Background: This study investigated the relationship between work-life balance (WLB), effort-reward imbalance (ERI), and presenteeism among Korean wageworkers through two models used simultaneously. Methods: Data from the 6th Korean Working Conditions Survey for 28,669 Korean workers, including 13,513 men and 15,156 women, were analyzed. All analyses were performed with pre-designed weight. Multiple logistic regression analysis was used to analyze the association between WLB, ERI, and presenteeism among Korean workers. The participants were classified into the following four groups: group 1, status of both WLB and ERI is “balanced”; group 2, WLB and ERI status are “imbalanced” and “balanced”, respectively; group 3, WLB and ERI status are “balanced” and “imbalanced”, respectively; group 4: status of both WLB and ERI is “imbalanced.” Results: We found that WLB and ERI were associated with presenteeism in both men and women. Depending on their WLB and ERI status, women generally had a higher tendency of presenteeism than men. Multiple logistic regression shows that, in most models and groups, there is an increased odds ratio (OR) for presenteeism in both men and women compared to the reference value. Moreover, the OR in both men and women gradually increased in groups 2, 3, and 4 compared with group 1. When considering both WLB and ERI status simultaneously, ERI had a greater impact on presenteeism than WLB. Furthermore, it was found that a synergistic effect of presenteeism manifests when both WLB and ERI are in a state of imbalance simultaneously. Conclusions Using the two models simultaneously, we found an association between WLB, ERI, and presenteeism according to sex with a synergistic effect among Korean workers. Our research suggests that active interventions targeting WLB and ERI are necessary to reduce presenteeism, which ultimately leads to decreased productivity.

Purpose: This study retrospectively investigated the long-term clinical and radiographic outcomes of a bone-level type, 2-piece, internal connection dental implant system characterized by coronal microthreads. Methods: A total of 872 implants placed in 284 patients were selected from 1,845 implants placed in 691 patients by experienced periodontists at Yonsei University Dental Hospital.These selected implants had been followed up for over 10 years and were included in the present study. A statistical evaluation of implant survival and treatment success, based on changes in marginal bone levels, was conducted using electronic records and consecutively taken radiographs. Results: Over a follow-up period of 12.3±2.0 years, 830 of the 872 implants remained intact, yielding a cumulative survival rate of 95.2% at the implant level and 88.4% at the patient level.The cumulative treatment success rates, characterized by marginal bone loss of less than 2 mm, stood at 87.0% for implants and 76.1% for patients. Among the 830 surviving implants, 113 fixtures were classified as ailing, with an average marginal bone loss of 4.09±1.44 mm.Cox regression analysis revealed that implants 8 mm in length or shorter were significantly more likely to fail or experience pathologic marginal bone resorption, with hazard ratios of 3.71 and 2.00, respectively (P<0.05). Conclusions The survival and treatment success of the investigated microthreaded, bone-level, 2-piece, internal connection implants were acceptable over a follow-up period exceeding 10 years. However, shorter dental implants exhibited a higher propensity for failure and excessive marginal bone loss.

Background: Alcohol consumption is a major risk factor for cancer, and when combined with smoking, the risk increases. Nevertheless, few studies have comprehensively evaluated the combined effects of alcohol consumption and smoking on the risk of various cancer types.Therefore, to assess these effects, we conducted a systematic review and meta-analysis. Methods: We performed a systematic search of five literature databases, focusing on cohort and case-control studies. Considering exposure levels, we quantified the combined effects of alcohol consumption and smoking on cancer risk and assessed multiplicative interaction effects. Results: Of 4,452 studies identified, 24 (4 cohort studies and 20 case-control studies) were included in the meta-analysis. We detected interaction effect of light alcohol and moderate smoking on head and neck cancer risk (relative risk [RR], 4.26; 95% confidence interval [CI], 2.50–7.26; I2 = 65%). A synergistic interaction was observed in heavy alcohol and heavy smoking group (RR, 35.24; 95% CI, 23.17–53.58; I2 = 69%). In more detailed cancer types, the interaction effect of heavy alcohol and heavy smoking was noticeable on oral (RR, 36.42; 95% CI, 24.62–53.87; I2 = 46%) and laryngeal (RR, 38.75; 95% CI, 19.25–78.01; I2 = 69%) cancer risk. Conclusion Our study provided a comprehensive summary of the combined effects of alcohol consumption and smoking on cancers. As their consumption increased, the synergy effect became more pronounced, and the synergy effect was evident especially for head and neck cancer. These findings provide additional evidence for the combined effect of alcohol and smoking in alcohol guidelines for cancer prevention.

