Biopsychosocial Consideration of Ikigai in Older Adults in Japan through a Cross-Sectional Study.

Ikigai-a Japanese concept that includes elements such as life's purpose and meaning-has been reported to be associated with various systemic health conditions, such as the risk of developing physical dysfunction or death in older adults. However, there are no reports that comprehensively examine the psychological and social aspects of Ikigai. We attempted to clarify the characteristics of Ikigai by examining it from a biopsychosocial model using physical, psychological, and social perspectives through a cross-sectional study on sarcopenia, frailty and healthy life expectancy in a hilly and mountainous area of Japan. Koyadaira in Mima City, which is located in a hilly and mountainous region on Shikoku Island in Japan, was targeted. This cross-sectional study included 105 outpatients aged 65 and over, with an average age of 79.02 ± 6.91 years. Ikigai (self-rating score on a scale of 0 (no Ikigai) to 5 (the highest Ikigai)) participants' level of physical activity (the Physical Activity Scale for the Elderly, PASE), degree of depression (the Geriatric Depression-15 Scale, GDS-15), cognitive function (the Mini-Mental State Examination, MMSE) and social isolation (the abbreviated Lubben Social Network Scale, LSNS-6) was assessed. Significant positive correlations were found between PASE and MMSE. The LSNS-6 significantly correlated with the MMSE and GDS-15. In a path model, out of four paths from PASE, GDS-15, MMSE, and LSNS-6 to Ikigai, the path from the GDS-15 alone was significant (correlation coefficient -0.271, p < 0.01). The adaptability of this model was good. This study indicates that depressive status has a large impact on Ikigai, along with physical, cognitive, and social conditions; thus, it is appropriate to consider that an affective psychological status, such as depressive symptoms, is a fundamental condition for having Ikigai.

[Association between working in small-scale cultivated land as a daily-life task and the physical and cognitive functions among elderly people in hilly and mountainous areas].

AIM: This study aimed to verify whether working in cultivated land as a daily-life task contributes to the maintenance and improvement of physical and cognitive functions. METHODS: The participants were 91 elderly people of ≥65 years of age who owned cultivated land in the mountainous Koyadaira district in Tokushima Prefecture. Sex, age, body mass index (BMI), walking speed as a physical function, and the mini-mental status examination (MMSE) score as a cognitive function were measured and analyzed in addition to the total working hours per week (WH) in cultivated land. RESULTS: The participants were 31 males and 60 females (mean age 78.5±6.6 years). The average values of the evaluated variables were as follows: WH, 18.0±13.2; BMI, 23.4±3.0 kg/m2; walking speed, 0.95±0.28 m/s; and MMSE score, 26.6±3.1 points. In addition, the Mann-Whitney U test and the Chi-square test showed no significant differences between sexes for each item. A logistic regression analysis showed that WH was significantly associated with MMSE (1, ≥28 points; 0, <28 points), and the odds ratio was 1.054 (p=0.010) in the model adjusted for age and BMI, while it was not significantly associated with walking speed (1, ≥1 m/s; 0, <1 m/s). CONCLUSIONS: Working on small-scale cultivated land was significantly associated with the cognitive function but not the physical function. Routine work on small-scale cultivated land as a daily-life task would contribute to the suppression of cognitive decline in older people living in hilly and mountainous areas.

Mouth breathing reduces oral function in adolescence.

Although humans breathe naturally through the nostrils, mouth breathing in children has recently gathered attention. In this study, we hypothesized that tongue function and its related maxillofacial morphology would affect breathing in adolescence. To verify this hypothesis, we examined the association between breathing patterns, including mouth and nasal breathing; oral functions, including tongue motor function; and craniofacial morphology during adolescence, which has not been investigated till date. C3-H, which indicates the anteroposterior position of the hyoid bone in relation to the third cervical vertebra, was significantly smaller in mouth-breathers than in nasal-breathers. Lip-closing force, tongue pressure, and masticatory efficiency were lower in the order of nasal-breathers, oronasal-breathers, and mouth-breathers, and the values for mouth-breathers were significantly lower than those for nasal-breathers. Tongue pressure alone was identified as a significant independent variable, with an odds ratio of 1.063 (95% confidence interval, 1.006-1.123; p < 0.05). Our results indicate a relationship between mouth breathing and the lip-closing force, tongue pressure, and masticatory efficiency, as well as the significance of tongue pressure on mouth breathing in adolescents. The findings highlight the importance of clarifying the pathophysiology of mouth breathing and its underlying causes.

Social frailty as a predictor of all-cause mortality and functional disability: a systematic review and meta-analysis.

