The Association of Walking Ability with Oral Function and Masticatory Behaviors in Community-Dwelling Older People: A Cross-Sectional Study

Background: Consuming a variety of foods is believed to promote thorough chewing; however, it remains unclear whether individuals who consume various foods actually chew them thoroughly. Therefore, this study aimed to examine the association between dietary variety and masticatory behaviors, measured using wearable devices, among community-dwelling older adults. Methods: Participants were from the Itabashi Longitudinal Study of Aging, meeting the eligibility criteria, including the ability to exchange messages via smartphone or computer. Masticatory behaviors (number of chews, chewing duration, and speed) and meal photo data were objectively measured using an ear-worn bite sensor and its application for two or three meals per day for at least three days at home. The "modified Dietary Variety Score (m-DVS)" (range 0-10, with higher values indicating greater dietary variety) was calculated by registered dietitians. Generalized linear mixed models assessed the association between m-DVS as the exposure variable and masticatory behaviors as the outcome variable. Covariates included sociodemographic status, health behavior, health status, oral health, and oral function. Results: Five hundred and eighty-seven mealtime data entries from 63 participants were included in the analysis. The m-DVS was significantly positively associated with the number of chews (cycles, unstandardized regression coefficient = 116.5, 95% confidence interval [CI] = 85.2 to 147.8) and chewing duration (min, unstandardized regression coefficient = 1.7, 95% CI = 1.3 to 2.2). Conclusions: Consuming more varied food groups was associated with more chews and longer chewing duration among community-dwelling older adults, potentially promoting thorough chewing.

BackgroundPatients with mandibular prognathism exhibit not only its characteristic maxillofacial morphology but also discrepancies in stomatognathic function, and understanding this morphology and function is vital for establishing a plan for surgical orthodontic treatment or providing guidance for recovery after orthognathic surgery. However, few studies have yet addressed the objective evaluation of masticatory function before and after surgical orthodontic treatment. In particular, the masticatory behaviors that show how you chew in your daily meals, including the number of chews, chewing rate, and posture during chewing, has not yet been fully studied in patients with mandibular prognathism. The aim of this study was to compare the masticatory behaviors of patients with mandibular prognathism with that of patients with individualized normal occlusion, to clarify the characteristics of masticatory behaviors in mandibular prognathism and to search for a relationship with maxillofacial morphology.MethodsParticipants were 23 patients (12 men, 11 women; mean age 17.9 years) with mandibular prognathism (patient group) and 23 patients (12 men, 11 women; mean age 24.4 years) with normal occlusion that had been achieved by orthodontic treatment (control group). Masticatory behaviors were measured by a wearable device fitted to each participant’s right ear. Parameters such as number of chews, chewing rate, number of chews per bite, mealtime, and head and neck posture were recorded, while participants consumed a 100-g rice ball. Body mass index, occlusal contact area, and lateral cephalograms were also measured, and their associations with masticatory behaviors were investigated.ResultsIn patient group, the number of chews was lower, mealtime was shorter, and the head and neck were tilted further forward. There was a significant positive correlation between overjet and anteroposterior head and neck posture and a significant negative correlation between overbite and anteroposterior head and neck posture.ConclusionDue to morpho/functional discrepancies in the stomatognathic system, patient group chewed fewer times and for a shorter time and leaned further forward while chewing. The characteristics of the masticatory behaviors of patients with mandibular prognathism identified in the present study may be helpful when devising plans for changing behavior before and after orthodontic treatment or orthognathic surgery.

Background: Aging causes a decline in various functions. Among older adults, deteriorations in oral function might interfere with their diet. However, the insight into whether oral function improvement affects older adults' diet remains unclear.Aim: To investigate whether oral function improvement by an intervention can affect the diet of community-dwelling aged people needing any care.Participants and Methods: This study enrolled 16 community-dwelling older people aged 65 years who were certified to require support care level 1 or 2. We measured the participants' oral function (tongue pressure, oral diadochokinesis, and masticatory force) and used questionnaires to collect data on attributes and diet before and after the intervention, which comprised four oral exercises once a day for 3 months at their own homes. The effect of the intervention was determined using the paired t-test and Wilcoxon signed-rank sum test.Results: Tongue pressure (p < 0.001), /pa/syllable (p = 0.027), /ta/syllable (p = 0.046), and masticatory force (p = 0.012) significantly improved after the intervention. Conversely, the/ka/syllable (p = 0.083) and ingestion frequency (p = 0.107 − 0.773) did not change significantly.Conclusions: Oral function training improved the oral function of older adults but could not change their dietary habits. Diet improvement may require dietary counseling together with oral exercise.

