1.Effect of Occlusal and Margin Design on the Fracture Load of Zirconia-Lithium Disilicate Bi-layered Posterior Crowns: An in Vitro Study
Sung-Hoon KIM ; Kyung-Ho KO ; Chan-Jin PARK ; Lee-Ra CHO ; Yoon-Hyuk HUH
Journal of Korean Dental Science 2025;18(1):1-11
		                        		
		                        			 Purpose:
		                        			The opacity of zirconia sometimes requires a veneering material; thus lithium disilicate, a veneer material with excellent strength, can be used. This study investigated the fracture resistance of zirconia–lithium disilicate (Zr-LS2) bi-layered crowns according to the design of the substructure.  
		                        		
		                        			Materials and Methods:
		                        			Five groups of posterior Zr-LS2 restorations (Zirtooth and Amber LiSi-POZ) were fabricated with different zirconia substructure coverage (control group, groups half occlusal zirconia coverage; 1/2OZ, and three-quarter occlusal zirconia coverage; 3/4OZ) and margin designs (control group, groups collar margin; C-M, and collarless margin; Cl-M). All restorations were cemented with self-adhesive resin cement followed by 24-h water storage and thermocycling (10,000 cycles, 5°C and 55°C). The fracture load was measured, and failure mode analysis, fractography, and elemental analysis were performed. The one-way analysis of variance and Fisher’s exact test were performed for statistical analyses (α=.05).  
		                        		
		                        			Results:
		                        			A significant difference was found in the fracture load of Zr-LS2 restorations according to the zirconia coverage of the occlusal area and margin design (P<.05). Group 3/4OZ was significantly larger than the control group C and 1/2OZ (P<.05). The C-M group had greater fracture loads based on margin design than the control group C and Cl-M (P<.05).  
		                        		
		                        			Conclusion
		                        			The fracture resistance of posterior Zr-LS2 restorations increased with the zirconia coverage, occlusal thickness, and collar margin. 
		                        		
		                        		
		                        		
		                        	
2.The Older the Patients, the More Aggressive the Prostate Cancer Detected Even Among Those With a Prostate-Specific Antigen Level Below the Low-Risk Threshold: Analysis Using Nationwide Korean Data
Jong Hyun PYUN ; Young Hwii KO ; Sang Won KIM ; Sung Gu KANG ; Nak-Hoon SON
Journal of Korean Medical Science 2025;40(15):e57-
		                        		
		                        			 Background:
		                        			To investigate the clinicopathologic pattern of prostate cancer (PCa) in elderly patients compared with their younger counterparts with a prostate-specific antigen (PSA) level below the low-risk threshold (< 10 ng/mL), which is often a deciding factor for biopsy. 
		                        		
		                        			Methods:
		                        			A nationwide database of PCa at the time of biopsy from 2010 to 2020 was constructed from 39 hospitals. Patients were categorized into age groups of < 64 years, 65–69 years, 70–74 years, and ≥ 75 years considering guidelines that recommend PSA testing only for those aged 55–69 years during the study period, the average age of Korean PCa registrants of 70.3 years (2010–2020), and the average life expectancy of Korean males of 80.3 years (2020). 
		                        		
		                        			Results:
		                        			The mean ± standard deviation age was 70.3 ± 8.2 years, which was normally distributed (kurtosis = 0.095). Among 14,548 subjects, 54.1%, 39.5%, and 6.4% of them had high-risk disease, intermediate-risk disease, and low-risk disease, respectively. Based on three risk parameters, a marked increase in high-risk cancer was observed in the oldest age group (linear combination, P < 0.001). The same pattern was observed among patients with low-risk disease (PSA < 10 ng/mL), who were divided into PSA tiers as follows: 4–5 ng/mL (P < 0.001), 5–6 ng/mL (P < 0.001), 6–7 ng/mL (P < 0.001), 7–8 ng/mL (P < 0.001), 8–9 ng/mL (P = 0.009), and 9–10 ng/mL (P < 0.001). In all PSA tiers between 4 and 10 ng/mL, multivariate analysis demonstrated a significantly higher prevalence of high-risk cancer in the oldest age group than in the youngest age group. In the lowest tier (4–5 ng/mL), 35.2% of those aged over 75 years had high-risk PCa. 
		                        		
