Factors associated with the oral health status of patients with schizophrenia: A cross-sectional study.

BACKGROUND: 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. OBJECTIVE: We surveyed patients with schizophrenia to identify factors associated with ageing-related variations in oral function. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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. TRIAL REGISTRATION: Retrospectively registered.

Impact of oral health management by nurses and dental professionals on oral health status in inpatients eligible for the Nutrition Support Team: A longitudinal study.

OBJECTIVE: As the participation of dental professionals in multidisciplinary care is often limited, instructions on oral health management provided by dental professionals to other professionals are important to achieve transdisciplinary oral health management; however, the effectiveness of such instructions remains unclear. In this longitudinal study, we aimed to determine the impact of oral health management provided by dental professionals and nurses instructed on oral health management by dental professionals on the oral health of inpatients eligible for a Nurition Support Team (NST). METHODS: The study participants were 117 patients (66 men and 51 women, mean age: 71.9 ± 12.5 years) who received oral health management during the NST intervention period. The participants received oral health management from nurses (Ns group) or dental professionals (D group). The nurses who conducted the oral health management received instructions from dental professionals. Oral health was assessed at the beginning and end of the NST intervention using the Oral Health Assessment Tool (OHAT). RESULT: The Ns and D groups showed significant improvements in the total OHAT scores at the end of the NST intervention. Both groups showed significant improvements in the OHAT subitems of lip, tongue, gums and tissues, saliva, oral cleanliness and dental pain, while only the D group showed a significant improvement in the denture subitem. CONCLUSION: Effective oral health management provided by dental professionals or by nurses trained by them improved the oral health status of inpatients eligible for NST at an acute-care hospital.

Association between oral health status and functional independence measure on admission in convalescent hospitalized patients.

BACKGROUND: Oral health management has become increasingly important for acute inpatients. Older patients often require extended periods of medical care, and oral health management is necessary in the convalescent period following the acute period. During the convalescent period, oral health management remains unclear as convalescent hospitals have limited dental resources, and effective dental care must be provided if the objective of hospitalization is to improve life functions. This study aimed to clarify the relationship between daily functioning and oral health status at the time of admission to a convalescent hospital to aid in improving daily functioning in the convalescent period. METHODS: We included patients admitted to the rehabilitation department of a specific convalescent hospital from January to December 2021. A total of 375 patients were included in the study, with complete data records. At admission, we gathered information from the medical records, including the patient's age, sex, primary disease, Charlson Comorbidity Index, Mini Nutritional Assessment Short-Form (MNA-SF), Functional Oral Intake Scale (FOIS), Functional Independence Measure (FIM), number of teeth, and Oral Health Assessment Tool (OHAT). Statistical analysis was conducted using SPSS Ver. 27, with a significance level of 5%. RESULTS: The mean age of the 375 participants (189 men and 186 women) was 75.0 ± 12.1 years (range, 42-97 years), and over 80% were > 65 years. About 30% of major diseases could be attributed to strokes and fractures, followed by spinal cord and spine diseases. In non-stroke patients, multiple regression analysis using FIM motor, FIM cognitive, and FIM and OHAT total scores as objective variables showed that higher total scores of MNA-SF, FOIS, and lower modified Rankin Scale and OHAT were significantly associated with better FIMs. Lower OHAT scores were significantly associated with lower FOIS and MNA-SF scores, male sex, having fewer teeth, and poor dietary patterns. CONCLUSIONS: The convalescent period is an opportune time to provide intensive dental care due to the generally stable condition and extended hospital stay. Our results suggest that oral health management, such as dysphagia rehabilitation and denture treatment, is important for maintaining and improving independence, a key objective of convalescent rehabilitation, and malnutrition improvement.

Factors influencing the selection of oral healthcare providers in multidisciplinary Nutrition Support Team for malnourished inpatients: A cross-sectional study.