Recent longitudinal studies have shown the influence of multiple tooth loss on cognitive impairment, and earlier studies suggested that periodontal disease was related to cognitive decline. Tooth loss is associated with reduced masticatory function, which may affect stimulation of the central nervous system and dietary intake. Although some studies have reported a relationship between chewing ability and cognitive function, no studies have examined this area in terms of objective oral function. The aim of this study was to examine the association of occlusal force with cognitive decline in the preclinical stage among older people with higher-level functional capacity. This cross-sectional study for community-dwelling older people living in urban and rural areas in Japan examined 994 persons in the 70-y group (age range, 69-71 y) and 968 persons in the 80-y group (age range, 79-81 y). Retention of higher-level competence was defined according to the Tokyo Metropolitan Institute of Gerontology Index of Competence. Cognitive function was measured with the Japanese version of the Montreal Cognitive Assessment (MoCA-J). Oral status and function were assessed by the number of remaining teeth, periodontal pocket depth, and maximal occlusal force. Associations between the MoCA-J score and occlusal force were examined by bivariate and multivariate analysis. Approximately one-half of the participants retained higher-level functional capacity and were included in the analysis. Multiple regression analysis showed that occlusal force was significantly related to cognitive function after controlling for possible predictors including age, sex, socioeconomic status, medical condition, and handgrip strength. The number of remaining teeth and periodontal pocket depth were not significantly associated with cognitive function. Among community-dwelling older people with retained competence, maximal occlusal force was positively associated with their cognitive function. These results suggest that oral function might be a predictor for preclinical cognitive decline. Knowledge Transfer Statement: Multiple regression analysis showed that occlusal force was significantly related to cognition after controlling for possible predictors including handgrip strength as an indicator of general muscle strength, suggesting the independence of oral function. The number of remaining teeth did not have this association. The majority of older people have lost teeth and have received prosthodontic treatment, and their occlusal force is determined not only by the number of remaining teeth but also by prosthetic rehabilitation. These results can be used by clinicians focusing on prevention of tooth loss among the entire population, as well as to encourage partially edentulous and fully edentulous patients to restore their oral function with prostheses in order to eliminate a possible risk factor for cognitive impairment.

This study investigated the effects of differences in oral function and depressive tendencies on nutritional status in older adults requiring support or low-level care. In 106 older adult participants residing in nursing/care homes or participating in community-level preventive care activities, the Mini Nutritional Assessment-Short Form (MNA®-SF) for nutritional status and oral diadochokinesis (ODK), tongue pressure, and repetitive saliva swallowing test (RSST) for oral function, 15-item Geriatric Depression Scale (GDS), Diet-Related Quality of Life Scale-Short Form (DRQOL-SF), and Functional Independence Measure (FIM) were administered. Basic information, including cognitive function, was evaluated. Hierarchical MNA (dependent variable)-based multiple regression analysis was performed, followed by path analysis using factors with significant associations with MNA scores. RSST, ODK, tongue pressure, FIM, and DRQOL were positively correlated with MNA scores and GDS was negatively correlated. Hierarchical multiple regression demonstrated associations with tongue pressure, GDS, FIM, DRQOL scores, and gender. Path analysis confirmed significant paths from tongue pressure to MNA, tongue pressure to FIM, and FIM to MNA (P < .001). Significant paths were confirmed from GDS to MNA (P < .01), from DRQOL to MNA (P < .05), and from gender to MNA (P < .01). Tongue pressure, GDS, FIM, DRQOL scores, and gender were identified as factors that directly affect MNA. Tongue pressure showed the greatest effect and indirectly affected MNA via FIM. These findings emphasize the importance of early detection of low nutritional risk for preventing depression and oral function deterioration, and of evaluation of dietary satisfaction and improvement of quality of life in diets.

