1.Force and moment analysis of clear aligners: Impact of material properties and design on premolar rotation
Dong-Woo KIM ; Hyun-Jun LEE ; Ki Beom KIM ; Sung-Hun KIM ; Seong-Sik KIM ; Soo-Byung PARK ; Youn-Kyung CHOI ; Yong-Il KIM
The Korean Journal of Orthodontics 2025;55(3):212-223
Objective:
To quantitatively analyze and compare the forces and moments generated by thermoformed polyethylene terephthalate glycol (PETG) and direct-printed TC-85 clear aligners (CAs), with various margin designs, during premolar rotation.
Methods:
In total, 132 CAs were fabricated and divided into four groups (n = 33 per group). Group C consisted of thermoformed PETG aligners with a 2 mm gingival margin. Group E comprised direct-printed TC-85 aligners with equi-gingival margin, whereas Group G utilized direct-printed TC-85 aligners with 2 mm gingival margins.Finally, Group T featured direct-printed TC-85 aligners with an additional 1 mm thickness at the mesial embrasure. The forces and moments were measured using a 6-axis force/moment transducer at 2°, 3°, and 4° of rotation. All measurements were conducted at 37°C to simulate intraoral conditions. Forces were measured in the buccolingual, anteroposterior, and vertical directions, while moments were measured in the mesiodistal, buccolingual, and rotational planes.
Results:
The PETG aligners (Group C) showed significantly increased buccal and posterior force across the rotation angles (P < 0.05), whereas the intrusive force remained consistent. In contrast, the TC-85 aligners maintained consistent forces across all rotation angles.Direct-printed aligners demonstrated significantly lower intrusive forces than PETG aligners (P < 0.001). Group T exhibited reduced unwanted forces while maintaining effective rotational moments. Furthermore, all direct-printed aligners showed more predictable force delivery patterns than thermoformed aligners.
Conclusions
Direct-printed TC-85 aligners demonstrated superior force consistency and reduced unwanted side effects compared with traditional PETG aligners. Although marginal design modifications did not significantly improve rotational efficiency, they effectively reduced unwanted intrusive forces.
2.Clinical Profiles of Multidrug-Resistant and Rifampicin-Monoresistant Tuberculosis in Korea, 2018–2021: A Nationwide Cross-Sectional Study
Jinsoo MIN ; Yousang KO ; Hyung Woo KIM ; Hyeon-Kyoung KOO ; Jee Youn OH ; Doosoo JEON ; Taehoon LEE ; Young-Chul KIM ; Sung Chul LIM ; Sung Soon LEE ; Jae Seuk PARK ; Ju Sang KIM
Tuberculosis and Respiratory Diseases 2025;88(1):159-169
Background:
This study aimed to identify the clinical characteristics of multidrug-resistant/ rifampicin-resistant tuberculosis (MDR/RR-TB) in the Republic of Korea.
Methods:
Data of notified people with tuberculosis between July 2018 and December 2021 were retrieved from the Korea Tuberculosis Cohort database. MDR/RR-TB was further categorized according to isoniazid susceptibility as follows: multidrug-resistant tuberculosis (MDR-TB), rifampicin-monoresistant tuberculosis (RMR-TB), and RR-TB if susceptibility to isoniazid was unknown. Multivariable logistic regression analysis was conducted to identify the factors associated with MDR/RR-TB.
Results:
Between 2018 and 2021, the proportion of MDR/RR-TB cases among all TB cases and TB cases with known drug susceptibility test results was 2.1% (502/24,447). The proportions of MDR/RR-TB and MDR-TB cases among TB cases with known drug susceptibility test results were 3.3% (502/15,071) and 1.9% (292/15,071), respectively. Among all cases of rifampicin resistance, 31.7% (159/502) were RMR-TB and 10.2% (51/502) were RR-TB. Multivariable logistic regression analyses revealed that younger age, foreigners, and prior tuberculosis history were significantly associated with MDR/ RR-TB.
Conclusion
Rapid identification of rifampicin resistance targeting the high-risk populations, such as younger generations, foreign-born individuals, and previously treated patients are necessary for patient-centered care.
3.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.
