Development of Korean Representative Headforms for the Total Inward Leakage Testing on Filtering Facepiece Respirators.

Background: The lack of headforms that accurately reflect the head characteristics of Koreans and the demographic composition of the Korean population can lead to inadequate FFR testing and reduced effectiveness of FFRs. Method: Direct measurements of 5,110 individuals and 3D measurements of 2,044 individuals, aged between 9 and 69 years, were sampled from the data pool of Size Korea surveys based on the age and gender ratios of the Korean resident demographics. Seven head dimensions were selected based on the ISO 16976-2, availability of Size Korea measurements, and their relevance to the fit performance of FFRs. A principal component analysis (PCA) was performed using the direct measurements to extract the main factors explaining the head characteristics and then the main factors were standardized and remapped to 3D measurements, creating five size categories representing Korean head shapes. Lastly, representative 3D headforms were constructed by averaging five head shapes for each size category. Results: The study identified two main factors explaining Korean head characteristics by the PCA procedure specified in ISO 16976-2 and developed five representative headforms reflecting the anthropometric features of Korean heads: medium, small, large, short & wide, and long & narrow. Conclusion: This study developed representative headforms tailored to the Korean population for conducting total inward leakage (TIL) tests on filtering facepiece respirators (FFRs). The representative headforms can be used for TIL testing by employing robotic headforms to enhance the performance of FFRs for the Korean target population.

Development of a novel in vitro model for non-cavitated carious lesion formation reflecting carious lesion activity.

BACKGROUND: Oral biofilms are a critical component in dental caries formation. However, current remineralization studies often overlook the impact of microbial factors. Therefore, a comprehensive clinically relevant assessment of caries is needed. This study aimed to develop a novel in vitro model capable of generating non-cavitated carious lesions that incorporates both mineral loss and microbial activity using quantitative light-induced fluorescence-digital (QLF-D) technology. METHODS: A total of 44 artificial early carious lesions were formed using bovine incisors. The extent of fluorescence loss (ΔF) was analyzed using a QLF-D camera. Oral microcosm biofilms were then employed to construct 22 active and 22 inactive carious lesions. The red fluorescence emission rate (ΔR) and bacterial viability (RatioG/G+R) was measured using QLF-D camera and a live-dead bacterial assay, respectively. Independent t-tests were performed to compare ΔF, ΔR, and bacterial viability of artificial carious lesions according to their activity status. RESULTS: No significant difference in ΔF between the lesions was found based on activity status (p = 0.361). However, the ΔR of active lesions was 1.82 times higher than that of inactive lesions, and the RatioG/G+R was 1.49 times higher in active lesions than in inactive lesions (both p < 0.001). CONCLUSIONS: The significant differences observed in ΔR and RatioG/G+R between active and inactive lesions emphasize the importance of considering lesion activity status when evaluating the potential efficacy of remineralization agents. This study presents a novel in vitro remineralization assessment model that reflects carious lesion activity while controlling baseline mineral distributions of lesions.

Effect of resuscitative endovascular balloon occlusion of the aorta in nontraumatic out-of-hospital cardiac arrest: a multinational, multicenter, randomized, controlled trial.

BACKGROUND: Out-of-hospital cardiac arrest (OHCA) is a significant public health issue worldwide and is associated with low survival rates and poor neurological outcomes. The generation of optimal coronary perfusion pressure (CPP) via high-quality chest compressions is a key factor in enhancing survival rates. However, it is often challenging to provide adequate CPP in real-world cardiopulmonary resuscitation (CPR) scenarios. Based on animal studies and human trials on improving CPP in patients with nontraumatic OHCA, resuscitative endovascular balloon occlusion of the aorta (REBOA) is a promising technique in these cases. This study aims to investigate the benefits of REBOA adjunct to CPR compared with conventional CPR for the clinical management of nontraumatic OHCA. METHODS: This is a parallel-group, randomized, controlled, multinational trial that will be conducted at two urban academic tertiary hospitals in Korea and Taiwan. Patients aged 20-80 years presenting with witnessed OHCA will be enrolled in this study. Eligible participants must fulfill the inclusion criteria, and written informed consent should be collected from their legal representatives. Patients will be randomly assigned to the intervention (REBOA-CPR) or control (conventional CPR) group. The intervention group will receive REBOA and standard advanced cardiovascular life support (ACLS). Meanwhile, the control group will receive ACLS based on the 2020 American Heart Association guidelines. The primary outcome is the return of spontaneous circulation (ROSC). The secondary outcomes include sustained ROSC, survival to admission, survival to discharge, neurological outcome, and hemodynamic changes. DISCUSSION: Our upcoming trial can provide essential evidence regarding the efficacy of REBOA, a mechanical method for enhancing CPP, in OHCA resuscitation. Our study aims to determine whether REBOA can improve treatment strategies for patients with nontraumatic OHCA based on clinical outcomes, thereby potentially providing valuable insights and guiding further advancements in this critical public health area. TRIAL REGISTRATION: ClinicalTrials.gov NCT06031623. Registered on September 9, 2023.

