1.Effects of clear aligner edentulous space design on distal canine movement: An iterative finite element analysis in cases involving extraction
Seung Eun BAEK ; Kiyean KIM ; Youn-Kyung CHOI ; Sung-Hun KIM ; Seong-Sik KIM ; Ki Beom KIM ; Yong-Il KIM
The Korean Journal of Orthodontics 2025;55(3):193-201
Objective:
Using finite element method (FEM) analysis of a clear aligner (CA), this study aimed to investigate the effects of varying the edentulous space on canine distal bodily movement during space closure following maxillary first premolar extraction.
Methods:
FEM analysis was used to simulate distal canine bodily movement following maxillary first premolar extraction using CAs. Four CA designs for edentulous spaces were compared: no-pontic, full-pontic, halfpontic, and beam. Three-dimensional models of the tooth components and CA were created. The target was set at a 0.25-mm distal canine movement. Long-term tooth movement was simulated using an iterative calculation method.
Results:
All the groups initially showed crown displacement, distal tipping, and distal rotation.Over time, the movement patterns differed in relation to the design. The no-pontic design exhibited the greatest displacement and tipping. The beam design exhibited the largest initial displacement but showed the lowest displacement and tipping thereafter. Full- and half-pontic designs yielded intermediate results. Significant force reduction was observed immediately after CA application, and was followed by a gradual decrease. The mean tooth-movement achievement rate was approximately 76.7%.
Conclusions
The edentulous space design of the CA substantially affected tooth-movement behavior. An iterative simulation is necessary to evaluate longterm tooth-movement patterns. The beam design demonstrated optimal suitability for bodily movement with minimal tipping. For optimal results, additional setup or overcorrection may be necessary.
2.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.
3.Validation of the Korean version of defense and veterans pain rating scale for assessment of postoperative pain: a prospective observational cohort study
Seungeun CHOI ; Taeyup KIM ; Hae Kyeong YOO ; Sang-Youn PARK ; Soo-Hyuk YOON ; Ho-Jin LEE
The Korean Journal of Pain 2025;38(1):58-68
Background:
The defense and veterans pain rating scale (DVPRS) is a pain assessment tool combining a numerical rating scale (NRS) with descriptive words, colors, and facial expressions. This study aimed to validate the Korean version of the DVPRS (K-DVPRS) for postoperative pain assessment.
Methods:
This study included patients who underwent elective laparoscopic or robotic abdominal surgery. The original DVPRS was translated into Korean using a forward-backward method. Pain intensities at rest and during coughing were assessed at 24 and 48 hours postoperatively using the NRS and K-DVPRS, respectively. The EuroQol 5-Dimension 5-Level (EQ-5D-5L) questionnaire was also used. The validity, reliability, and responsiveness of the K-DVPRS were evaluated.
Results:
Of the 174 patients screened, 150 were enrolled, and 148 completed the study. The K-DVPRS had strong convergent validity with the NRS at 24 and 48 hours postoperatively (ρ: 0.75 to 0.78, all P < 0.001). Construct validity was confirmed by significant differences in pain scores based on surgical extent and duration. The internal consistency was acceptable (Cronbach’s alpha: 0.77 and 0.85 at 24 and 48 hours, respectively), and test-retest reliability at 24 hours was excellent (intraclass correlation coefficient: 0.90 at rest and 0.95 during coughing).Responsiveness, measured by Cliff’s effect size, was high from preoperative to 24 hours postoperatively and moderate from 24 to 48 hours. At 48 hours, the K-DVPRS had stronger correlations with the EQ-5D-5L index and EQVAS than with the NRS.
Conclusions
The K-DVPRS is a valid, reliable, and responsive tool for assessing postoperative pain in Korean patients.
4.Reduction of Low-Density Lipoprotein Cholesterol by Mesenchymal Stem Cells in a Mouse Model of Exogenous Cushing’s Syndrome
Yu-Hee KIM ; Seonghee JEONG ; Kyung-Ah CHO ; So-Youn WOO ; Seung-Ho HAN ; Kyung-Ha RYU
Tissue Engineering and Regenerative Medicine 2025;22(2):237-248
BACKGROUND:
Exogenous Cushing’s syndrome, which results from prolonged glucocorticoid treatment, is associated with metabolic abnormalities. Previously, we reported the inhibitory effect of tonsil-derived mesenchymal stem cell conditioned medium (T-MSC CM) on glucocorticoid signal transduction. In this study, we investigated the therapeutic efficacy of T-MSCs in a mouse model of exogenous Cushing’s syndrome.