4.2025 Seoul Consensus on Clinical Practice Guidelines for Irritable Bowel Syndrome
Yonghoon CHOI ; Young Hoon YOUN ; Seung Joo KANG ; Jeong Eun SHIN ; Young Sin CHO ; Yoon Suk JUNG ; Seung Yong SHIN ; Cheal Wung HUH ; Yoo Jin LEE ; Hoon Sup KOO ; Kwangwoo NAM ; Hong Sub LEE ; Dong Hyun KIM ; Ye Hyun PARK ; Min Cheol KIM ; Hyo Yeop SONG ; Sung-Hoon YOON ; Sang Yeol LEE ; Miyoung CHOI ; Moo-In PARK ; In-Kyung SUNG ;
Journal of Neurogastroenterology and Motility 2025;31(2):133-169
Irritable bowel syndrome (IBS) is a chronic, disabling, and functional bowel disorder that significantly affects social functioning and reduces quality of life and increases social costs. The Korean Society of Neurogastroenterology and Motility published clinical practice guidelines on the management of IBS based on a systematic review of the literature in 2017, and planned to revise these guidelines in light of new evidence on the pathophysiology, diagnosis, and management of IBS. The current revised version of the guidelines is consistent with the previous version and targets adults diagnosed with or suspected of having IBS. These guidelines were developed using a combination of de novo and adaptation methods, with analyses of existing guidelines and discussions within the committee, leading to the identification of key clinical questions. Finally, the guidelines consisted of 22 recommendations, including 3 concerning the definition and risk factors of IBS, 4 regarding diagnostic modalities and strategies, 2 regarding general management, and 13 regarding medical treatment. For each statement, the advantages, disadvantages, and precautions were thoroughly detailed. The modified Delphi method was used to achieve expert consensus to adopt the core recommendations of the guidelines. These guidelines serve as a reference for clinicians (including primary care physicians, general healthcare providers, medical students, residents, and other healthcare professionals) and patients, helping them to make informed decisions regarding IBS management.
5.Different Associations between Lipid Levels and Risk for Heart Failure according to Diabetes Progression
Seung-Hwan LEE ; Kyu Na LEE ; Jong-Chan YOUN ; Hun Sung KIM ; Kyungdo HAN ; Mee Kyoung KIM
Diabetes & Metabolism Journal 2025;49(1):105-116
Background:
The relationship between circulating lipid levels and the risk for heart failure (HF) is controversial. We aimed to examine this association, and whether it is modified by the duration of diabetes or treatment regimens in people with type 2 diabetes mellitus.
Methods:
Individuals (n=2,439,978) who underwent health examinations in 2015 to 2016 were identified from the Korean National Health Information Database. Subjects were categorized according to the duration of diabetes (new-onset, <5, 5–10, or ≥10 years) and number of antidiabetic medications. Incident HF was defined according to the International Classification of Diseases, 10th Revision (ICD-10) code I50 as the primary diagnosis during hospitalization. The risk for HF was estimated using multivariate Cox proportional hazard analysis.
Results:
During a median follow-up of 4.0 years, 151,624 cases of HF occurred. An inverse association between low-density lipoprotein cholesterol (LDL-C) levels and incident HF was observed in the new-onset diabetes group, with an approximately 25% lower risk in those with LDL-C levels of 100–129, 130–159, and ≥160 mg/dL, compared to those with levels <70 mg/dL. However, J-shaped associations were noted in the long-standing diabetes group, with a 16% higher risk in those with LDL-C level ≥160 mg/dL, compared to those with levels <70 mg/dL. Similar patterns were observed in the relationship between total cholesterol or non-high-density lipoprotein cholesterol and the risk for HF, and when subjects were grouped according to the number of antidiabetic medications instead of diabetes duration.
Conclusion
Different associations between lipid levels and the risk for HF were noted according to disease progression status among individuals with diabetes.
6.Volumetric Analysis Using an Automatic Whole-Brain Segmentation as a Biomarker for Idiopathic Normal Pressure Hydrocephalus
Chun Geun LIM ; Sung Won YOUN ; Yu Sung YOON ; Jihoon HONG ; Hui Joong LEE
Investigative Magnetic Resonance Imaging 2025;29(1):42-50
Purpose:
This study evaluated volumetric analysis using automatic whole-brain segmentation as a potential tool to enhance diagnostic accuracy alongside traditional magnetic resonance imaging (MRI) markers in the diagnosis of idiopathic normal pressure hydrocephalus (INPH).
Materials and Methods:
Twenty-six patients diagnosed with INPH exhibited progressive symptoms, including gait dysfunction and cognitive impairment, confirmed by MRI evidence of enlarged ventricles and normal cerebrospinal fluid pressure. Automatic segmentation was performed on sagittal T1-weighted volumetric images using LesionQuant. Age- and sex-matched groups with Alzheimer’s disease (AD) and normal control (NC) groups were included. Multinomial logistic regression was applied to predict diagnoses (NC, INPH, or AD) based on volumetric parameters.