Oral Health-Related Factors Associated with Dysphagia Risk among Older, Healthy, Community-Dwelling Korean Adults: A Pilot Study.

Most previous studies addressing dysphagia examined individuals who already had diseases causing dysphagia and did not pay much attention to oral health conditions as a risk factor. This pilot study investigated 62 healthy adults aged 65 years or older who were living independently in the community, performed basic activities of daily living independently, and had no history of a causative disease of dysphagia to identify the factors associated with dysphagia risk, especially oral health. The Dysphagia Risk Assessment Scale was used to screen the patients for dysphagia. Hyposalivation was diagnosed by evaluating the unstimulated salivary flow rate, and orofacial muscle strength (anterior tongue elevation, buccinator muscle, and lip strength) was quantitatively measured using the Iowa Oral Performance Instrument. To analyze the factors associated with dysphagia risk, the Mann-Whitney test, Kruskal-Wallis test, and multiple logistic regression analyses were conducted. In the final regression model adjusted for sociodemographic characteristics, the oral health-related factors independently associated with dysphagia risk were buccinator muscle strength, hyposalivation, and subjective masticatory discomfort (p < 0.05). Therefore, our findings suggest that weak buccinator muscle strength, hyposalivation, and subjective masticatory discomfort are valuable indicators for the early detection of dysphagia in older, healthy, independent, community-dwelling adults.

Red fluorescence intensity as a criterion for assessing remineralization efficacy in early carious lesions.

OBJECTIVES: Evaluating early carious lesion activity with an objective and clinically valid approach is crucial for developing effective treatment plans. Therefore, we here assessed the activity of non-cavitated carious lesions using a quantitative light-induced fluorescence-digital (QLF-D) camera and compared the remineralization efficiency after fluoride treatment according to the lesion's activity level. METHODS: Red fluorescence emission rate (ΔR) and fluorescence loss (ΔF) were evaluated in 44 non-cavitated carious lesions by using a QLF-D camera. Based on the ΔR level, the lesions were classified into 22 active (ΔR ≥37.55) and 22 inactive carious lesions (ΔR <37.55). Each lesion was treated with 1.23 % fluoride gel for 60 s and then immersed into artificial saliva for 7 days. Subsequently, ΔR and ΔF changes in the lesions were measured. RESULTS: Significant interactions between lesion activity and time were found for both ΔR and ΔF (p < 0.001). ΔR of active lesions declined faster and ΔF increased more steeply than did inactive lesions. Specifically, on day 7 post-fluoride treatment, the ΔR reduction rate was 1.40-times higher in active lesions, and the ΔF recovery rate was 2.50-times higher, indicating that active lesions respond more markedly to fluoride application. CONCLUSIONS: This study highlighted the significance of ΔR in predicting remineralization efficiency in non-cavitated carious lesions after fluoride application. It underscored the importance of accurately assessing caries activity when formulating effective treatment plans. Lesion activity, as determined by ΔR, not only influences the outcome of remineralization treatments but also provides a more objective measure for tailoring caries management strategies.

Impact of channel nanostructures of porous carbon particles on their catalytic performance.