OBJECTIVES: Alcohol consumption is a well-established risk factor for cancer. Despite extensive research into the relationship between alcohol consumption and cancer risk, the effect of light alcohol consumption on cancer risk remains a topic of debate. To contribute to this discourse, we conducted a comprehensive systematic review and meta-analysis. METHODS: Our systematic review aimed to investigate the associations between different levels of alcohol consumption and the risk of several cancer types. We focused on analyzing prospective associations using data from 139 cohort studies. Among them, 106 studies were included in the meta-analysis after a quantitative synthesis. RESULTS: Our analysis did not find a significant association between light alcohol consumption and all-cause cancer risk (relative risk, 1.02; 95% confidence interval, 0.99 to 1.04), but we observed a dose-response relationship. Light alcohol consumption was significantly associated with higher risks of esophageal, colorectal, and breast cancers. Light to moderate drinking was associated with elevated risks of esophageal, colorectal, laryngeal, and breast cancers. Heavy drinking was also found to contribute to the risk of stomach, liver, pancreas, and prostate cancers, thereby increasing the risk of almost all types of cancer. Additionally, females generally had lower cancer risks compared to males. CONCLUSIONS Our findings highlight that cancer risks extend beyond heavy alcohol consumption to include light alcohol consumption as well. These findings suggest that there is no safe level of alcohol consumption associated with cancer risk. Our results underscore the importance of public health interventions addressing alcohol consumption to mitigate cancer risks.

Background: Coronavirus disease 2019 (COVID-19) is generally asymptomatic or mild in otherwise healthy children, however, severe cases may occur. In this study, we report the clinical characteristics of children classified as critical COVID-19 in Korea to provide further insights into risk factors and management in children. Methods: This study was a retrospective case series of children < 18 years of age classified as critical COVID-19. Cases were identified by the Korea Disease Control and Prevention Agency surveillance system and medical records were reviewed. Critical COVID-19 was defined as cases with severe illness requiring noninvasive (high flow nasal cannula, continuous positive airway pressure, or bilevel positive airway pressure) or invasive mechanical ventilation, extracorporeal membrane oxygenation (ECMO) or continuous renal replacement therapy (CRRT), between January 20, 2020 and October 7, 2021. Results: Among 39,146 cases diagnosed with COVID-19 in subjects < 18 years of age, eight cases (0.02%) were identified as critical COVID-19. The median age was 13 years (range 10 month–17 years) and male-to-female ratio was 1:1. Three children had underlying diseases; one child has asthma and major depressive disorder, one child had LennoxGastaut syndrome and one child had mental retardation and was newly diagnosed with type 2 diabetes mellitus with the diagnosis of COVID-19. Among the eight children, seven were obese (body mass index range [BMI] median 29.3, range 25.9–38.2, weight-for-length > 97% for infant) and one was overweight (BMI 21.3). All patients had fever, six patients had dyspnea or cough and other accompanied symptoms included sore throat, headache, lethargy and myalgia. Radiologic findings showed pneumonia within 1–8 days after symptom onset. Pneumonia progressed in these children for 2–6 days and was improved within 5–32 days after diagnosis. Among the eight critical cases, remdesivir was administered in six cases.Steroids were provided for all cases. Inotropics were administered in one case. Six cases were treated with noninvasive mechanical ventilator and three required mechanical ventilator. One case required ECMO due to acute respiratory distress syndrome. All cases were admitted to the intensive care unit and admission period ranged from 9–39 days. Among all critical COVID-19 cases < 18 years of age, there were no fatal cases. Conclusion To develop appropriate policies for children in the COVID-19 pandemic, it is important to monitor and assess the clinical burden in this population.

Purpose: The aim of this study was to investigate the association between the changes in masticatory function and cognitive impairment by analyzing longitudinal data of older Korean patients. Materials and Methods: Patients aged over 60 years with dental records between 2005 to 2010 (baseline; T1) and 2014 to 2020 (follow-up; T2) were selected in a single medical center. Based on the dementia diagnosis after T2, the cohort was classified into two groups, the dementia group (n=122) and the control group (n=366). Changes in masticatory function were calculated using the total functional tooth unit (T-FTU) in both groups. The incidence of tooth extraction (%) and the subsequent rehabilitation during the observation period were also evaluated. Results: In the dementia group, T-FTU significantly decreased from T1 to T2 (9.81±2.78 to 9.11±3.16, respectively, p=0.008), while no significant change was observed in the control group. During the mean observation period of 9 years, significantly more teeth were extracted and neglected to be prosthetically restored in the dementia group than in the control group. Regression analysis revealed that the number of missing teeth neglected [odds ratio (OR)=1.195, 95% confidence interval (CI)=1.025–1.393, p=0.023] and previous alcohol consumption (OR=4.445, 95% CI=1.831–1.795, p=0.001) were the most significant risk factors of dementia. Conclusion There might be a causative relationship between the neglected missing dentition and the onset of dementia.