Results:
Compared to the AD and NC groups, enlarged inferior lateral ventricles were observed in the INPH group. The inferior lateral ventricle volume showed a positive linear correlation with the Evans’ index (R2 = 0.639) and a negative linear correlation with the callosal angle (R2 = 0.482). High classification accuracy was achieved, with 87.5% of NC cases, 88.5% of INPH cases, and 76% of AD cases correctly identified.
Conclusion
Automated volumetric markers appear valuable for diagnosing INPH and distinguishing it from other neurodegenerative diseases.
7.Eligibility for Lecanemab Treatment in the Republic of Korea:Real-World Data From Memory Clinics
Sung Hoon KANG ; Jee Hyang JEONG ; Jung-Min PYUN ; Geon Ha KIM ; Young Ho PARK ; YongSoo SHIM ; Seong-Ho KOH ; Chi-Hun KIM ; Young Chul YOUN ; Dong Won YANG ; Hyuk-je LEE ; Han LEE ; Dain KIM ; Kyunghwa SUN ; So Young MOON ; Kee Hyung PARK ; Seong Hye CHOI
Journal of Clinical Neurology 2025;21(3):182-189
Background:
and Purpose We aimed to determine the proportion of Korean patients with early Alzheimer’s disease (AD) who are eligible to receive lecanemab based on the United States Appropriate Use Recommendations (US AUR), and also identify the barriers to this treatment.
Methods:
We retrospectively enrolled 6,132 patients with amnestic mild cognitive impairment or mild amnestic dementia at 13 hospitals from June 2023 to May 2024. Among them, 2,058 patients underwent amyloid positron emission tomography (PET) and 1,199 (58.3%) of these patients were amyloid-positive on PET. We excluded 732 patients who did not undergo brain magnetic resonance imaging between June 2023 and May 2024. Finally, 467 patients were included in the present study.
Results:
When applying the criteria of the US AUR, approximately 50% of patients with early AD were eligible to receive lecanemab treatment. Among the 467 included patients, 36.8% did not meet the inclusion criterion of a Mini-Mental State Examination (MMSE) score of ≥22.
Conclusions
Eligibility for lecanemab treatment was not restricted to Korean patients with early AD except for those with an MMSE score of ≥22. The MMSE criteria should therefore be reconsidered in areas with a higher proportion of older people, who tend to have lower levels of education.
8.A Nationwide Survey on Infection Prevention and Control in Acute Care Hospitals of Korea
Sun Hee NA ; Yubin SEO ; Hye Jin SHI ; In Sun HWANG ; Kyong A SHIN ; Kwang Yul SON ; Sung Ran KIM ; Myoungjin SHIN ; Hee-jung SON ; Ji Youn CHOI ; Heekyung CHUN ; Sook-Kyung PARK ; Jeongsuk SONG ; Namyi KIM ; Jacob LEE ; Joong Sik EOM
Journal of Korean Medical Science 2025;40(4):e41-
Background:
Healthcare-associated infections impose a significant burden on antibiotic usage, healthcare expenditures, and morbidity. Therefore, it is crucial to revise policies to minimize such losses. This nationwide survey aimed to evaluate infection prevention and control (IPC) components in healthcare facilities and encourage improvements in acute care hospitals with inadequate infection prevention settings. This study aims to enhance the infection control capabilities of healthcare facilities.
Methods:
From December 27, 2021, to May 13, 2022, we conducted a survey of 1,767 acute care hospitals in the Republic of Korea. A survey was conducted to evaluate the infection control components in 1,767 acute care hospitals. Infection control officers provided direct responses to a systematically developed questionnaire. Subsequently, 10% of the respondents were randomly selected for the site investigation.
Results:
Overall, 1,197 (67.7%) hospitals responded to the online survey. On-site investigations were conducted at 125 hospitals. Hospitals with ≥ 150 beds are advised to have an IPC team under Article 3 of the Medical Service Act; however, only 87.0% (598/687) of hospitals with ≥ 100 beds had one. Conversely, 22.7% (116/510) of hospitals with < 100 beds had an IPC team. Regulations for hand hygiene, waste management, healthcare worker protection and safety, environmental cleaning, standard precautions, and prevention of the transmission of multidrug-resistant pathogens were present in 84.2%, 80.1%, 77.4%, 76.2%, 75.8%, and 63.5% of the hospitals, respectively. Hospitals with < 100 beds had low availability of all categories of standard operating procedures.