The aim of this study was to analyze the data from a cohort study of community-dwelling older people to clarify the impact of low tongue pressure on the onset of malnutrition. The analysis was divided into a baseline and a longitudinal analysis. The baseline analysis included 765 people (median age: 74 years; 276 men and 489 women), and the longitudinal analysis included 100 people (median age: 72 years; 33 men and 67 women). The baseline analysis showed that tongue pressure and the diagnosis of low tongue pressure using a cut-off of 30kPa were associated with the risk of malnutrition (tongue pressure: odds ratio [OR] = 0.972, 95% confidence interval [95% CI] = 0.953-0.992, p = 0.006; the diagnosis of low tongue pressure: OR = 1.555, 95% CI = 1.050-2.302, p = 0.027). In the longitudinal analysis, tongue pressure and the diagnosis of low tongue pressure at baseline were associated with the onset of the risk of malnutrition after 4 years (tongue pressure: OR = 0.952, 95% CI = 0.907-0.998, p = 0.041; the diagnosis of low tongue pressure: OR = 2.698, 95% CI = 1.148-6.341; p = 0.023). In community-dwelling older people, low tongue pressure could increase the risk of future malnutrition.

Background Maintaining good oral function is one of the goals of dental treatment. The Japanese national insurance system newly introduced the concept of management of oral function according to the life stage. For the application of management of oral functions of the elderly, seven kinds of examination is a must for the diagnosis: xerostomia, oral hygiene status, maximum occlusal pressure, tongue and labium function, tongue pressure, chewing ability, and swallowing function. We analyzed the relationship between oral functions and supplied food consistency. Methods Oral functions and supplied food consistency of sixty-nine institutionalized elderly were investigated. There were 13 men and 56 women, and their mean age was 86.23 ± 7.02. Oral functions were measured and evaluated according to the Japanese insurance system. Data were analyzed by item response theory analysis, ROC analysis, and decision analysis. Results By the item response theory analysis, tongue pressure and swallowing functions had high discrimination ability. The subjects who had malfunction of the tongue and labium all had processed food. The subjects with difficulty in swallowing, even without malfunction of the tongue and labium, all had processed food. Conclusion Supplied food consistency may depend on the oral functions. However, as oral function has some dimension, a systematic evaluation system is necessary to decide the supplied food consistency.

Oral function deterioration attributed to ageing and medications is one of the main contributory factors of dysphagia. Therefore, oral health management is essential in older patients with schizophrenia. However, no previous studies have evaluated the oral function in patients with schizophrenia. We surveyed patients with schizophrenia to identify factors associated with ageing-related variations in oral function. This cross-sectional study included 34 male patients diagnosed with schizophrenia who were hospitalised at a psychiatric hospital between July and September 2021 and underwent a screening examination during dental care. The survey items included basic information, oral hygiene information, oral (oral diadochokinesis [ODK] and tongue pressure), physical function, and nutritional status. Thirty-six male community-dwelling older individuals were included as controls, and their outcomes were compared with those of patients with schizophrenia. Compared with healthy older adults, patients with schizophrenia demonstrated significantly lower teeth numbers, ODK, and calf circumference (CC) (p < .05). Multiple regression analysis revealed that ODK was associated with age and schizophrenia (p < .05). Conversely, tongue pressure was associated with CC (p < .05), suggesting different factors' association with the parameters indicating decreased oral function. Our study findings suggest that older patients with schizophrenia have decreased tongue pressure and generalised muscle mass, highlighting the need to manage oral function. Interventions for tongue pressure were more strongly associated with muscle mass and could be easier to manage than those with disease-dependent changes in ODK. Retrospectively registered.

This study aimed to longitudinally investigate the temporal relationship between tongue pressure and malnutrition in older adults with dysphagia and to determine the antecedent factors. This is a retrospective cohort study. In total, 177 participants aged ≥65 years with dysphagia who visited a specialized dysphagia rehabilitation clinic between 2014 and 2018 were enrolled. Malnutrition was assessed based on the phenotypic criteria (unintentional weight loss, low body mass index, and reduced skeletal muscle mass) from the Global Leadership Initiative on Malnutrition framework. Tongue pressure was measured using a tongue pressure measuring device. The bidirectional association between tongue pressure and malnutrition was examined, adjusting for age, sex, cognitive function, occlusal support status, and comorbidities. In the Cross-Lagged Panel Model, a significant cross-lagged effect was observed from tongue pressure to malnutrition at 6 months (β = -0.135, p < 0.001) and 12 months (β = -0.112, p = 0.028). However, the pathway from malnutrition to tongue pressure was not significant. Logistic regression analysis also revealed that baseline tongue pressure was significantly associated with malnutrition at 6 months (odds ratio [OR] = 0.91, 95% confidence interval [CI]: 0.86-0.95) and 12 months (OR = 0.89, 95% CI: 0.84-0.94). During the follow-up period, tongue pressure improved; however, the prevalence of malnutrition increased. Decreased tongue pressure may precede malnutrition in older adults with dysphagia; however, a reverse relationship was not observed. The findings suggest the importance of incorporating oral function assessment as part of the risk assessment for malnutrition.