		                        			Conclusion
		                        			The older the patient, the more aggressive the PCa. Moreover, there was an increase in high-risk PCa in older males compared with younger males even with a PSA level below the low-risk threshold of 10 ng/mL, suggesting the need to strengthen cancer screening policies in the older population. 
		                        		
		                        		
		                        		
		                        	
3.Explainability Enhanced Machine Learning Model for Classifying Intellectual Disability and AttentionDeficit/Hyperactivity Disorder With Psychological Test Reports
Tong Min KIM ; Young-Hoon KIM ; Sung-Hee SONG ; In-Young CHOI ; Dai-Jin KIM ; Taehoon KO
Journal of Korean Medical Science 2025;40(11):e26-
		                        		
		                        			 Background:
		                        			Psychological test reports are essential in assessing intellectual functioning, aiding in diagnosing and treating intellectual disability (ID) and attention-deficit/ hyperactivity disorder (ADHD). However, these reports can have several problems because they are diverse, unstructured, subjective, and involve human errors. Additionally, physicians often do not read the entire report, and the number of reports is lower than that of diagnoses. 
		                        		
		                        			Methods:
		                        			We developed explainable predictive models for classifying IDs and ADHDs based on written reports to address these issues. The reports of 1,475 patients with IDs and ADHDs who underwent intelligence tests were used for the models. These models were developed by analyzing reports using natural language processing (NLP) and incorporating the physician’s diagnosis for each report. We selected n-gram features from the models’ results by extracting important features using SHapley Additive exPlanations and permutation importance to make the models explainable. Developing the n-gram feature-based original text search system compensated for the lack of human readability caused by NLP and enabled the reconstruction of human-readable texts from the selected n-gram features. 
		                        		
		                        			Results:
		                        			The maximum model accuracy was 0.92, and the 80 human-readable texts were restored from four models. 
		                        		
		                        			Conclusion
		                        			The results showed that the models could accurately classify IDs and ADHDs, even with a few reports. The models were also able to explain their predictions. The explainability-enhanced model can help physicians understand the classification process of IDs and ADHDs and provide evidence-based insights. 
		                        		
		                        		
		                        		
		                        	
4.Rapid Recovery From SARS-CoV-2Infection Among Immunocompromised Children Despite Limited Neutralizing Antibody Response: A Virologic and Sero-Immunologic Analysis of a Single-Center Cohort
Doo Ri KIM ; Byoung Kwon PARK ; Jin Yang BAEK ; Areum SHIN ; Ji Won LEE ; Hee Young JU ; Hee Won CHO ; Keon Hee YOO ; Ki Woong SUNG ; Chae-Hong JEONG ; Tae Yeul KIM ; June-Young KOH ; Jae-Hoon KO ; Yae-Jean KIM
Journal of Korean Medical Science 2025;40(12):e52-
		                        		
		                        			 Background:
		                        			Immunocompromised (IC) pediatric patients are at increased risk of severe acute respiratory syndrome coronavirus 2 infection, but the viral kinetics and seroimmunologic response in pediatric IC patients are not fully understood. 
		                        		
		                        			Methods:
		                        			From April to June 2022, a prospective cohort study was conducted. IC pediatric patients hospitalized for coronavirus disease 2019 (COVID-19) were enrolled. Serial saliva swab and serum specimens were subjected to reverse transcription polymerase chain reaction assays with mutation sequencing, viral culture, anti-spike-protein, anti-nucleocapsid antibody assays, plaque reduction neutralization test (PRNT) and multiplex cytokine assays. 
		                        		