BACKGROUND: Oral health management involving dental professionals in a multidisciplinary Nutritional Support Team (NST) is effective collaborative care. However, the indicators for the triage of oral health management requirements and selection of oral healthcare providers remain unclear. OBJECTIVE: This cross-sectional study included inpatients with malnutrition and aimed to investigate the factors associated with determining the need for oral health management involving dental professionals and selecting primary oral healthcare providers when needed. METHODS: Participants included 255 inpatients (154 males and 101 females, mean age 69.7 ± 14.4 years) aged ≥20 years who underwent oral assessment by the NST between April 2016 and July 2019. Participants were assigned to the following groups: good oral health group, oral health management by nurses under the supervision of dental professionals group, and oral health management by dental professionals group. The comprehensive oral health status was investigated using the Oral Health Assessment Tool (OHAT). The total OHAT score ranges from 0 to 16, with a higher score indicating a poorer oral environment. RESULTS: The total OHAT score had a significant correlation with the need for oral health management by dental professionals. Inpatients with denture problems required oral health management from dental professionals. The optimal cutoff value of the total OHAT score for determining the need for oral health management was four. CONCLUSION: The need for oral health management by dental professionals increased with worsening oral health status, especially denture problems. The OHAT score could be used to triage inpatients who require oral health management collaborated with dental professionals.

Effect of the denture adhesive for dry mouth on the retentive force of the experimental palatal plates: a pilot controlled clinical trial.

BACKGROUND: A denture adhesive for dry mouth with good cleaning properties has recently been developed. While previous studies on models have shown the effectiveness of denture adhesives in terms of retention and cleanability, no reports have evaluated their effectiveness in the oral cavity. The aim of this study was to compare and investigate the retention and usability of an experimental palatal plate in the dentulous jaw using a denture adhesive for dry mouth, a conventional cream-type denture adhesive, an oral moisturizer, and a denture moisturizer. METHODS: Ten healthy dentulous participants (mean age 27.2 ± 1.6 years) were included in the study. Palatal plates were fabricated. Four test samples were used: denture adhesive for dry mouth, conventional denture adhesive (cream type), oral moisturizer, and denture moisturizer. The sample was applied to the inner surface of the palatal plates, and the retentive force of the palatal plate was measured every 10 min for 30 min. After the measurements, the study participants were asked to rinse the palatal plate with water and subjectively evaluate the samples used. RESULTS: The conventional denture adhesive (cream type) showed increased retentive force over time, with the maximum retentive force obtained after 10 min of application. However, its washability was rated second lowest. The denture adhesive for dry mouth showed the highest retentive force immediately after application. Its washability was also good. CONCLUSIONS: The results suggest that the denture adhesive for dry mouth has reasonable retentive force in the oral cavity and cleaning properties compared to the conventional cream-type denture adhesive.

Association between oral health and advisability of oral feeding in advanced cancer patients receiving palliative care: a cross-sectional study.

PURPOSE: Maintenance of oral feeding is important in terms of maintaining and improving the quality of life in terminal cancer patients receiving palliative care. Although adequate oral health status is essential for oral feeding in hospitalized patients, the relationship between oral health and oral feeding in patients receiving palliative care remains unclear. This cross-sectional study aimed to examine how the general condition and oral health status of these patients relate to decisions regarding their nutritional intake methods. METHODS: This retrospective cross-sectional study included 103 terminal cancer patients (59 men and 44 women; mean age, 73.8 ± 10.9 years) who received palliative care between April 2017 and August 2019. The nutritional method was assessed using the Functional Oral Intake Scale (FOIS). We assessed two types of nutritional methods: (1) the method advised by the attending physician until the initial dental examination (FOIS-I) and (2) the recommended method based on consultation with a palliative care doctor and dentist after the initial oral examination (FOIS-R). Furthermore, the participants' basic information and Dysphagia Severity Scale (DSS) and Oral Health Assessment Tool (OHAT) scores were assessed. RESULTS: There was a divergence between FOIS-I and FOIS-R. FOIS-R was significantly higher than FOIS-I (p < 0.001). Multiple regression analysis revealed that the time until death, DSS score, and OHAT score had a significant impact on determining the food form for oral feeding. CONCLUSIONS: Appropriate oral health assessment is important in determining the food form and indication for oral feeding among patients receiving palliative care.