Mesoporous carbon particles have great potential due to their unique structural properties as support materials for catalytic applications. Particle shapes and channel nanostructures of mesoporous carbon particles can determine the reactant/product transport efficiency. However, the role of the channel nanostructure in the catalytic reaction has not been much explored. Herein, we introduce a facile method to fabricate a series of porous carbon particles (PCPs) with controlled channel exposure on the carbon surface and investigate the impact of the channel nanostructure of the PCPs on the catalytic activity. By employing a membrane emulsification method with a controlled solvent evaporation rate, we fabricate block copolymer (BCP) particles with uniform size and regulated degrees of cylindrical channel exposed to the particle surface. Followed by the carbonization of the BCP particles, a low amount (1.3 wt%) of Pt is incorporated into the PCP series to investigate the impact of channel nanostructures on the catalytic oxidation reaction of o-phenylenediamine (OPD). Specifically, PCP featuring highly open channel nanostructures shows a high reaction rate constant of 0.154 mM-1 s-1 for OPD oxidation, showing 5.5 times higher catalytic activity than those of closed channel nanostructures (0.028 mM-1 s-1). This study provides a deeper understanding of the impact of channel nanostructure within mesoporous carbon particles on catalytic activity.

The Prognostic Value of the Modified Surprise Question in Critically Ill Emergency Department Patients.

Objective: The initiation of palliative care (PC) in the emergency department (ED) is effective in improving the quality of life for seriously ill patients. This study aimed to evaluate the prognostic value of the modified surprise question (mSQ), "Would you be surprised if this patient died in the next 30 days?" as a trigger for initiating PC in critically ill ED patients. Methods: We conducted a prospective cohort study over a 6-month period in an ED, during which 22 emergency residents answered the mSQ for critically ill ED patients (Korean Triage and Acuity Scale 1 or 2). The primary outcome was the accuracy of the positive mSQ (negative response to the mSQ) in predicting 30-day mortality, and logistic regression analysis was performed to identify the prognostic factors. Results: A total of 300 patients were enrolled, and the positive mSQ group included 118 (39.3%) patients. The 30-day mortality rate of the cohort was 10.0%. The sensitivity, specificity, positive predictive value, and negative predictive value of the positive mSQ were 83.3%, 65.6%, 21.2%, and 97.3%, respectively, with a c-statistic of 0.74 and a positive likelihood ratio of 2.42. In a multivariable analysis controlling for clinically relevant variables, the odds ratio for 30-day mortality of the positive mSQ was 4.76 (95% confidence interval, 1.61-14.09; P = .005). Conclusions: The mSQ may be valuable for identifying critically ill ED patients with an increased risk of 30-day mortality. Therefore, it may be utilized as a trigger for PC consultation in the ED.

SAM-Support-Based Electrochemical Sensor for Aß Biomarker Detection of Alzheimer's Disease.

Alzheimer's disease has taken the spotlight as a neurodegenerative disease which has caused crucial issues to both society and the economy. Specifically, aging populations in developed countries face an increasingly serious problem due to the increasing budget for patient care and an inadequate labor force, and therefore a solution is urgently needed. Recently, diverse techniques for the detection of Alzheimer's biomarkers have been researched and developed to support early diagnosis and treatment. Among them, electrochemical biosensors and electrode modification proved their effectiveness in the detection of the Aß biomarker at appropriately low concentrations for practice and point-of-care application. This review discusses the production and detection ability of amyloid beta, an Alzheimer's biomarker, by electrochemical biosensors with SAM support for antibody conjugation. In addition, future perspectives on SAM for the improvement of electrochemical biosensors are also proposed and discussed.

Preparation and evaluation of injectable microsphere formulation for longer sustained release of donepezil.