METHODS:
Exogenous Cushing’s syndrome model mice was generated by corticosterone administration in the drinking water for 5 weeks, and T-MSCs were injected intraperitoneally twice during the third week. Serum lipid profiles were measured using a chemistry analyzer. HepG2 cells were treated with dexamethasone and co-cultured with T-MSCs.Expression levels of genes involved in cholesterol metabolism were examined using real-time PCR. Low-density lipoprotein receptor (LDLR) protein levels were determined using western blotting and immunohistochemistry. Liver RNA extracted from the CORT and CORT ? MSC mouse groups was used for transcriptome sequencing analysis and protein– protein interaction analysis.
RESULTS:
Weight reduction and improvements in dyslipidemia by T-MSC administration were observed only in female mice. T-MSCs reduce circulating LDL cholesterol levels by downregulating liver X receptor a (LXRa) and inducible degrader of LDLR (IDOL) expression, thereby stabilizing LDLRs in the liver. Transcriptome analysis of liver tissue revealed pathways that are regulated by T-MSCs administration.
CONCLUSION
Administration of MSCs to female mice receiving chronic corticosterone treatment reduced the circulating LDL cholesterol level by downregulating the LXRa–IDOL axis in hepatocytes. These results suggest that T-MSCs may offer a novel therapeutic strategy for managing exogenous Cushing’s syndrome by regulating cholesterol metabolism.
5.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.
6.A Real-World, Prospective, Observational Study of Rivaroxaban on Prevention of Stroke and Non-Central Nervous Systemic Embolism in Renally Impaired Korean Patients With Non-Valvular Atrial Fibrillation:XARENAL
Il-Young OH ; Chang Hoon LEE ; Eue-Keun CHOI ; Hong Euy LIM ; Yong-Seog OH ; Jong-Il CHOI ; Min-Soo AHN ; Ju Youn KIM ; Nam-Ho KIM ; Namsik YOON ; Martin SANDMANN ; Kee-Joon CHOI
Korean Circulation Journal 2025;55(2):121-131
Background and Objectives:
Several real-world studies have been done in patients with nonvalvular atrial fibrillation (NVAF); however, information on its safety profile in patients with renal impairment is limited. XARENAL, a real-world study, aimed to prospectively investigate the safety profile of rivaroxaban in patients with NVAF with renal impairment (creatinine clearance [CrCl], 15–49 mL/min).
Methods:
XARENAL is an observational single-arm cohort study in renal impairment NVAF patients. Patients were followed up approximately every 3 months for 1 year or until 30 days following early discontinuation. The primary endpoint was major bleeding events. All adverse events, symptomatic thromboembolic events, treatment duration, and renal function change from baseline were the secondary endpoints.
Results:
XARENAL included 888 patients from 29 study sites. Overall, 713 (80.3%) had moderate renal impairment (CrCl, 30–49 mL/min), and 175 (19.7%) had severe renal impairment (CrCl, 15–29 mL/min) with a mean estimated glomerular filtration rate (eGFR) of 45.2±13.0 mL/min/1.73 m 2 . The mean risk scores were 3.3±1.4 and 1.7±0.9 for CHA 2 DS 2 -VASc score and HAS-BLED score, respectively. An incidence proportion of 5.6% (6.2 events per 100 patient-years) developed major bleeding; however, fatal bleeding occurred in 0.5% (0.5 events per 100 patient-years). The mean change in the eGFR was 2.22±26.47 mL/min/1.73 m 2 per year.
Conclusions
XARENAL observed no meaningful differences in major bleeding events from other previous findings as well as renal function changes in rivaroxaban-treated NVAF patients with renal impairment, which is considered to be acceptable in clinical practice.
7.Low Serum Creatinine as Well as High Serum Creatinine Is Associated with Prognosis of Patients with Cancer in End-of-Life
Yoo Jeong LEE ; Soon-Young HWANG ; Su Hyun KIM ; Youn Seon CHOI
Korean Journal of Family Medicine 2025;46(2):70-76
Background:
The prognosis of end-of-life patients is challenging, and clinicians have attempted to predict survival more accurately. High serum creatinine (sCr) levels are associated with lower survival rates in patients with various cancers; however, low sCr levels are commonly expected in patients with terminal cancer because of muscle wasting and malnutrition. Therefore, we investigated the prevalence of low and high sCr levels and their association with survival duration in patients with terminal cancer in a palliative care unit.