Factors affecting the oral health of inpatients with advanced cancer in palliative care.

PURPOSE: Patients with terminal cancer undergoing multidisciplinary palliative care often have oral health problems, but these details are still unclear. This cross-sectional study aimed to elucidate the oral health of patients with terminal-stage cancer who are inpatient recipients of acute-phase palliative care, and to unveil the factors affecting their oral health. METHODS: Participants were 121 patients with terminal-stage cancer (68 males, 53 females, mean age: 73.6 ± 11.1 years) and oral health complaints. They received palliative care at Tokyo Medical and Dental University Medical Hospital between April 2017 and August 2019. Their demographic and medical details were extracted, retrospectively, from their medical records, and their oral health status, such as the number of natural teeth, removable denture usage, Oral Health Assessment Tool (OHAT), and Dysphagia Severity Scale, were evaluated. All outcomes were assessed by a dentist from the palliative care team. RESULTS: The problems with soft tissue, saliva, and oral cleanliness were observed. The absence of posterior occlusal support was common, and the use of removable dentures was often inadequate. In contrast, swallowing function was relatively well-conserved and 46.3% of the participants were capable of nutrition intake solely by mouth. Multiple regression analysis revealed a significant association between total OHAT score and age, consciousness level, prognostic level, and method of nutritional intake. CONCLUSION: The results revealed that the oral health of terminal cancer patients under palliative care declined despite receiving routine oral care from nurses, and suggest the importance of including dental professionals in multidisciplinary palliative care.

Effect of an Oral Frailty Measures Program on Community-Dwelling Elderly People: A Cluster-Randomized Controlled Trial.

INTRODUCTION: Oral frailty describes a trivial decline in the oral function and is considered to be related to frailty. Thus, effective management of oral frailty could prevent or ameliorate physical frailty and the need for care. However, there is a lack of consensus regarding specific interventions for oral frailty. In this cluster-randomized controlled trial, we investigated the effects of a newly developed oral frailty measures program mentored by dentists and dental hygienists for elderly people in a clinical setting. METHODS: Of 3,296 participants included in a field survey, 219 who regularly visited dental clinics and met at least 3 of the following 6 criteria for oral frailty were considered eligible: <20 natural teeth, decreased chewing ability, decreased articulatory oral-motor skills, decreased tongue pressure, and substantial subjective difficulties in eating and swallowing. After applying the inclusion and exclusion criteria, we studied 51 patients in the intervention group (14 men and 37 women; mean age, 78.6 years) and 32 patients in the control group (7 men and 25 women; mean age, 78.0 years). We implemented a 12-week oral frailty measures program only for the intervention group. The program included preparatory oral exercises, mouth-opening training, tongue pressure training, prosodic training, and masticatory training. Primary outcome measures were the chewing ability score, articulatory oral motor skill for /ta/, tongue pressure, subjective difficulty in eating tough foods, and subjective difficulty in swallowing. We compared baseline characteristics using the Mann-Whitney U and χ2 tests for continuous and categorical variables, respectively. A repeated-measures two-way ANOVA was used to determine the efficacy of independent intervention variables, following the Wilcoxon signed-rank test. The groups (intervention/control) and time (baseline/week 12) were the independent variables. Oral frailty measures were the dependent variables. RESULTS: Baseline characteristics and assessment results were similar between groups. We observed significant improvements in the intervention group in terms of articulatory oral motor skill for /ta/ and tongue pressure (p < 0.001). No improvements were observed in the control group. DISCUSSION/CONCLUSION: Our results suggest that our oral frailty measures program effectively alleviates oral frailty. Future studies are needed to clarify the impact on preventing physical frailty and improving the nutritional status.

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.

Impact of oral health guidance on the tongue-lip motor function of outpatients at a dental hospital.