In this study, donepezil-loaded PLGA and PLA microspheres (Dp-PLGA-M/Dp-PLA-M) and Dp-PLA-M wrapped in a polyethylene glycol-b-polycaprolactone (PC) hydrogel (Dp-PLA-M/PC) were prepared to reduce the dosing frequency of injections to treat Alzheimer's disease patients. Dp-PLGA-M and Dp-PLA-M with a uniform particle size distribution were repeatably fabricated in nearly quantitative yield and with high encapsulated Dp yields using an ultrasonic atomizer. The injectability and in vitro and in vivo Dp release, biodegradation, and inflammatory response elicited by the Dp-PLGA-M, Dp-PLA-M, and Dp-PLA-M/PC formulations were then compared. All injectable formulations showed good injectability with ease of injection, even flow, and no clogging using a syringe needle under 21-G. The injections required a force of <1 N. According to the biodegradation rate of micro-CT, GPC and NMR analyses, the biodegradation of Dp-PLA-M was slower than that of Dp-PLGA-M, and the biodegradation rate of Dp-PLA-M/PC was also slower. In the Dp release experiment, Dp-PLA-M sustained Dp for longer compared with Dp-PLGA-M. Dp-PLA-M/PC exhibited a longer sustained release pattern of two months. In vivo bioavailability of Dp-PLA-M/PC was almost 1.4 times higher than that of Dp-PLA-M and 1.9 times higher than that of Dp-PLGA-M. The variations in the Dp release patterns of Dp-PLGA-M and Dp-PLA-M were explained by differences in the degradation rates of PLGA and PLA. The sustained release of Dp by Dp-PLA-M/PC was attributed to the fact that the PC hydrogel served as a wrapping matrix for Dp-PLA-M, which could slow down the biodegradation of PLA-M, thus delaying the release of Dp from Dp-PLA-M. Dp-PLGA-M induced a higher inflammatory response compared to Dp-PLA-M/PC, suggesting that the rapid degradation of PLGA triggered a strong inflammatory response. In conclusion, Dp-PLA-M/PC is a promising injectable Dp formulation that could be used to reduce the dosing frequency of Dp injections.

Antimicrobial Effects of Non-Thermal Atmospheric Pressure Plasma on Oral Microcosm Biofilms.

We comparatively evaluated the antibacterial effects of non-thermal atmospheric pressure plasma (NTAPP) on oral microcosm biofilms. Oral microcosm biofilms, which are derived from inoculation with human saliva, were cultured on 48 hydroxyapatite disks for 6 days. The prepared biofilms were divided into three different daily treatment groups: distilled water for 1 min, 0.12% chlorhexidine (CHX) for 1 min, and NTAPP for 5 min. Using a quantitative light-induced fluorescence-digital camera, the red fluorescence intensity of the biofilms was measured as red/green ratios (RatioR/G) before and after treatment. Total and aciduric bacteria were counted as colony-forming units. Using live/dead bacterial staining, bacterial viability was calculated as the RatioG/G+R. RatioR/G was approximately 0.91-fold lower in the NTAPP group than in the CHX group on day 1 of treatment (p = 0.001), and approximately 0.94-fold lower on both days 2 and 3 (p < 0.001). The number of total bacteria was higher in the NTAPP group than in the CHX group, but not significantly different. The number of aciduric bacteria was lowest in the CHX group (p < 0.001). However, bacterial viability was lowest in the NTAPP group. Restricted bacterial aggregation was observed in the NTAPP group. These findings suggest that NTAPP may more effectively reduce the pathogenicity of oral microcosm biofilms than 0.12% CHX.

ASSOCIATIONS OF THE SERUM ALBUMIN CONCENTRATION AND SEQUENTIAL ORGAN FAILURE ASSESSMENT SCORE AT DISCHARGE WITH 1-YEAR MORTALITY IN SEPSIS SURVIVORS: A RETROSPECTIVE COHORT STUDY.

ABSTRACT: Introduction: This study was performed to investigate the predictors of 1-year mortality at discharge in sepsis survivors. Methods: This study was a retrospective analysis of patients with sepsis and septic shock at a single center. Patients who survived hospitalization for sepsis or septic shock between January 2016 and December 2017 were included in this study. Age, sex, body mass index, laboratory results such as blood cell count, C-reactive protein (CRP) and albumin levels, the Sequential Organ Failure Assessment (SOFA) score at the time of discharge and site of infection were compared between the survivors and nonsurvivors at 1 year postdischarge. Multivariate logistic regression was performed to identify the predictors of 1-year mortality. Results: During the study period, 725 sepsis patients were included in the analysis, 64 (8.8%) of whom died within the first year. The nonsurvivors were older and had a lower body mass index and a higher SOFA score at discharge than the survivors ( P < 0.05). Among the laboratory results at discharge, hemoglobin, platelet counts, and albumin concentrations were lower in the nonsurvivors than in the survivors, whereas CRP was higher in the nonsurvivors than in the survivors. In the multivariate logistic regression analysis, serum albumin <2.5 mg/dL and SOFA score ≥2 at discharge were identified as independent prognostic factors for 1-year mortality (odds ratio, 2.616; 95% confidence interval, 1.437-4.751 for albumin <2.5 mg/dL and 2.106, 1.199-3.801 for SOFA score ≥2, respectively). Conclusions: A low serum albumin concentration of <2.5 mg/dL and a high SOFA score of ≥2 at the time of discharge were prognostic factors for 1-year mortality in survivors of sepsis.