		                        			Results:
		                        			Eleven IC children were evaluated. Their COVID-19 symptoms resolved promptly (median, 2.5 days; interquartile range, 2.0–4.3). Saliva swab specimens contained lower viral loads than nasopharyngeal swabs (P = 0.008). All cases were BA.2 infection, and 45.5% tested negative within 14 days by saliva swab from symptom onset. Eight (72.7%) showed a time-dependent increase in BA.2 PRNT titers, followed by rapid waning. Multiplex cytokine assays revealed that monocyte/macrophage activation and Th 1 responses were comparable to those of non-IC adults. Activation of interleukin (IL)-1Ra and IL-6 was brief, and IL-17A was suppressed. Activated interferon (IFN)-γ and IL-18/IL-1F4 signals were observed. 
		                        		
		                        			Conclusion
		                        			IC pediatric patients rapidly recovered from COVID-19 with low viral loads.Antibody response was limited, but cytokine analysis suggested an enhanced IFN-γ- and IL-18-mediated immune response without excessive activation of inflammatory cascades. To validate our observation, immune cell-based functional studies need to be conducted among IC and non-IC children. 
		                        		
		                        		
		                        		
		                        	
5.Effect of Occlusal and Margin Design on the Fracture Load of Zirconia-Lithium Disilicate Bi-layered Posterior Crowns: An in Vitro Study
Sung-Hoon KIM ; Kyung-Ho KO ; Chan-Jin PARK ; Lee-Ra CHO ; Yoon-Hyuk HUH
Journal of Korean Dental Science 2025;18(1):1-11
		                        		
		                        			 Purpose:
		                        			The opacity of zirconia sometimes requires a veneering material; thus lithium disilicate, a veneer material with excellent strength, can be used. This study investigated the fracture resistance of zirconia–lithium disilicate (Zr-LS2) bi-layered crowns according to the design of the substructure.  
		                        		
		                        			Materials and Methods:
		                        			Five groups of posterior Zr-LS2 restorations (Zirtooth and Amber LiSi-POZ) were fabricated with different zirconia substructure coverage (control group, groups half occlusal zirconia coverage; 1/2OZ, and three-quarter occlusal zirconia coverage; 3/4OZ) and margin designs (control group, groups collar margin; C-M, and collarless margin; Cl-M). All restorations were cemented with self-adhesive resin cement followed by 24-h water storage and thermocycling (10,000 cycles, 5°C and 55°C). The fracture load was measured, and failure mode analysis, fractography, and elemental analysis were performed. The one-way analysis of variance and Fisher’s exact test were performed for statistical analyses (α=.05).  
		                        		
		                        			Results:
		                        			A significant difference was found in the fracture load of Zr-LS2 restorations according to the zirconia coverage of the occlusal area and margin design (P<.05). Group 3/4OZ was significantly larger than the control group C and 1/2OZ (P<.05). The C-M group had greater fracture loads based on margin design than the control group C and Cl-M (P<.05).  
		                        		
		                        			Conclusion
		                        			The fracture resistance of posterior Zr-LS2 restorations increased with the zirconia coverage, occlusal thickness, and collar margin. 
		                        		
		                        		
		                        		
		                        	
6.Risk Factors Associated with Middle Ear Barotrauma in Patients Undergoing Monoplace Hyperbaric Oxygen Therapy
Yoon Sung LEE ; Sang Won KO ; Hyoung Youn LEE ; Kyung Hoon SUN ; Tag HEO ; Sung Min LEE
Yonsei Medical Journal 2025;66(5):302-309
		                        		
		                        			 Purpose:
		                        			This study aimed to identify independent risk factors for middle ear barotrauma (MEB) symptoms in patients undergoing monoplace hyperbaric oxygen therapy (HBOT). 
		                        		
		                        			Materials and Methods:
		                        			We analyzed data from a single-center study involving 296 patients who received monoplace HBOT.Through multivariable logistic regression analysis, we examined the relationship between various factors and the occurrence of MEB to identify significant independent risk factors. 
		                        		
		                        			Results:
		                        			The multivariable logistic regression analysis indicated that an altered mental state was associated with increased odds of MEB occurrence [odds ratio (OR) 2.50; 95% confidence interval (CI): 1.13–5.51]. Furthermore, patients in the emergency treatment group for HBOT, as defined by the national health insurance in Korea, were found to be 6.75 times more likely to experience MEB (95% CI: 1.33–34.20). 
		                        		