OBJECTIVE: To clarify the effect of oral health guidance on tongue-lip motor function in the outpatients visiting the Showa University Dental Hospital (Tokyo, Japan). BACKGROUND: The management of the oral function of older people visiting a dental hospital is important. Previous studies have revealed that tongue-lip motor function is easy to improve. However, the impact of oral health guidance on tongue-lip motor function in the outpatients of dental hospital requires further elucidation. MATERIALS AND METHODS: The participants (n = 35) included patients who were diagnosed with low tongue-lip motor function on evaluation by oral diadochokinesis (ODK) at the outpatient clinic. They underwent a second examination approximately 6-12 months later. Their demographic characteristics were recorded. Oral health guidance was provided through an educational leaflet on oral hypofunction when the participants visited the clinic. It included content on tongue twisters, voice training and a range of movement and muscle training of the tongue and lip. RESULTS: Following oral health guidance on tongue-lip motor function, the ODK values changed from 5.6 at the first examination to 6.0 at the second for /pa/, from 5.6 to 5.8 for /ta/ and from 5.2 to 5.4 for /ka/. This improvement was not significantly associated with age, sex, measurement period or number of visits. CONCLUSION: The findings of this longitudinal study suggested that oral health guidance using an oral hypofunction educational leaflet may be effective in improving the tongue-lip motor function of outpatients who had low tongue-lip motor function, regardless of the measurement period or the number of visits to the dental hospital.

Oral health status and its association with nutritional support in malnourished patients hospitalised in acute care.

OBJECTIVES: This cross-sectional study aimed to examine the oral health of malnourished acute-care hospital inpatients, who were the subjects of a nutritional support team (NST). We also aimed to elucidate the systemic and nutritional factors associated with the oral health of those patients. BACKGROUND: Interventions by NST are essential for inpatient nutrition management and require the active participation of dental professionals. However, information is limited regarding the state of oral health among acute-stage malnourished inpatients. MATERIALS AND METHODS: We enrolled 255 hospitalised patients (101 women, mean age: 69.7 ± 14.4 years) who were referred to an NST for nutrition management between April 2016 and July 2019. The main outcome was the Oral Health Assessment Tool (OHAT) scores. Moreover, we assessed participants' demographic characteristics, nutritional status, number of natural and functional teeth, posterior occlusal support, denture use, Dysphagia Severity Scale, whether oral health management was needed, and the methods of nutrition intake. RESULTS: Several participants presented with a deteriorated oral health. Consequently, oral health management was often regarded necessary in these patients. Approximately half were fed by parenteral or tube feeding. Multiple regression analysis revealed the OHAT score has a positive association with age (P = .008), and a negative association with body mass index (P = .009) and the method of nutrition intake (P = .028). CONCLUSION: Malnourished inpatients at an acute care hospital who were subject to an NST had a deteriorated oral health status. Additionally, poor oral health was associated with poor nutritional status and nutrition intake methods.

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.

Effect of traction direction and pressure load on the palatal plate on retentive force.

BACKGROUND: Recently, a denture adhesive that is easy to clean and contain moisturizing ingredients have been developed for patients with dry mouth. Although the retentive force produced by conventional denture adhesives and oral moisturizers have been compared on models, no study has reported their comparison in the oral cavity. In this study, we aimed to clarify the effects of different directions of traction and loads at the time of pressure contact on the retentive force on a palatal plate made from a dentulous jaw model. METHODS: A palatal plate was fabricated with thermoplastic resin on a dentulous jaw model, and a loop-shaped traction device was attached to the centre of the palate. The test samples were a cream-type denture adhesive, a denture adhesive for dry mouth, an oral moisturizer, and a denture moisturizer. The specimens were applied to the inner surface of the plate, which was then mounted under vertical pressure. Then, the retentive force was measured, using a digital force gauge, while the plate was pulled in different directions and with different loads. RESULTS: No significant difference in retentive force was observed in any of the test samples when the direction of traction was between 45° and 60°. The retentive force of the denture adhesive for dry mouth was significantly higher with a direction of traction of 90° than that of 45° or 60°. The retentive force when oral moisturizer was used was significantly higher in the 90° traction direction than in the 45° direction. There was no significant difference between a force of 4.0 kgf or 5.5 kgf when using a denture adhesive for dry mouth. Comparing the four load size conditions, the larger the load, the higher was the retentive force. Similar results were obtained for the cream-type denture adhesive and denture moisturizer. Significantly higher retentive force was observed for larger loads when oral moisturizer was used. CONCLUSIONS: The results suggest that the direction of traction and the pressure load affect the retentive force on a palatal plate.