Factors Affecting Masticatory Performance of Older Adults Are Sex-Dependent: A Cross-Sectional Study.

This cross-sectional study assessed the oral and physical factors contributing to improvement of the masticatory performance of community-dwelling older adults in South Korea. We enrolled 84 healthy older adults (38 men, 46 women; age, 71.40 ± 5.15 years) and assessed their skeletal muscle mass index (SMI), functional tooth units (FTUs), and mixing ability index (MAI). Associations between variables were analyzed using Spearman's correlation coefficient, and the effects of SMI and FTUs on the MAI were evaluated through linear multiple regression. FTUs were positively associated with the MAI in men and women (r = 0.339, p = 0.038 and r = 0.461, p = 0.001, respectively). SMI and FTUs were moderately associated in men (r = 0.459, p = 0.004). MAI showed an approximately 4.4 times increase for each FTU in men (B = 4.442, p = 0.037); however, after the SMI was added, this effect was no longer significant. In women, the MAI increased by about 6.7 times with each FTU (B = 6.685, p = 0.004). FTUs had a significant effect on the MAI only in women with low muscle mass. While there was no significant effect of the SMI on the MAI, its influence should not be overlooked.

Injectable click-crosslinked hydrogel containing resveratrol to improve the therapeutic effect in triple negative breast cancer.

Triple-negative breast cancer (TNBC) patients are considered intractable, as this disease has few effective treatments and a very poor prognosis even in its early stages. Here, intratumoral therapy with resveratrol (Res), which has anticancer and metastasis inhibitory effects, was proposed for the effective treatment of TNBC. An injectable Res-loaded click-crosslinked hyaluronic acid (Res-Cx-HA) hydrogel was designed and intratumorally injected to generate a Res-Cx-HA depot inside the tumor. The Res-Cx-HA formulation exhibited good injectability into the tumor tissue, quick depot formation inside the tumor, and the depot remained inside the injected tumor for extended periods. In vivo formed Res-Cx-HA depots sustained Res inside the tumor for extended periods. More importantly, the bioavailability and therapeutic efficacy of Res remained almost exclusively within the tumor and not in other organs. Intratumoral injection of Res-Cx-HA in animal models resulted in significant negative tumor growth rates (i.e., the tumor volume decreased over time) coupled with large apoptotic cells and limited angiogenesis in tumors. Therefore, Res-Cx-HA intratumoral injection is a promising way to treat TNBC patients with high efficacy and minimal adverse effects.

Catalytic approaches towards highly durable proton exchange membrane fuel cells with minimized Pt use.

Proton exchange membrane fuel cells (PEMFCs) produce electricity from H2 without carbon emission, and they are considered as environmentally benign energy conversion devices. Although PEMFCs are mature enough to find themselves in a few commercial automobiles such as Hyundai Nexo and Toyota Mirai, their durability should be enhanced, especially under transient conditions, and Pt use should be reduced significantly to expand their market. Herein, we introduce examples of how catalysts can contribute to enhancing the durability of PEMFCs while minimizing Pt use. Numerous electrocatalysts have been reported claiming superior activity in a half-cell setup, but they often fail to show the same enhancement in a single cell setup due to various transfer problems, impurity poisoning, etc. This perspective focuses on catalysts tested in a membrane-electrode-assembly (MEA) setup. As examples to obtain durability under transient conditions, catalysts used in reversal-tolerant anodes (RTAs) and selective anodes are explained. RTAs can endure sudden H2 starvation, and selective anodes can operate properly when O2 is unexpectedly mixed with H2 in the anode. As examples with high durability in long-term operation, Pt-based nanoparticle catalysts encapsulated with carbon shells are explained. Interestingly, PtCo nanoparticles supported on Co-N-C or PtFe nanoparticles encapsulated with a carbon shell presented a superior cell performance in spite of <1/10 Pt use in an MEA setup. Non-Pt group metal (PGM) catalysts used in an MEA setup are also briefly explained. With these highly durable catalysts which can respond properly under transient conditions with minimum Pt use, PEMFC technology can bring about a more sustainable society.