		                        			Conclusion
		                        			This study identified altered mental status and classification in the emergency treatment group for monoplace HBOT as independent risk factors for MEB. These findings can aid in developing safer protocols for monoplace HBOT chamber operations. 
		                        		
		                        		
		                        		
		                        	
7.Characteristics and Prevalence of Sequelae after COVID-19: A Longitudinal Cohort Study
Se Ju LEE ; Yae Jee BAEK ; Su Hwan LEE ; Jung Ho KIM ; Jin Young AHN ; Jooyun KIM ; Ji Hoon JEON ; Hyeri SEOK ; Won Suk CHOI ; Dae Won PARK ; Yunsang CHOI ; Kyoung-Ho SONG ; Eu Suk KIM ; Hong Bin KIM ; Jae-Hoon KO ; Kyong Ran PECK ; Jae-Phil CHOI ; Jun Hyoung KIM ; Hee-Sung KIM ; Hye Won JEONG ; Jun Yong CHOI
Infection and Chemotherapy 2025;57(1):72-80
		                        		
		                        			 Background:
		                        			The World Health Organization has declared the end of the coronavirus disease 2019 (COVID-19) public health emergency. However, this did not indicate the end of COVID-19. Several months after the infection, numerous patients complain of respiratory or nonspecific symptoms; this condition is called long COVID. Even patients with mild COVID-19 can experience long COVID, thus the burden of long COVID remains considerable. Therefore, we conducted this study to comprehensively analyze the effects of long COVID using multi-faceted assessments. 
		                        		
		                        			Materials and Methods:
		                        			We conducted a prospective cohort study involving patients diagnosed with COVID-19 between February 2020 and September 2021 in six tertiary hospitals in Korea. Patients were followed up at 1, 3, 6, 12, 18, and 24 months after discharge. Long COVID was defined as the persistence of three or more COVID-19-related symptoms. The primary outcome of this study was the prevalence of long COVID after the period of COVID-19. 
		                        		
		                        			Results:
		                        			During the study period, 290 patients were enrolled. Among them, 54.5 and 34.6% experienced long COVID within 6 months and after more than 18 months, respectively. Several patients showed abnormal results when tested for post-traumatic stress disorder (17.4%) and anxiety (31.9%) after 18 months. In patients who underwent follow-up chest computed tomography 18 months after COVID-19, abnormal findings remained at 51.9%. Males (odds ratio [OR], 0.17; 95% confidence interval [CI], 0.05–0.53; P=0.004) and elderly (OR, 1.04; 95% CI, 1.00–1.09; P=0.04) showed a significant association with long COVID after 12–18 months in a multivariable logistic regression analysis. 
		                        		
		                        			Conclusion
		                        			Many patients still showed long COVID after 18 months post SARS-CoV-2 infection. When managing these patients, the assessment of multiple aspects is necessary. 
		                        		
		                        		
		                        		
		                        	
8.Diabetes Fact Sheets in Korea 2024
Se Eun PARK ; Seung-Hyun KO ; Ji Yoon KIM ; Kyuho KIM ; Joon Ho MOON ; Nam Hoon KIM ; Kyung Do HAN ; Sung Hee CHOI ; Bong Soo CHA
Diabetes & Metabolism Journal 2025;49(1):24-33
		                        		
		                        			 Background:
		                        			This study aimed to investigate the prevalence, management, and comorbidities of diabetes mellitus among Korean adults. 
		                        		
		                        			Methods:
		                        			Data from the Korea National Health and Nutrition Examination Survey (2019–2022) were analyzed to assess the prevalence, treatment, risk factors, and comorbidities of diabetes. Comparisons between young and older adults with diabetes were emphasized. 
		                        		