Comparison of oral hypofunction tests and determination of reference values for a subjective masticatory function test.

BACKGROUND: In Japan, oral hypofunction has been recognized as a disease since 2018. An alternative to occlusal force testing for assessing oral hypofunction is the evaluation of the number of natural teeth. Subjective masticatory function testing, which evaluates the ease or difficulty in chewing foods, is an effective alternative to occlusal force testing. However, no reference values have been established for this test. We determined the reference values of the subjective masticatory function test and evaluated its potential as a substitute for the number of natural teeth for assessing oral hypofunction. METHODS: The sample consisted of 184 older adults who visited the Department of Geriatric Dentistry, Showa University Dental Hospital, from July 2018 to January 2020. The subjective masticatory function test (table for evaluation of chewing function in complete denture wearers [Chewing Score 20]) was performed using 20 foods. The occlusal force test and a receiver operating characteristic curve were used to determine the reference values for Chewing Score 20. The sensitivity, specificity, and positive and negative predictive values were calculated and compared with the occlusal force test and the number of natural teeth. RESULTS: A significant correlation (r) was found between the occlusal force test and the Chewing Score 20 (r = 0.526, p < 0.001). The reference value for Chewing Score 20 was < 85. Although the Chewing Score 20 was less sensitive than the number of natural teeth, it demonstrated a higher specificity and a positive predictive value. CONCLUSION: Herein, a score of < 85 on the subjective masticatory function test was determined to be the optimal quantitative reference. The subjective masticatory function test may be used as an alternative for assessing oral hypofunction.

Development of an optimal relief method for the palatal plate by stress analysis.

BACKGROUND: Plate dentures cannot be easily modified after fabrication; therefore, the sites and magnitude of relief must be effectively assessed at the time of fabrication. However, a considerable variation exists in the magnitude of optimal relief and relief range, and there are no guidelines that present these clearly, leading the dentists to decide subjectively. Thus, this study aims to develop an optimal relief method to improve the stress bearing capacity of the palatal mucosa. METHODS: The objective of this study, namely, the borderline, was set in steps. A three-dimensional finite element model for the pseudopalatal plate was created and used to evaluate the changes in stress distribution in the palatal mucosa due to the selective relief of stresses above the borderline. The resulting data were used to develop the optimal relief method. RESULTS: In the relief model with a borderline of 0.04 MPa or higher, the distribution volume at which a high stress of 0.20 MPa or higher is generated was approximately 800% of that with the no-relief model, and in the relief model with a borderline of 0.06 MPa or higher, the respective ratio was approximately 280%. On the other hand, the relief models with a borderline of 0.14 MPa or higher were approximately 60%. In the mid-palatal relief model, the distribution volume at which a stress of 0.20 MPa or higher was generated was 180% of that in the relief model. CONCLUSIONS: The supportive strength of plates can be increased by selectively applying optimal relief rather than standard relief, allowing for easier and more effective plate-denture treatment.

Changes in denture retention with denture adhesives and oral moisturizers for the oral cavity: an in vitro study.