Lens-Shaped Carbon Particles with Perpendicularly-Oriented Channels for High-Performance Proton Exchange Membrane Fuel Cells.

Two-dimensional sheet-like mesoporous carbon particles are promising for maximizing the number of active sites and the mass transport efficiency of proton exchange membrane fuel cells (PEMFCs). Herein, we develop a series of lens-shaped mesoporous carbon (LMC) particles with perpendicularly oriented channels (diameter = 60 nm) and aspect ratios (ARs) varying from 2.1 to 6.2 and apply them for the fabrication of highly efficient PEMFCs. The membrane emulsification affords uniform-sized, lens-shaped block copolymer particles, which are successfully converted into the LMC particles with well-ordered vertical channels through hyper-cross-linking and carbonization steps. Then, an ultralow amount (1 wt %) of platinum (Pt) is loaded into the particles. The LMC particles with higher ARs are packed with a higher density in the cathode and are better aligned on the cathode surface compared to the LMC particles with lower ARs. Thus, the well-ordered channels in the particles facilitate the mass transport of the reactants and products, significantly increasing the PEMFC performance. For example, the LMC particles with the AR of 6.2 show the highest initial single cell performance of 1135 mW cm-2, and the cell exhibits high durability with 1039 mW cm-2 even after 30 000 cycles. This cell performance surpasses that of commercial Pt/C catalysts, even at 1/20 of the Pt loading.

Advances in Injectable In Situ-Forming Hydrogels for Intratumoral Treatment.

Chemotherapy has been linked to a variety of severe side effects, and the bioavailability of current chemotherapeutic agents is generally low, which decreases their effectiveness. Therefore, there is an ongoing effort to develop drug delivery systems to increase the bioavailability of these agents and minimize their side effects. Among these, intratumoral injections using in situ-forming hydrogels can improve drugs' bioavailability and minimize drugs' accumulation in non-target organs or tissues. This review describes different types of injectable in situ-forming hydrogels and their intratumoral injection for cancer treatment, after which we discuss the antitumor effects of intratumoral injection of drug-loaded hydrogels. This review concludes with perspectives on the future applicability of, and challenges for, the adoption of this drug delivery technology.

Remineralizing efficacy of fluoride in the presence of oral microcosm biofilms.

OBJECTIVES: The oral biofilm structure or composition can affect the penetration of remineralizing agents. Therefore, this study evaluated the remineralizing efficacy of fluoride using a pH-cycling model with oral microcosm biofilms. METHODS: Artificial carious lesions were formed in 80 bovine incisors. The pH-cycling conditions with or without oral microcosm biofilms were applied to 40 specimens each. The pH-cycling scheme was repeated for 12 days. Fluorescence loss (ΔF,%) of early carious lesions was measured for all specimens using a quantitative light-induced fluorescence-digital camera, before and after fluoride application. Biofilms on specimens were further analyzed for red fluorescence intensity (red/green ratios) and colony-forming unit counts. The effects of pH-cycling conditions and treatments on changes in ΔF (ΔΔF) and the effects of interactions between factors were analyzed using two-way analysis of variance. RESULTS: The fluoride-treated group with oral biofilms had an approximately 0.89-fold lower ΔΔF than the fluoride-treated group without oral biofilms (p < 0.0001). When oral biofilms were absent, the fluoride-treated group showed a 1.31-fold greater ΔΔF compared to that in the distilled water-treated group (p < 0.0001). When oral biofilms were present, the fluoride-treated group showed a 1.14-fold greater ΔΔF compared to that in the distilled water-treated group; however, this difference was not statistically significant. CONCLUSIONS: There was a significant difference in fluoride remineralizing efficacy based on the presence of biofilms on early carious lesions. Therefore, fluoride remineralization assessment in the absence of oral biofilms could lead to an overestimation of efficacy. CLINICAL SIGNIFICANCE: Fluoride application might not have a robust remineralization effect on early carious lesions in the presence of a mature biofilm on the tooth surface.