Objectives: The purpose of this study was to investigate the condylar morphology and position of Koreans using cone-beam computed tomography (CBCT) images. Analyzing the mean values of this study with reference to left and right sides, gender, and age will help to understand the size of the condyle and glenoid fossa, condylar morphology, and temporomandibular joint (TMJ) symmetry for establishing the standard temporomandibular joint structures of Koreans and then design the standard temporomandibular joint prosthesis for Koreans. Results: There was no significant result in the condyle size, condyle axis angle, joint space, fossa depth, and mandibular body size between the left and right sides (p > 0.05). On the other hand, the mediolateral width of the condyle and mandibular body size show significantly different with the gender (P < 0.05). Also, significant differences were found in condyle size, joint space, fossa depth, and mandibular body size according to age groups (P < 0.05). Conclusions Condylar position and morphology vary according to side, age, and gender. The results of this study are expected to help in customizing a treatment for the patients who need TMJ reconstruction by predicting the TMJ morphology according to age and gender and design the standard temporomandibular joint prosthesis for the Koreans.

With the introduction of life-course epidemiology, researchers realized the importance of identifying risk factors in early life to prevent chronic diseases. This led to the establishment of the Ewha Birth and Growth Study in 2001; the study is a prospective birth cohort designed to provide evidence of early life risk factors for a child’s growth and health. Participants were recruited from those who visited Ewha Womans University Mokdong Hospital (a tertiary hospital in southwest Seoul, Korea) for prenatal care at 24-28 weeks of gestation. In total, 891 mothers enrolled in this study between 2001 and 2006 and their offspring (n=940) were followed-up. Regular check-up examinations of offspring were conducted at 3 years, 5 years, and 7 years of age and every year thereafter. To consider age-related health issues, extensive data were collected using questionnaires and measurements. In 2021, the study subjects will reach 19 years of age, and we are planning a check-up examination for early adulthood. About 20 years have passed since the cohort data were collected, and we have published results on childhood health outcomes associated with prenatal and birth characteristics, genetic and epigenetic characteristics related to childhood metabolism, the effects of exposure to endocrine disruptors, and dietary patterns in childhood. Recently, we started reporting on topics related to adolescent health. The findings will facilitate identification of early life risk factors for chronic diseases and the development of interventions for diseases later in life.

With the introduction of life-course epidemiology, researchers realized the importance of identifying risk factors in early life to prevent chronic diseases. This led to the establishment of the Ewha Birth and Growth Study in 2001; the study is a prospective birth cohort designed to provide evidence of early life risk factors for a child’s growth and health. Participants were recruited from those who visited Ewha Womans University Mokdong Hospital (a tertiary hospital in southwest Seoul, Korea) for prenatal care at 24-28 weeks of gestation. In total, 891 mothers enrolled in this study between 2001 and 2006 and their offspring (n=940) were followed-up. Regular check-up examinations of offspring were conducted at 3 years, 5 years, and 7 years of age and every year thereafter. To consider age-related health issues, extensive data were collected using questionnaires and measurements. In 2021, the study subjects will reach 19 years of age, and we are planning a check-up examination for early adulthood. About 20 years have passed since the cohort data were collected, and we have published results on childhood health outcomes associated with prenatal and birth characteristics, genetic and epigenetic characteristics related to childhood metabolism, the effects of exposure to endocrine disruptors, and dietary patterns in childhood. Recently, we started reporting on topics related to adolescent health. The findings will facilitate identification of early life risk factors for chronic diseases and the development of interventions for diseases later in life.

Purpose: (i) To evaluate the biologic properties of a bi-layered 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride-cross-linked collagen membrane (CCM) In Vitro. (ii) To assess the efficacy of CCM for localized bone regeneration In Vivo. Materials and Methods: Biodegradation of CCM compared to a native collagen membrane (NCM) was assessed In Vitro. In Vivo, twelve male New Zealand White rabbits were used. Four calvarial, circular defects (diameter 8 mm) were created in each animal. The sites were randomly allocated to i) CCM+biphasic calcium phosphate (BCP) (CCM-BCP group), ii) CCM alone (CCM), iii) BCP alone (BCP) and, iv) negative control (control). Animals were sacrificed at 2 (n=6) and 8 weeks (n=6). Outcome measures included: micro-computed tomography (μCT) analysis (total augmented volume [TAV], new bone volume) and histomorphometry (total augmented area [TAA], newly formed bone, remaining membrane thickness [RMT]).Result: CCM was more resistant to degradation than NCM. μCT analysis showed CCM-BCP (196.43±25.30 mm 3 ) and BCP (206.23±39.13 mm 3 ) groups had significantly (P<0.01) larger TAV than the control (149.72±12.28 mm 3 ) after 8 weeks. Histomorphometrically, CCM-BCP group (17.75±5.97 mm 2 ) had significantly (P<0.01) greater TAA compared to the CCM group (7.74±2.25 mm 2 ) and the control (8.13±1.81 mm 2 ) after 8 weeks. After 8 weeks, RMT was reduced by 67%. Conclusion CCM can be a favorable choice of barrier membrane when performing guided bone regeneration (GBR) in localized bone defects. CCM has better resistance to degradation than the natural collagen membrane, In Vitro. In Vivo, CCM provides an advantageous integration of prolonged barrier function and biocompatibility for GBR.