BackgroundOral dysfunctions that affect masticatory function, such as tooth loss, reportedly lead to malnutrition, which contributes to cognitive decline and the onset and progression of dementia. Previous studies on oral dysfunction have focused on older people already in need of nursing care. Therefore, we conducted a study of older people able to travel independently or with minor assistance to examine the relationship between oral and cognitive function in memory clinic study participants classified as cognitively normal, with mild cognitive impairment, or with dementia.MethodsParticipants were 178 study participants (median age: 79.0 years, 49.4% female) attending the memory clinic at the National Center for Geriatrics and Gerontology, Japan. Following provision of informed consent, cognitive function was assessed using clinical dementia ratings and oral function assessed using number of present teeth, occlusal force, oral diadochokinesis, repetitive salivary swallowing test, and tongue pressure. The relationships between cognitive and oral function were evaluated using multivariable logistic regression analyses.ResultsOf the participants, 25, 92, and 61 were classified as cognitively normal, with mild cognitive impairment, and with dementia, respectively. Oral diadochokinesis /ka/ was associated with a high risk of mild cognitive impairment: adjusted odds ratio, 6.930 (95% confidence interval: 1.284–37.402, P = 0.024). Repetitive salivary swallowing test score was associated with a high-risk tendency for dementia: adjusted odds ratio, 4.171 (95% confidence interval: 0.981–17.736, P for trend = 0.053). Number of present teeth, occlusal force, and tongue pressure were not associated with mild cognitive impairment or dementia.ConclusionOral diadochokinesis /ka/ was independently associated with mild cognitive impairment. A well-designed cohort study is needed to clarify the causal relationships between cognitive decline and oral diadochokinesis. The ability to identify study participants with possible mild cognitive impairment through regular dental examinations would help to prevent dementia.Trial registrationThis study was registered to UMIN Clinical Trials Registry (UMIN000048126) at 2022–06-21.

The tongue plays an important role in oral functions. Reduced tongue strength is often noted among children with mouth-breathing behaviour. The purposes of this study were to measure the tongue pressure in children with mouth-breathing behaviour, to compare these values to those of children with nasal-breathing behaviour and to analyse the relationship between age and tongue pressure in children with a mouth-breathing pattern and in children with a nasal-breathing pattern. In this cross-sectional analytical observational study, we enroled 40 children aged 5-12years who either exhibited mouth-breathing behaviour (n=20) or nasal-breathing behaviour (gender- and age-matched [±2years] controls; n=20). Tongue pressure was evaluated using the Iowa Oral Performance Instrument; 3 measurements were recorded for each participant, with a 30-seconds rest interval. The average tongue pressure in the mouth-breathing group was lower than that in the nasal-breathing group. There was no difference in tongue pressure between genders. There was a strong and direct correlation between tongue pressure and age in the nasal-breathing group. The breathing pattern impacts tongue pressure development.

ObjectiveOur aim is to determine the strong predictors of the onset of instrumental activities of daily living (IADL) decline in community-dwelling older people.DesignA prospective cohort study with a two-year follow-up.SettingKashiwa City, Chiba Prefecture, Japan and Toshima Ward, Tokyo Metropolitan, Japan.ParticipantsThe data were acquired from two cohorts. The final sample comprised 1,523 community-dwelling older people aged 65–94 years (681 men, 842 women). They were individuals who were independent in IADL at baseline and participated in follow-up IADL assessments two years later.MeasurementsAt baseline, comprehensive assessments were performed including: health interview, gait function, hand-grip strength, skeletal muscle mass, balance function, oral function, dietary lifestyle, cognitive function, quality of life, mental status, and social network. When the two-year follow-up was performed, IADL declines were observed in 53 out of 1,523 people. The association of each Z-transformed parameter with the occurrence of IADL decline was examined by employing a binominal logistic regression model adjusting for age, gender, body weight, body height, and medical history. An odds ratio (OR) and a 95% confidence interval were calculated and compared between different parameters.ResultsA decrease in walking speed and one-legged stance time, whereas an increased timed up & go test time was associated with significant ORs for the occurrence of IADL decline.ConclusionGait-related parameters appear to be the strong predictors of the onset of IADL decline in community-dwelling older people.