Factors affecting subjective and objective masticatory function in older adults: Importance of an integrated approach.

OBJECTIVES: This study aimed to subjectively and objectively assess masticatory function and identify related factors in older adults. METHODS: From July 2017 to September 2018, we enrolled 115 healthy participants aged between 65 and 86 years. They underwent oral examination, and their stimulated salivary secretion rate and masseter muscle tone and biomechanical properties were assessed. Masticatory performance with two-colored chewing wax was objectively evaluated using the mixing ability index (MAI). Key food intake ability (KFIA) was subjectively assessed using a questionnaire. RESULTS: The MAI score was significantly associated with the number of remaining teeth (r = 0.524, p < 0.001) and the tone (r = -0.222, p = 0.017), elasticity (r = -0.242, p = 0.009), and dynamic stiffness (r = -0.265, p = 0.004) of the masseter muscles. In contrast, the KFIA score was only significantly associated with the number of remaining teeth (r = 0.450, p < 0.001). A weak association between the MAI and KFIA scores was observed (r = 0.304, p = 0.001). CONCLUSIONS: A combination of objective and subjective methods should be used to accurately assess masticatory function in older adults. In addition to physical factors such as the number of remaining teeth, properties of the masticatory muscles should be evaluated to improve the masticatory function of older adults. CLINICAL SIGNIFICANCE: In addition to dental problems, various maxillofacial and oral factors must be considered when establishing management strategies for the improvement of masticatory function in older adults.

Influential Factors of Masticatory Performance in Older Adults: A Cross-Sectional Study.

While appropriate nutrient intake is important for older adults, various oral problems cause decreased masticatory function. This cross-sectional study aimed to identify the factors associated with decreased masticatory performance in older adults. Oral examinations were performed on 80 participants (mean age: 75.10 ± 5.64 years) to determine the number of functional tooth units (FTUs). Symptoms of periodontal and temporomandibular diseases were evaluated via a questionnaire. The tone, elasticity, and dynamic stiffness of the masseter muscle were measured using the Myoton® PRO device. The mixing ability test was used to assess the masticatory performance, and the mixing ability index (MAI) was calculated. The analysis of covariance test was performed to adjust for confounding factors, and multiple logistic regression analysis was performed to identify the risk factors affecting MAI. A lower MAI was significantly associated with higher tone (p = 0.006) and lower elasticity (p = 0.013). The number of FTUs (adjusted odds ratio (OR) = 0.724, p = 0.029), tone (adjusted OR = 1.215, p = 0.016), and elasticity (adjusted OR = 4.789, p = 0.038) were independently associated with the MAI. Muscle function training and prosthetic treatments may help increase masticatory performance in older adults, which would improve overall health.

Relationship between Vitamin D Deficiency and Periodontitis in Korean Adults Aged ≥60 Years: Analysis of Data from the Korea National Health and Nutrition Examination Survey (2013-2014).

There have been contradictory reports on the effects of vitamin D in the prevention of periodontitis. We analyzed the association between vitamin D status (levels of plasma 25(OH)D) and periodontitis using the Korea National Health and Nutrition Examination Survey (KNHANES) 2013-2014 database. Among the participants in the KNHANES (2013-2014), only those aged ≥60 years who completed a health interview survey, periodontal examination, and blood test were included in the study. Thus, data from 701 participants were used in the final analysis. Periodontal status was evaluated using the Community Periodontal Index (CPI), and periodontitis was defined as having a CPI score of 3 or 4. Plasma 25(OH)D levels were classified according to two criteria: 20 ng/mL and quartile value. The chi-square test and multivariate logistic regression analyses were performed to analyze the prevalence of periodontitis according to plasma 25(OH)D levels. Univariate analyses showed that periodontitis was not significantly associated with plasma 25(OH)D levels. In the multivariate logistic regression model adjusted for sociodemographic characteristics, the difference in the prevalence of periodontitis between those with a normal range of 25(OH)D and those with low plasma of 25(OH)D levels was not statistically significant. Vitamin D intake has been reported to have benefits in maintaining periodontal health; however, total plasma 25(OH)D levels showed no significant association with periodontitis based on CPI scores in this study. Additionally, these findings reaffirmed the importance of toothbrushing and smoking cessation to prevent periodontitis in people aged ≥60 years.