BACKGROUND: It is difficult to maintain complete dentures during meals in place. This in vitro study aimed to assess changes in denture retention between rest and function using denture adhesives and oral moisturizers in an oral cavity model. METHODS: The following test samples were applied between the palatal plate and the edentulous jaw ridge model: denture adhesive, denture adhesive for dry mouth, oral moisturizer, and denture moisturizer. The retentive force was measured under two conditions: at rest while immersed in water and during function with a 2.5-kg load applied. The plate was pulled perpendicular to the occlusal plane and the retentive force was measured using a digital force gauge. RESULTS: Under dry conditions, denture adhesive for dry mouth and oral moisturizer had a significantly higher retentive force than denture adhesive and denture moisturizer. After 30 min of immersion in water, the retentive force of the denture adhesive increased while that of the oral moisturizer decreased. After 30 min of function, the retentive force of the denture adhesive and denture adhesive for dry mouth remained high, while that of the oral moisturizer and denture moisturizer significantly decreased. Between rest and function, the retentive force of the denture adhesive and denture adhesive for dry mouth was high, and that of the oral moisturizer was low. CONCLUSIONS: Immediately after use, denture adhesive for dry mouth exhibited high retentive force, but retention gradually decreased due to its water content.

Experimental study on the factors affecting torque of beam-type implant torque wrenches.

BACKGROUND: Screw breakage and loosening are the most common mechanical complications associated with implant treatment, and they may occur due to excess or inadequate screw tightening torque. When fastening and fixing the implant superstructure, screws are tightened using a torque wrench, which is essential for an accurate tightening force. However, the characteristics of the torque wrench have not been fully verified. Therefore, we aimed to clarify the factors affecting the torque with a focus on beam-type torque wrenches, which are the main types of wrenches. METHODS: The torque values generated by beam-type torque wrenches from eight manufacturers were measured using a torque gauge. To investigate the influence of the location of the beam relative to the scale, measurements were performed with a scale aligned with the trailing edge, center, and leading edge of the beam respectively. Additionally, measurements were taken at 90°, 60°, and 30° to examine the effect of the angle at which the examiner read the torque value. Under each condition, a single examiner applied the recommended torque to each manufacturer's screws five times in a clockwise direction. The average measured torque, standard deviation, bias, and coefficient of variation were calculated and compared accordingly. RESULTS: Wrenches from six manufacturers demonstrated excellent accuracy for measurements at the center of the beam (bias within ± 4%). For measurements at 90°, equipments from five manufacturers displayed excellent accuracy (bias within ± 7%), and seven showed excellent repeatability (coefficient of variation ≤ 2%). CONCLUSION: The scale should be aligned with the center of the beam and read from 90° while using a torque wrench. The accuracy and repeatability torques generated by the wrenches differed according to the manufacturer, scale width, scale line width, beam width, and distance between the scale and beam center. Based on these results, we suggest that a torque wrench must be selected after determining the difference in the structure of the torque wrench.

Patients with mild cognitive impairment diagnosed at dementia clinic display decreased maximum occlusal force: a cross-sectional study.

BACKGROUND: Previous research indicates that patients with mild cognitive impairment (MCI) are more likely to have poor oral health and impairments in oral functions, which may be due to few remaining teeth and impaired tongue and lip motor function. However, the oral health of those patients following comprehensive cognitive assessment by a dementia specialist has not been sufficiently investigated. Therefore, this study aimed to clarify the oral function of patients with MCI and the association between oral health and lower cognitive function. METHODS: This cross-sectional study included 96 participants (men: 35; women: 61; mean age: 73.3 ± 8.5 years) who visited a dementia clinic between December 2017 and January 2020. Participants' cognitive function was assessed by a dementia specialist using neuropsychological and hematological tests and neuroimaging immediately after enrollment. The participants were divided into the healthy and MCI groups according to comprehensive cognitive assessment. Participants' age, sex, body mass index, primary disease, education level, drinking habits, smoking habits, living environment, employment status, and exercise habits were evaluated. Moreover, oral outcomes, including the number of existing teeth, number of functional teeth (natural and prosthetic teeth which were occluded with antagonists), denture use, oral dryness, tongue and lip motor function, tongue pressure, occlusal force, masticatory ability, and swallowing ability were recorded. The Mann-Whitney U test, χ2, and Fisher's exact tests were used for between-group comparisons. Furthermore, logistic regression analysis using MCI diagnosis as the target variable was performed. RESULTS: A comprehensive evaluation of the cognitive function of the study participants by the dementia specialist revealed that 48 participants (mean age: 69.8 ± 8.8 years) were healthy and 48 (mean age: 76.9 ± 6.7 years) had MCI. MCI participants were significantly older (p < 0.001) and had significantly fewer existing teeth (p = 0.031) and lower maximum occlusal force (p = 0.019) than healthy participants. Age (odds ratio: 1.126, p = 0.002) and maximum occlusal force (odds ratio: 0.978, p = 0.048) were significantly associated with lower cognitive function. CONCLUSIONS: Patients with MCI had poorer oral health than healthy individuals. Decreased maximum occlusal force was independently associated with lower cognitive function, even when adjusted for age and sex.