		                        			Results:
		                        			Among Korean adults aged ≥30 years, the prevalence of diabetes is 15.5% during 2021–2022. Of these, 74.7% were aware of their condition, 70.9% received antidiabetic treatment, and only 32.4% achieved glycosylated hemoglobin (HbA1c) <6.5%. Moreover, 15.9% met the integrated management targets, which included HbA1c <6.5%, blood pressure <140/85 mm Hg, and low-density lipoprotein cholesterol <100 mg/dL. In young adults aged 19 to 39 years, the prevalence of diabetes was 2.2%. Among them, 43.3% were aware of their condition, 34.6% received treatment, and 29.6% achieved HbA1c <6.5%. Obesity affected 87.1%, and 26.9% had both hypertension and hypercholesterolemia. Among adults aged ≥65 years, the prevalence of diabetes was 29.3%, with awareness, treatment, and control rates of 78.8%, 75.7%, and 31.2%, respectively. Integrated management targets (HbA1c <7.5%, hypertension, and lipids) were achieved by 40.1%. 
		                        		
		                        			Conclusion
		                        			Diabetes mellitus remains highly prevalent among Korean adults, with significant gaps in integrated glycemic, blood pressure, and lipid control. Older adults with diabetes show higher awareness and treatment rates but limited integrated management outcomes. Young adults with diabetes bear a significant burden of obesity and comorbidities, alongside low awareness and treatment rates. Therefore, early intervention programs, education, and strategies tailored to younger populations are urgently required. 
		                        		
		                        		
		                        		
		                        	
9.Prevalence, Incidence, and Metabolic Characteristics of Young Adults with Type 2 Diabetes Mellitus in South Korea (2010–2020)
Ji Yoon KIM ; Jiyoon LEE ; Joon Ho MOON ; Se Eun PARK ; Seung-Hyun KO ; Sung Hee CHOI ; Nam Hoon KIM
Diabetes & Metabolism Journal 2025;49(2):172-182
		                        		
		                        			 Background:
		                        			This study aimed to examine trends in the prevalence, incidence, metabolic characteristics, and management of type 2 diabetes mellitus (T2DM) among young adults in South Korea. 
		                        		
		                        			Methods:
		                        			Young adults with T2DM were defined as individuals aged 19 to 39 years who met the diagnostic criteria for T2DM. Data from the Korean National Health Insurance Service-Customized Database (2010–2020, n=225,497–372,726) were analyzed to evaluate trends in T2DM prevalence, incidence, metabolic profiles, comorbidities, and antidiabetic drug prescription. Additional analyses were performed using the Korea National Health and Nutrition Examination Survey. 
		                        		
		                        			Results:
		                        			The prevalence of T2DM in young adults significantly increased from 1.02% in 2010 to 2.02% in 2020 (P<0.001), corresponding to 372,726 patients in 2020. Over the same period, the incidence rate remained stable within the range of 0.36% to 0.45%. Prediabetes prevalence steadily increased from 15.53% to 20.92%, affecting 3.87 million individuals in 2020. The proportion of young adults with T2DM who were obese also increased, with 67.8% having a body mass index (BMI) ≥25 kg/m² and 31.6% having a BMI ≥30 kg/m² in 2020. The prevalence of hypertension, dyslipidemia, and fatty liver disease also increased, reaching 34.2%, 79.8%, and 78.9%, respectively, in 2020. Although the overall pharmacological treatment rate remained low, the prescription of antidiabetic medications with weight-reducing properties increased over the study period. 
		                        		
		                        			Conclusion
		                        			The prevalence of T2DM among young adults in South Korea nearly doubled over the past decade. The strong association with obesity and metabolic comorbidities emphasizes the urgent need for targeted prevention and management strategies tailored to this population. 
		                        		
		                        		
		                        		
		                        	
10.Diabetes Fact Sheets in Korea 2024
Se Eun PARK ; Seung-Hyun KO ; Ji Yoon KIM ; Kyuho KIM ; Joon Ho MOON ; Nam Hoon KIM ; Kyung Do HAN ; Sung Hee CHOI ; Bong Soo CHA
Diabetes & Metabolism Journal 2025;49(3):524-524
		                        		
		                        		
		                        		
		                        	
            
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