The association between social frailty and adverse health outcomes, especially mortality and functional disability, which are essential health outcomes, has not been systematically summarized or meta-analyzed. In this study, we conducted a systematic review and meta-analysis of the impact of social frailty on all-cause mortality and functional disability, while addressing the components of social frailty. In this study, social frailty was operationally defined in alignment with the previous literature, as follows: "a state of increased vulnerability to the interactive back-and-forth of the community, including general resources, social resources, social behaviors, and needs." Hazard ratios or odds ratios described in each selected literature were used as the meta-analytic results. Considering the impact of social frailty on all-cause mortality, the hazard ratio was 1.96 (95% CI 1.20-3.19), indicating a significant association between the two but high heterogeneity. The hazard and odds ratios for the impact of social frailty on functional disability were 1.43 (95% CI 1.20-1.69) and 2.06 (95% CI 1.55-2.74), respectively. A significant association was found between social frailty and functional disability; both hazard and odds ratios were found, and low heterogeneity between these articles was observed. These results highlight the importance of assessing social frailty using more standardized methods and examining its effects on various health outcomes.

Effective use of an extraoral vacuum in preventing the dispersal of particulate matter from metal dental materials.

OBJECTIVES: When dentists adjust prostheses at the dental chairside, particulate matter (PM) from the dental material is dispersed. Little is known about the effective use of an extraoral vacuum (EOV) in preventing PM dispersal. This study aimed to evaluate the effective use of an EOV in preventing the dispersal of metal PM in dental offices. METHODS: The following experimental conditions were planned: the distance from the EOV to the metallic materials (50, 100, 150, and 200 mm), the horizontal angle between the long axis of the micromotor handpiece and EOV (0°, 45°, and 90°), and the operating time of the EOV (during grinding, during grinding and 1 min thereafter, during grinding and the preceding 1 min, 1 min before and after grinding, and during grinding). Carborundum and silicone points were used for grinding and PM dispersal. Diameters (0.3, 0.5, 1.0, and 3.0 µm) were measured using a laser particle counter. RESULTS: Depending on the instrument used to grind, there were undetectable PMs of different diameters (Carborundum point: 0.3 and 0.5 µm, Silicone point: 0.3 µm). PMNs were reduced as the distance from the EOV to metal materials decreased. Operating the EOV before grinding along the long axis of the micromotor handpiece was effective in reducing the PMNs. CONCLUSION: PMNs dispersed when grinding metals were effectively reduced by positioning the EOV closer to the grinding surface (within 150 mm) along the long axis of the micromotor handpiece and operating the EOV before grinding.

Can Measurement of Ultrasonic Echo Intensity Predict Physical Frailty in Older Adults?

Echo intensity (EI) of the tongue in ultrasonography is an easy and quantitative assessment of tongue function. Elucidating the relationship between EI and frailty, is expected to aid in the early detection of frailty and oral hypofunction in older adults. We assessed tongue function and frailty in older outpatients visiting a hospital. The subjects were 101 individuals aged 65 or older (35 men and 66 women, mean age 76.4 ± 7.0 years). Tongue pressure and EI were measured as assessments of tongue function and grip strength, and Kihon Checklist (KCL) scores were measured as assessments of frailty. In women, a significant correlation was not found between the mean EI and grip strength, whereas a significant correlation was noted between each score of the KCL and the mean EI; the scores increased as the mean EI increased. A significant positive correlation was found between tongue pressure and grip strength, but no significant correlation was observed between tongue pressure and the KCL scores. In men, no significant correlation was found between tongue assessments and frailty, except for a significant positive correlation between tongue pressure and grip strength. The results of this study suggest that EI of the tongue is positively associated with physical frailty in women and may be useful for early detection of physical frailty status.

2-methacryloyloxyethyl phosphorylcholine polymer treatment prevents Candida albicans biofilm formation on acrylic resin.

