evaluated basic information (age, sex, body mass index [BMI]), food form (swallowing-adjusted diet class), Barthel Index (BI), Clinical Dementia Rating (CDR), simply evaluated eating and swallowing functions, the number of present/functional teeth, oral diadochokinesis, repetitive saliva swallowing test (RSST), and modified water swallowing test. To clarify factors associated with food form, participants who had good nutrition by oral intake were categorized into the dysphagic diet (DD) and normal diet (ND) groups. Multi-level analyses were used to detect oral functions associated with food form status. Among objective assessments, BMI (odds ratio [OR] 0.979, 95% confidence interval [CI] - 0.022- to 0.006, p = 0.001), BI (OR 0.993, 95% CI - 0.007 to - 0.004, p < 0.001), CDR 3.0 (OR 1.002, 95% CI 0.002‒0.236, p = 0.046), present teeth (OR 0.993, 95% CI - 0.007 to - 0.001, p = 0.011), functional teeth (OR 0.989, 95% CI - 0.011 to - 0.005, p < 0.001), and RSST (OR 0.960, 95% CI - 0.041 to - 0.007, p = 0.006) were significantly associated with DD vs ND discrimination. Simple evaluations of coughing (OR 1.056, 0.054‒0.198, p = 0.001) and rinsing (OR 1.010, 0.010‒0.174, p = 0.029) could also discriminate food form status. These simple evaluations provide insight into the discrepancies between food form status and eating abilities of LTCF residents. Periodic evaluations by the nursing caregiver may help to prevent aspiration by older individuals with dysphagia.

Pneumonia incidence and oral health management by dental hygienists in long-term care facilities: A 1-year prospective multicentre cohort study.

OBJECTIVE: To investigate the association between oral health management (OHM) by dental hygienists and the occurrence of pneumonia, and determine the effectiveness of OHM in pneumonia prevention. BACKGROUND: In long-term care facilities in Japan, the need for professional OHM is increasing with an increase in the number of severely debilitated residents. MATERIALS AND METHODS: A 1-year prospective multicentre cohort study was conducted using data from 504 residents (63 men; mean age: 87.4 ± 7.8 years) in Japanese long-term care facilities. Basic information, medical history, willingness to engage in oral hygiene behaviour, need for OHM and oral conditions were investigated at baseline. In addition, information on the occurrence of pneumonia was collected using a follow-up survey after one year. A Poisson regression analysis with robust standard errors was conducted, with pneumonia as the dependent variable, and factors associated with OHM and pneumonia occurrence as explanatory variables. RESULTS: Overall, 349 (69.2%) residents required OHM by dental hygienists during that year of follow-up. Of those, 238 (68.2%) were provided with OHM, and 18 (7.5%) developed pneumonia. Among the 111 patients (31.8%) who were not provided with OHM, 21 (18.9%) developed pneumonia. The OHM group had lower pneumonia rates than the non-OHM group (prevalence rate ratio: 0.374; 95% CI: 0.210-0.665). CONCLUSION: Oral health management by dental hygienists was associated with a lower incidence of pneumonia among residents of long-term care facilities, underlining the importance of professional OHM for such individuals. It is recommended that OHM be practised routinely in long-term care facilities.

Age-related changes in oral tactile and thermal sensation throughout adulthood.

Although the life expectancy of women is over 80 years in many countries, oral sensation has scarcely been compared between adults ≥ 80 years and younger age groups. The purpose of this study was to clarify age-related changes in oral sensation throughout adulthood. After exclusion of individuals with factors that might have confounded somatosensory performance, 123 female participants were divided into four age groups: 20-39 years, 40-59 years, 60-79 years, and 80-96 years. Perceptions of tactile and thermal sensations were examined at points on the anterior and posterior palate, anterior and posterior tongue, lower labial-attached gingiva, lower lip, and buccal mucosa; two-point discrimination was examined only on the tongue. The tactile and two-point discrimination thresholds for the anterior and posterior tongue were significantly higher in the 80-96-year-old group than in any other age group (p < 0.05). The tactile threshold for the buccal mucosa was significantly higher in the 80-96-year-old group than in the 60-79-year-old group (p < 0.05). The percentage of participants able to perceive a warm stimulus (50 °C) in the buccal mucosa was significantly lower in the 80-96-year-old group than in the 20-39-year-old group (p < 0.05). Only the topography of the warm sensation perception changed with age. This cross-sectional study suggests that oral tactile and thermal sensation for warm stimuli deteriorates with age in a site-specific manner, especially after the age of 80 years, but the same does not occur with cool stimuli.