ObjectivesUndernutrition is associated with frailty, one of the common reasons for seeking long‐term care. In older adults, nutritional status is known to be associated with oral function; however, it is not yet known if there is a similar association in middle‐aged adults. The present study determined the association between nutritional status and oral function in middle‐aged adults.Material and methodsThis cross‐sectional study was conducted in 117 outpatients aged 40–64 years who underwent dental check‐up at a private dental clinic. Factors associated with oral function, including oral moisture, number of teeth present, oral diadochokinesis, tongue pressure, lip‐seal strength, and masticatory performance, were evaluated. Body mass index (BMI), fat‐free mass index (FFMI), and skeletal muscle mass index (SMI) were analyzed as nutritional statuses. Pearson's correlation analysis was conducted to determine the correlation between nutritional statuses and other variables. Multiple linear regression analysis was performed, with adjustment for age and sex, using BMI, FFMI, or SMI as response variables and oral moisture, maximum tongue pressure, lip‐seal strength, oral diadochokinetic rate, and masticatory performance as explanatory variables.ResultsAll nutritional statuses showed significant correlation with maximum tongue pressure and lip‐seal strength. Multiple linear regression analysis revealed that BMI was associated with maximum tongue pressure and lip‐seal strength, whereas FFMI and SMI showed significant association with sex, maximum tongue pressure, and lip‐seal strength.ConclusionsIn middle‐aged outpatients at a regional dental clinic, lip‐seal strength and tongue pressure were positively associated with BMI, FFMI, and SMI.

The predictive value of tongue pressure for dysphagia in community-dwelling older adults: A cross-sectional study.

BackgroundMotor impairment is a major consequence of spinal cord injury (SCI). Earlier studies have shown that robotic gait orthosis (e.g., Lokomat) can improve an SCI individual’s walking capacity. However, little is known about the differential responses among different individuals with SCI. The present longitudinal study sought to characterize the distinct recovery patterns of gait impairment for SCI subjects receiving Lokomat training, and to identify significant predictors for these patterns.MethodsForty SCI subjects with spastic hypertonia at their ankles were randomly allocated to either control or intervention groups. Subjects in the intervention group participated in twelve 1-hour Lokomat trainings over one month, while control subjects received no interventions. Walking capacity was evaluated in terms of walking speed, functional mobility, and endurance four times, i.e. baseline, 1, 2, and 4 weeks after training, using the 10-Meter-Walking, Timed-Up-and-Go, and 6-Minute-Walking tests. Growth Mixture Modeling, an analytical framework for stratifying subjects based on longitudinal changes, was used to classify subjects, based on their gait impairment recovery patterns, and to identify the effects of Lokomat training on these improvements.ResultsTwo recovery classes (low and high walking capacity) were identified for each clinical evaluation from both the control and intervention groups. Subjects with initial high walking capacity (i.e. shorter Timed-Up-and-Go time, higher 10-Meter-Walking speed and longer 6-Minute-Walking distance) displayed significant improvements in speed and functional mobility (0.033 m/s/week and–0.41 s/week respectively); however no significant change in endurance was observed. Subjects with low walking capacity exhibited no significant improvement. The membership in these two classes—and thus prediction of the subject’s gait improvement trajectory over time—could be determined by the subject’s maximum voluntary torque at the ankle under both plantar-and dorsi-flexion contractions determined prior to any training.ConclusionOur findings demonstrate that subjects responded to Lokomat training non-uniformly, and should potentially be grouped based on their likely recovery patterns using objective criteria. Further, we found that the subject’s ankle torque can predict whether he/she would benefit most from Lokomat training prior to the therapy. These findings are clinically significant as they can help individualize therapeutic programs that maximize patient recovery while minimizing unnecessary efforts and costs.