Conclusion
This study is the first national survey of acute care hospitals in the Republic of Korea. The data presented in the current study will improve the understanding of IPC status and will help establish a survey system. Our survey provides a basis for improving policies related to IPC in healthcare facilities.
9.Prognostic Value of Ambulatory Status at Transplant in Older Heart Transplant Recipients: Implications for Organ Allocation Policy
Junho HYUN ; Jong-Chan YOUN ; Jung Ae HONG ; Darae KIM ; Jae-Joong KIM ; Myoung Soo KIM ; Jaewon OH ; Jin-Jin KIM ; Mi-Hyang JUNG ; In-Cheol KIM ; Sang-Eun LEE ; Jin Joo PARK ; Min-Seok KIM ; Sung-Ho JUNG ; Hyun-Jai CHO ; Hae-Young LEE ; Seok-Min KANG ; Dong-Ju CHOI ; Jon A. KOBASHIGAWA ; Josef STEHLIK ; Jin-Oh CHOI
Journal of Korean Medical Science 2025;40(3):e14-
Background:
Shortage of organ donors in the Republic of Korea has become a major problem. To address this, it has been questioned whether heart transplant (HTx) allocation should be modified to reduce priority of older patients. We aimed to evaluate post-HTx outcomes according to recipient age and specific pre-HTx conditions using a nationwide prospective cohort.
Methods:
We analyzed clinical characteristics of 628 patients from the Korean Organ Transplant Registry who received HTx from January 2015 to December 2020. Enrolled recipients were divided into three groups according to age. We also included comorbidities including ambulatory status. Non-ambulatory status was defined as pre-HTx support with either extracorporeal membrane oxygenation, continuous renal replacement therapy, or mechanical ventilation.
Results:
Of the 628 patients, 195 were < 50 years, 322 were 50–64 years and 111 were ≥ 65years at transplant. Four hundred nine (65.1%) were ambulatory and 219 (34.9%) were nonambulatory. Older recipients tended to have more comorbidities, ischemic cardiomyopathy, and received older donors. Post-HTx survival was significantly lower in older recipients (P = 0.025) and recipients with non-ambulatory status (P < 0.001). However, in contrast to non-ambulatory recipients who showed significant survival differences according to the recipient’s age (P = 0.004), ambulatory recipients showed comparable outcomes (P = 0.465).
Conclusion
Our results do not support use of age alone as an allocation criterion. Transplant candidate age in combination with some comorbidities such as non-ambulatory status may identify patients at a sufficiently elevated risk at which suitability of HTx should be reconsidered.
10.Nutrition Status and Comorbidities Are Important Factors Associated With Mortality During Anti-Tuberculosis Treatment
Oh Beom KWON ; Hyung Woo KIM ; Ju Sang KIM ; Eung Gu LEE ; Yeonhee PARK ; Sung Soo JUNG ; Jin Woo KIM ; Jee Youn OH ; Sang Haak LEE ; Seunghoon KIM ; Sun-Hyung KIM ; Jiwon LYU ; Yousang KO ; Sun Jung KWON ; Ganghee CHAE ; Jinsoo MIN
Journal of Korean Medical Science 2025;40(17):e73-
Background:
The increasing incidence and mortality rates of tuberculosis among older individuals who suffer from multiple morbidities and are vulnerable to malnutrition are major obstacles to efforts to eradicate tuberculosis in the Republic of Korea. Herein, we identified the factors associated with mortality during anti-tuberculosis treatment in patients with pulmonary tuberculosis.
Methods:
We conducted a case-control study and extracted data from the database of a multi-center prospective observational cohort study in Korea. Among the participants with rifampicin-susceptible pulmonary tuberculosis, the survival group was defined as those who successfully completed treatment within one year, whereas the mortality group was defined as those who died during treatment. Univariable and multivariable logistic regression analyses were performed to identify factors associated with TB mortality.
Results:
Among 1,119 participants with pulmonary TB registered between 2019 and 2021, 799 and 59 were grouped in the survival and mortality groups, respectively. Age, positive smear results, alarming symptoms, nutrition risk score, Charlson comorbidity index score, and initial standard treatment regimen were significant based on univariable analysis and were selected for the multivariable logistic regression model. Nutrition risk score (adjusted odds ratio, 2.44; 95% confidence interval, 1.72–3.48) and Charlson comorbidity index score (adjusted odds ratio, 1.62; 95% confidence interval, 1.35–1.94) remained statistically significant in the multivariate analysis.
Conclusion
Nutritional status and comorbidities at baseline were identified as important factors associated with mortality in patients with pulmonary tuberculosis.

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