Association between buccal mucosa ridging and oral or occlusal status among older people.

OBJECTIVES: This study aimed to evaluate the association between buccal mucosa ridging and oral or occlusal statuses among older people. SUBJECTS AND METHODS: This cross-sectional study examined 262 independent older people (mean age, 74.2 ± 5.9 years) who participated in the Kyoto Elderly Physical Fitness Measurement Research Project. The predictor variables were oral statuses (number of present teeth and torus palatinus, torus mandibularis, temporomandibular joint noise, clenching, or grinding) and oral functions (occlusal pressure, cheek pressure, oral diadochokinesis, and tongue pressure). The outcome variable was the buccal mucosa ridging status (presence or absence). Additional variables were age, sex, body mass index, grip strength, and wearing dentures. We compared these variables between participants with and without buccal mucosa ridging using a univariate analysis and multiple logistic regression analysis. RESULTS: Buccal mucosa ridging was present in 177 (67.6%) people. Multiple logistic regression analysis revealed a close association of buccal mucosa ridging with torus mandibularis, tooth clenching and grinding and occlusal pressure, and cheek pressure. CONCLUSIONS: Over 50% of the participants showed buccal mucosa ridging; this was significantly associated with higher cheek pressure, lower occlusal pressure, torus mandibularis, and tooth clenching and grinding.

Prevalence of Torus Mandibularis in Young Healthy Dentate Adults.

PURPOSE: There have been only a few reports on the prevalence of torus mandibularis (TM) in young adult patients, and TM can have various adverse effects on oral and occlusal states in middle-age patients. This study was designed to determine the association between TM status and oral and occlusal states in young healthy dentate adults. MATERIALS AND METHODS: This was a cross-sectional study; the sample population included students at Hiroshima University (Hiroshima, Japan) who participated for practical education. The predictor variables in this study included oral symptoms (temporomandibular joint noise, tooth clenching and grinding, buccal mucosa ridging, dental attrition, and tongue habit), oral anatomy (occlusal vertical dimension), and oral function (average occlusal pressure, occlusal contact area, and maximum voluntary tongue pressure). The outcome variable was TM status (present or absent). Additional variables were demographic in nature and included age, number of residual teeth, body weight, and gender. These variables were compared among participants with and without TM using univariate analysis and multiple logistic regression analysis. Statistical analyses were carried out using SPSS Statistics 19 for Windows (IBM Corp, Armonk, NY); a P value less than .05 was considered significant. RESULTS: Of 204 participants included in the study, 50% were men and 50% were women. The mean age was 22.4 ± 2.7 years. TM was present in 119 (58.3%). Multiple logistic regression analysis showed that TM status was associated with dental attrition and occlusal contact area (P < .05). CONCLUSIONS: This study showed that TM was present in more than half the young healthy dentate participants and was closely associated with dental attrition and occlusal contact area. This study will provide readers with useful information to help prevent the development of TM before middle age.

Factors related to skeletal muscle mass in the frail elderly.

It is important for the elderly to maintain their skeletal muscle mass, which in turn helps to maintain physical functions. This study aimed to clarify factors related to skeletal muscle mass maintenance. Home-bound elderly (94 men and 216 women), at least 75 years of age, attending a day-care center in Tokyo, were enrolled in this study. Dentists specializing in dysphagia rehabilitation evaluated skeletal muscle mass, occlusal status and swallowing function. Physical function, cognitive function and nutritional status were also evaluated by interviewing caregivers. Correlations of skeletal muscle mass with various factors were determined in each gender group. Multiple regression analysis revealed that skeletal muscle mass was significantly related to nutritional status in both men and women. In men, there was a significant difference in skeletal muscle mass between those with and without occlusion of the natural teeth. Our results suggest that dental treatments and dentures would be useful for maintaining skeletal muscle mass, especially in men.