PURPOSE: We aimed to evaluate the effectiveness of photoreactive 2-methacryloyloxyethyl phosphorylcholine (MPC) in inhibiting Candida albicans biofilm formation on polymethyl methacrylate (PMMA) and assess its mechanism and need for re-application by evaluating its interaction with salivary mucin and durability during temperature changes. METHODS: PMMA discs were used as specimens. The MPC coating was applied using the spray and cure technique for the treatment groups, whereas no coating was applied to the control. The MPC treatment (MT) groups were further differentiated based on the number of thermal cycles involved (0, 1000, 2500, and 5000). The optical density was measured to assess mucin adsorption (MA). Contact angle (CA) was calculated to evaluate surface hydrophilicity. The presence of MPC components on the PMMA surface was assessed using X-ray photoelectron spectroscopy (XPS). C. albicans biofilms were evaluated qualitatively (scanning electron microscope images) and quantitatively (colony-forming units (CFUs)). Statistical analysis was conducted using two-way analysis of variance and Tukey's multiple comparison test. RESULTS: MA rate and CA increased significantly in the MT groups, which exhibited significantly fewer CFUs and thinner biofilms than those of the control group. Based on the XPS, MA, and CFU evaluations, the durability and efficacy of the MPC coating were considered stable up to 2500 thermal cycles. Additionally, a significant interaction was observed between mucin concentration and MPC efficacy. CONCLUSIONS: The photoreactive MPC coating, which was resistant to temperature changes for approximately 3 months, effectively prevented C. albicans biofilm formation by modifying surface hydrophilicity and increasing mucin adsorption.

Stress Reduction Effects during Block-Tapping Task of Jaw in Healthy Participants: Functional Near-Infrared Spectroscopy (fNIRS) Measurements of Prefrontal Cortex Activity.

The purpose of this study was to explore the influence of simple jaw opening and closing task of chewing movements on the activities of the prefrontal cortex (PFC) from the viewpoint of stress reduction. We measured cerebral blood flow (CBF) in the PFC during a block-tapping task of the jaw in healthy participants. Eleven young healthy individuals with normal dentition (7 males and 4 females, mean age 28.0 ± 3.7 years) volunteered for this study. CBF was measured using a wearable, functional near-infrared spectroscopy device. Measurements were taken using the central incisors and first molars at interocclusal distances of 5 and 10 mm. The participants were asked to bite a hard/soft block. CBF in all conditions showed limited variability or decreasing trend compared to resting state before the task. The main effect was observed for interocclusal distance (p = 0.008), and there were no significant differences for measurement area of the PFC, tooth type, and material type. An interaction was found between tooth type and material type. In conclusion, these results suggest that simple and rhythmical chewing motion has an effect of reducing CBF in the PFC and resting the PFC, which is an especially notable aspect of periodontal sensory information in the molar.

Novel Magnetic Attachment System Manufactured Using High-Frequency Heat Treatment and Stamp Technique: Introduction and Basic Performance.

Recently, a novel magnetic attachment with extremely low cost and high performance was developed. This article aims to introduce a novel magnetic attachment and to evaluate its basic eligibility for denture retention in clinical practice. The novel magnetic attachment system used in this study was the direct-bonding root-keeper-type Magteeth™ MT800 (MagneDesign, Nagoya, Japan). The retentive force without displacement (position 0) and after horizontal displacement to positions 0.5, 1, 1.5, 2, 2.5, and 3 mm were measured. The values relative to the retentive force without displacement were gradually decreased to 82.7 ± 16.3%, 68.8 ± 17.1%, 62.4 ± 15%, 47.2 ± 13.1%, 35.7 ± 9.9%, and 20.7 ± 6.5%, respectively. The retentive force and magnetic field strength did not change significantly after the load test (100 N load, 10,000 times). No new gap between the metal and resin was found in the root keeper- and magnet assembly-embedded blocks after the load test. Some scratches on magnetic assembly and root keeper surface, while no change in the resin texture after the load test were observed. Based on the findings of this preliminary study, this novel low-cost magnetic attachment exhibited favorable retention, strength, and durability for clinical use.

Application of artificial intelligence in the dental field: A literature review.

PURPOSE: The purpose of this study was to comprehensively review the literature regarding the application of artificial intelligence (AI) in the dental field, focusing on the evaluation criteria and architecture types. STUDY SELECTION: Electronic databases (PubMed, Cochrane Library, Scopus) were searched. Full-text articles describing the clinical application of AI for the detection, diagnosis, and treatment of lesions and the AI method/architecture were included. RESULTS: The primary search presented 422 studies from 1996 to 2019, and 58 studies were finally selected. Regarding the year of publication, the oldest study, which was reported in 1996, focused on "oral and maxillofacial surgery." Machine-learning architectures were employed in the selected studies, while approximately half of them (29/58) employed neural networks. Regarding the evaluation criteria, eight studies compared the results obtained by AI with the diagnoses formulated by dentists, while several studies compared two or more architectures in terms of performance. The following parameters were employed for evaluating the AI performance: accuracy, sensitivity, specificity, mean absolute error, root mean squared error, and area under the receiver operating characteristic curve. CONCLUSION: Application of AI in the dental field has progressed; however, the criteria for evaluating the efficacy of AI have not been clarified. It is necessary to obtain better quality data for machine learning to achieve the effective diagnosis of lesions and suitable treatment planning.