Relationship between tongue pressure and back muscle strength in healthy elderly individuals.

BACKGROUND: Aging is associated with a decrease in muscle mass and strength in swallowing muscles, as well as in whole-body muscles. A decrease in tongue pressure (TP) is related with whole-body function, and the trunk, including abdominal and back muscles, forms the core of the body. However, the direct relationship between TP and trunk muscle strength remains unclear. AIMS: To clarify the association between back muscle strength, an indicator of trunk muscle strength, and TP in healthy elderly individuals. METHODS: In all, 112 healthy community-dwelling individuals aged ≥ 60 years (men: 35, median age 74.0; women: 77, median age 69.0) were included. Body mass index (BMI), TP, and back muscle strength (BMS) were measured. Tooth loss pattern was evaluated by the Eichner classification. Participants were divided into two groups based on the median of the BMS and classified into three groups based on the Eichner index (Eichner A, B, and C). The effects of BMS and occlusal support on TP were analyzed. RESULTS: In the low BMS group, there was a significant difference in TP between the Eichner B and Eichner C (p = 0.017) groups. However, in the high BMS group, occlusal support did not affect TP. Moreover, the explanatory factors for TP were BMS (ß = 0.373, p = 0.001) and the Eichner index (ß = 0.190, p = 0.036). CONCLUSIONS: TP was correlated more with BMS than aging and occlusal support in healthy elderly individuals. This study indicated that the clinical evaluation of the whole body is important when assessing oral and swallowing function.

Association of aging and tooth loss with masseter muscle characteristics: an ultrasonographic study.

OBJECTIVES: This study aimed to investigate the relationship between aging and tooth loss on masseter muscle quantity and quality. MATERIALS AND METHODS: This cross-sectional study was conducted among 112 participants (in their 20s to 90s) who were independent in activities of daily living and were able to follow verbal commands. Exclusion criteria comprised participants with a lack of molar occlusal support, diseases that could affect muscle function, or temporomandibular disorder. Age, tooth loss, and weight were documented, and masseter muscle thickness (MMT) and masseter muscle echo intensity (MMEI) were measured using an ultrasonic diagnostic apparatus. A multiple regression analysis was used to determine the relationship between MMT, MMEI, aging, and tooth loss, among each sex. The significance level in the statistical analysis was p < 0.05. RESULTS: In males, aging was a significant explanatory variable for MMT (adjusted R2 = 0.27), while both aging and weight were significantly associated with MMEI (adjusted R2 = 0.54). In females, tooth loss and aging were significant explanatory variables for MMT (adjusted R2 = 0.36) and MMEI (adjusted R2 = 0.5), respectively. In both men and women, MMT and MMEI were highly correlated. CONCLUSIONS: Masseter muscles in males were more likely to be attenuated by aging than in females. The main attenuation factors were observed to differ between MMT and MMEI in women. CLINICAL RELEVANCE: In females, preservation of the natural dentition or prosthetic treatment may be effective for maintaining masseter muscle characteristics. In males, additional approaches, such as resistance exercise training, may be necessary.