One-leg standing time with eyes open: comparison between the mouth-opened and mouth-closed conditions.

OBJECTIVE: Many studies report a significant relationship between the one-leg standing time with the eyes open and the occlusal relationship. To determine the association between proprioception (the periodontal membrane vs muscle spindle) to the one-leg standing time, the authors compared the one-leg standing time with eyes open between mouth-opened and mouth-closed conditions. METHODS: The study participants were 107 healthy, elderly patients. The authors measured the one-leg standing time with eyes open between mouth-opened and mouth-closed conditions. RESULTS: The one-leg standing time was significantly shorter with the mouth opened (21·1±19·1 seconds) than with the mouth closed (25·1±21·4 seconds). Patients whose one-leg standing time was equal or shorter with the mouth opened than with the mouth closed were not different from the other patients with regard to age, handgrip strength, BMI, and the number of remaining teeth. DISCUSSION: The vertical mandibular position may affect body balance.

Changes in oral health status in terminal cancer patients during the last weeks of life.

BACKGROUND: Many studies have shown deterioration of the oral health environment in palliative care patients; however, most of these studies are cross-sectional. In this longitudinal observational study, we aimed to determine the oral symptoms and how they change in palliative care patients. METHODS: The participants were 82 patients (37 men, 45 women) admitted to two palliative care units in Japan between January 2018 and December 2021. The oral condition was evaluated once a week from the time of admission using the Oral Health Assessment Tool (OHAT) and performance status (PS). Friedman tests were performed on the OHAT and PS scores at 1, 2, and 3 weeks before the week of death. In addition, the Bonferroni method was used to determine how many weeks before death the changes occurred. RESULTS: PS continuously deteriorated from three weeks before death. The total OHAT score 2 weeks before death (3.44±2.10) was significantly different compared to that in the week of death (4.37±2.45). In terms of oral conditions, the properties of the saliva changed, and dry mouth became obvious. CONCLUSIONS: The results of this study revealed that the oral environment of palliative care patients became significantly dry 2 weeks before death, suggesting that it may be useful for predicting the stage of death.

Prospective Observational Study for the Comparison of Screening Methods Including Tongue Pressure and Repetitive Saliva Swallowing With Detailed Videofluoroscopic Swallowing Study Findings in Patients With Acute Stroke.

BACKGROUND: Simple, noninvasive, and repeatable screening methods are essential for assessing swallowing disorders. We focused on patients with acute stroke and aimed to assess the characteristics of swallowing screening tests, including the modified Mann Assessment of Swallowing Ability score, tongue pressure, and repetitive saliva swallowing test (RSST), compared with detailed videofluoroscopic swallowing study (VFSS) findings to contribute as a helpful resource for their comprehensive and complementary use. METHODS AND RESULTS: We enrolled first-ever patients with acute stroke conducting simultaneous assessments, including VFSS, modified Mann Assessment of Swallowing Ability score, tongue pressure measurement, and RSST. VFSS assessed aspiration, laryngeal penetration, oral cavity residue, vallecular residue, pharyngeal residue, and swallowing reflex delay. Screening tests were compared with VFSS findings, and multiple logistic analysis determined variable importance. Cutoff values for each abnormal VFSS finding were assessed using receiver operating characteristic analyses. We evaluated 346 patients (70.5±12.6 years of age, 143 women). The modified Mann Assessment of Swallowing Ability score was significantly associated with all findings except aspiration. Tongue pressure was significantly associated with oral cavity and pharyngeal residue. The RSST was significantly associated with all findings except oral cavity residue. Receiver operating characteristic analyses revealed that the minimum cutoff value for all VFSS abnormal findings was RSST ≤2. CONCLUSIONS: The modified Mann Assessment of Swallowing Ability is useful for broadly detecting swallowing disorders but may miss mild issues and aspiration. The RSST, with a score of ≤2, is valuable for indicating abnormal VFSS findings. Tongue pressure, especially in oral and pharyngeal residues, is useful. Combining these tests might enhance accuracy of the swallowing evaluation.

Association between denture use and food form in older adults requiring long-term care: A multicenter cross-sectional study.

PURPOSE: This study aimed to determine whether denture use contributes to maintaining and improving food forms in long-term care facility (LTCFs) residents. METHODS: In 888 residents of 37 LTCFs in Japan, the following were investigated: nutritional intake status, food forms, age, sex, Barthel index (BI), clinical dementia rating (CDR), number of teeth present, number of occlusal supports, swallowing function, and use of dentures. Among all residents, those who were well-nourished and had ≤9 occlusal supports were analyzed. Based on standardized criteria, the food forms consumed by the subjects were divided into two groups: dysphagia and normal diet, which were further classified into four levels. Analysis was performed using a generalized estimation equation with the four levels of food forms as dependent variables and age, sex, BI, CDR, presence of dysphagia, number of teeth present, and use of dentures as independent variables. RESULTS: The final analysis included 622 (70.0%) residents. Of these, 380 (61.1%) used dentures. The analyses revealed that food form was significantly associated with age (adjusted odds ratio [OR], 0.98), BI (OR, 1.04), number of teeth present (OR, 1.03), presence of dysphagia (OR, 0.44), and use of dentures (OR, 2.82). CONCLUSIONS: Denture use was associated with food forms among Japanese LTCF residents. This indicates that the use of dentures is related to the maintenance of food forms, even in the elderly who participate in few activities of daily living, have reduced cognitive function, and require long-term care.

The evaluation of oral health in stroke patients.

OBJECTIVE: As tooth loss has been suggested as a potential risk factor for stroke, oral examinations were carried out on stroke patients to review the oral condition of those patients. METHOD: The subjects were patients consecutively discharged from the recovery rehabilitation unit of Hiroshima City General Rehabilitation Center between April 2008 and December 2009. All patients were offered oral examination and 358 of 443 patients accepted. Patients receiving dental examination were divided into two groups: one group comprising stroke patients and the second, patients with other disorders. These two groups were then compared for the number of remaining teeth by age group. RESULTS: Among the examined patients, the number of remaining teeth in stroke patients in their 50s and 60s was significantly lower than for patients in corresponding age groups (18.4 ± 9.4 vs. 24.5 ± 5.4 and 18.3 ± 9.2 vs. 22.2 ± 7.2, respectively, with p < 0.05 for both age groups) who were hospitalised for other conditions. In addition, the number of remaining teeth in stroke patients in their 50s was also significantly lower than the number reported in the Survey of Dental Diseases (24.1 ± 6.1; p < 0.05). CONCLUSION: The results of this study suggest an association between tooth loss and early occurrence of stroke.

Maximal voluntary tongue pressure is decreased in Japanese frail elderly persons.

BACKGROUND AND OBJECTIVE: To quantitatively estimate tongue function, we developed a handy device for intraoral pressure measurement. The objective of this study was to assess maximum voluntary tongue pressure (MVTP) in Japanese frail elderly persons receiving nursing care services. MATERIALS AND METHODS: The study included 42 men and 87 women, aged 58-100 years. To record MVTP, the participants were asked to compress the balloon (diameter: 18 mm) of the disposable intraoral pressure probe onto their palates for 7 s using the maximum voluntary effort of the tongue. Pressures were recorded three times at 1 min intervals. RESULTS: Maximum voluntary tongue pressure was successfully measured in 111 persons. Mean (standard deviation) MVTP was 18 (12) kPa, with a range of 0-63 kPa. The remaining 18 persons could not accurately follow our instructions and MVTP could not be measured. CONCLUSION: In comparison with the reported standard value using the same device, the frail elderly persons included in our study were found to exert less MVTP than healthy dentate individuals. These results suggest the need for proper quantitative evaluation of oral function, including tongue capacity, at nursing care facilities.

Relationship between Food Crushing and Oral Function in Older Adults Requiring Nursing Home Care: A Pilot Study.

We investigated how jelly is crushed and examined the relationship between tongue pressure and tongue food crushing ability among older adults requiring nursing home care. Seventy-two participants were instructed to freely crush the test foods soft jelly (SJ) and hard jelly (HJ). We visually evaluated the crushability of the test food and identified the intraoral tissues (active sites) used to crush the test food. The active sites were consistent for all participants for both SJ and HJ, and they included the maxillary and mandibular teeth in 41 participants, teeth and residual ridges in 15 participants, maxillary and mandibular residual ridges in 10 participants, and tongue and palate in six participants. Two participants failed to crush the SJ; the active sites in both participants were the tongue and palate. No participant using the tongue and palate as active sites could crush the HJ. Furthermore, 64 participants could crush the SJ and 23 could crush the HJ using the tongue and palate. The cutoff value of the tongue pressure for crushability of the HJ was 22.0 kPa. Assessing tongue pressure and intraoral active sites involved in food crushing could help determine an appropriate diet for older adults requiring nursing home care.

Observational Variables for Considering a Switch from a Normal to a Dysphagia Diet among Older Adults Requiring Long-Term Care: A One-Year Multicenter Longitudinal Study.

This one-year multicenter longitudinal study aimed to assess whether older adult residents of long-term care facilities should switch from a normal to a dysphagia diet. Using the results of our previous cross-sectional study as baseline, older adults were subdivided into those who maintained a normal diet and those who switched to a dysphagia diet. The explanatory variables were age, sex, body mass index (BMI), Barthel Index, clinical dementia rating (CDR), and 13 simple and 5 objective oral assessments (remaining teeth, functional teeth, oral diadochokinesis, modified water swallowing test, and repetitive saliva swallowing test), which were used in binomial logistic regression analysis. Between-group comparison showed a significantly different BMI, Barthel Index, and CDR. Significant differences were also observed in simple assessments for language, drooling, tongue movement, perioral muscle function, and rinsing and in objective assessments. In multi-level analysis, switching from a normal to a dysphagia diet was significantly associated with simple assessments of tongue movement, perioral muscle function, and rinsing and with the objective assessment of the number of functional teeth. The results suggest that simple assessments can be performed regularly to screen for early signs of discrepancies between food form and eating/swallowing functions, which could lead to the provision of more appropriate food forms.

Relationship between weight loss and regular dental management of older adults residing in long-term care facilities: a 1-year multicenter longitudinal study.

PURPOSE: This study aimed to determine the association between home visits by a dentist and regular oral hygiene management by a dental hygienist (regular dental management: RDM) and weight loss among older adults in long-term care facilities. METHODS: A total of 468 older residents from 26 Japanese long-term care facilities participated in two surveys in 2018 and 2019. Participants were divided into two groups based on their diet during the baseline survey (regular diet, n = 256; dysphagia diet, n = 212). Participants with a regular diet were further divided into those who exhibited a weight loss ≥ 5% over 1 year (weight loss group: n = 77) and those with a weight loss < 5% (consistent weight group: n = 179). The explanatory variables were age, sex, baseline weight, Barthel index, and clinical dementia rating, as well as the patients' medical history of pneumonia, stroke, diabetes, and depression (which is reportedly associated with weight). Additionally, a Poisson regression with robust standard error, was carried out to analyze the explanatory variables, namely the prevalence of RDM noted during the study and functional teeth (which seemed to affect weight loss). RESULTS: A multivariate analysis revealed that older residents' lack of RDM, clinical dementia assessment, and their history of pneumonia (prevalence rate ratio: 0.35, 95% confidence interval 0.24-0.95) were all significantly associated with weight loss when on a regular diet. CONCLUSION: Thus, weight loss and RDM were related to each other. Weight loss may be suppressed by incorporating RDMs during the early nursing care for older residents on regular diets.

Association between buccal mucosa ridging and oral feature/symptom and its effects on occlusal function among dentate young adults in a cross-sectional study of Japan.

Objective: The purpose of this study was to assess the distinction in oral features/symptoms and occlusal function between young dentate individuals with and without buccal mucosa ridging (BMR). Methods: This cross-sectional study included 200 young adults. The outcome variable was BMR state. The predictor variables were oral features/symptoms (torus palatinus, torus mandibularis, temporomandibular joint noise, bruxism, tongue thrusting habit, number of teeth present, and occlusal vertical dimension) and oral function (occlusal force, occlusal contact area, occlusal pressure, tongue pressure). These variables were compared among participants with and without BMR using univariate and multiple logistic regression analysis. Results: There were 119 participants with BMR and 81 without BMR. Multiple logistic regression analysis revealed that BMR was closely associated with bruxism, occlusal vertical dimension, and occlusal pressure. Discussion: Oral/occlusal changes of increased bruxism, lower occlusal vertical dimension, and lower occlusal pressure constitute the major causes of BMR.

Association between masticatory ability and oral functions.

BACKGROUND: Mastication is the process of breaking ingested food with the teeth and mixing it with saliva to form a mass that is easy to swallow. However, few studies have reported on oral functions, such as occlusal force, tongue pressure, and mastication. The purpose of this study was to evaluate the association between masticatory function and oral functions, such as occlusal force and tongue pressure. MATERIAL AND METHODS: In this study, there were 113 patients (41 men and 72 women; mean age, 68.4 ± 11.3 years) who visited dentists at the Hiroshima University Hospital, Hiroshima, Japan between April 2015 and November 2018. Masticatory function of the patients was evaluated using a masticatory ability test system. In addition, occlusal force was measured using a pressure-sensitive film and the maximum tongue pressure was measured with a tongue pressure measuring device according to a conventional method. The relationship of masticatory ability with occlusal force and tongue pressure was examined using multivariate analysis while considering patients' age, gender, and the number of remaining teeth. RESULTS: Masticatory ability was significantly related to occlusal force, maximum tongue pressure, age, body mass index, the number of remaining teeth, and occlusal contact area (p< 0.05). Multiple regression analysis identified that masticatory ability was significantly associated (p< 0.05) with occlusal force and maximum tongue pressure. CONCLUSIONS: Masticatory ability was significantly associated with occlusal force and maximum tongue pressure, indicating that the large muscle mass in the oral cavity is indispensable for improving masticatory function. Key words:Mastication, tongue pressure, occlusion force, oral function.

Association between salivary alpha-amylase and subjective and objective oral parafunctions in community-dwelling elderly individuals.

BACKGROUND/PURPOSE: Stress in the elderly is caused by loss of physical and psychological health. Although there have been many reports on the intraoral environment affecting physical health, few reports exist on stress and the intraoral environment in the elderly. The aim of this study was to investigate the relationship between salivary α-amylase as an index of stress value and the intraoral environment. MATERIALS AND METHODS: Three hundred and nineteen participants were community-dwelling independent individuals over 65 years old. The outcome variable was salivary α-amylase. After measurement, salivary α-amylase was classified into four groups (0 = 0-30, 1 = 31-45, 2 = 46-60, 3 = 61-200). The predictor variables were physical status (which includes age and male body-mass index) and subjective and objective symptoms (which include present teeth, torus palatinus, torus mandibularis, temporomandibular joint noise, bruxism, and dental attrition). These variables were compared among participants using univariate analysis and multiple logistic regression analysis. RESULTS: The participants included 77 men and 242 women, with a mean age of 75.8 ±â€¯5.4 years (65-94 years). Although temporomandibular joint noise and dental attrition were significantly positively correlated with salivary α-amylase, bruxism was significantly negatively correlated with salivary α-amylase (p < 0.05). Stepwise regression analysis revealed a significant relationship between salivary α-amylase and temporomandibular joint noise, bruxism, and dental attrition. CONCLUSION: High salivary α-amylase is associated with a high rate of temporomandibular joint noise and dental attrition, and a low rate of bruxism among elderly participants.