Methods:
We analyzed the medical records of 280 patients admitted to a palliative care unit. Patients were divided into low (<0.5 mg/dL), normal (0.5–1.2 mg/dL), and high (>1.2 mg/dL) sCr groups. Kaplan-Meier survival curves using sCr levels were plotted and compared using the log-rank test. Using stepwise selection, a multivariable Cox proportional hazards model was used to identify the significant prognostic factors.
Results:
The median survival durations in the high-, low-, and normal-sCr groups were 9.57 days, 22.26 days, and 27.51 days, respectively. Multivariable Cox proportional hazard model identified that males (hazard ratio [HR], 1.81; 95% confidence interval [CI], 1.16–2.85), poor performance status (HR, 3.43; 95% CI, 1.12–10.54), total parenteral nutrition use (HR, 1.84; 95% CI, 1.09–3.1), high sCr (HR, 2.74; 95% CI, 1.52–4.94), and low sCr (HR, 1.22; 95% CI, 1.07–1.43) were significantly associated with a shorter survival time.
Conclusion
Low and high serum creatinine levels were significantly associated with poor survival in patients with cancer at the end-of-life stage. Therefore, readily available and simple biomarkers may help plan advanced care in palliative care settings.
8.A single center experience on clinical outcome of fundoplication in pediatric patients: a retrospective cohort study
Yuyoung OH ; Joong Kee YOUN ; Hee-Beom YANG ; Hyun-Young KIM ; Dayoung KO
Annals of Surgical Treatment and Research 2025;108(3):177-185
Purpose:
The study aimed to evaluate the characteristics and operative-related factors in children who underwent fundoplication, analyze surgical outcomes categorized by disease entity and surgical indication, and identify prognostic factors for reoperation risk.
Methods:
A total of 109 pediatric patients who underwent fundoplication between 2008 and 2022 were retrospectively analyzed. Patients were grouped by disease entity and surgical indication. Underlying diseases, comorbidities, sex, gestational age, birth weight, preoperative symptoms, and operation-related factors were examined. Outcomes were classified as short-term and long-term adverse events. We investigated differences in clinical outcomes according to disease entity and surgical indication. Then we statistically identified preoperative predictors for the risk of reoperation.
Results:
The most common disease entity was neurological impairment (n = 92). Pulmonary comorbidity (42.2%) and aspiration/regurgitation (87.2%) were the most common. Most surgeries were performed laparoscopically (86.2%). There were 12 short-term and 25 long-term adverse events, with long-term events occurred more frequently in the neurological impairment (NIP) group compared to the non-NIP group (P = 0.04). None of the factors showed a significant relationship with the risk of reoperation.
Conclusion
Neurologically impaired children were more likely to experience long-term adverse events postfundoplication. However, no significant predictors for reoperation risk were identified.
9.Post-blepharoplasty ectropion management: therapeutic benefits of platelet-rich plasma and polydeoxyribonucleotide injections
Hyung Woo WANG ; Han Earl LEE ; Seong Oh PARK ; Youn Hwan KIM
Archives of Aesthetic Plastic Surgery 2025;31(2):41-45
Background:
Ectropion, a common complication after lower blepharoplasty, causes significant patient discomfort and dissatisfaction, yet effective treatments remain lacking. In this study, we evaluated the efficacy of intradermal injections of polydeoxyribonucleotide (PDRN) and platelet-rich plasma (PRP) for scar regeneration and the rapid recovery of temporary ectropion following lower blepharoplasty.
Methods:
This retrospective study analyzed 21 cases of ectropion among 420 patients who underwent transcutaneous lower blepharoplasty between January 2020 and October 2022. PDRN and PRP were injected intradermally into the lower eyelid, with patients monitored at 1- or 2-week intervals. We investigated patient satisfaction, the total number of injections administered, and the time to complete improvement of the ectropion.
Results:
The average time for complete ectropion resolution was 9.3 weeks, with a relatively high patient satisfaction rating (mean, 4.3 out of 5). Ten primary cases responded well to a single injection, whereas all six patients with previous operations required two or more injections. The rate of improvement was faster than previously reported, likely due to the enhanced collagen synthesis and anti-inflammatory effects of PDRN, along with the tissue repair and angiogenic properties of PRP.
Conclusions
Intradermal injections of PDRN and PRP demonstrated promising results in rapidly resolving ectropion after lower blepharoplasty, thereby reducing patient discomfort and increasing overall satisfaction.
10.Endoxifen Concentration Is Associated with Recurrence-Free Survival in Hormone-Sensitive Breast Cancer Patients
Beomki LEE ; Seok Jin NAM ; Seok Won KIM ; Jonghan YU ; Byung-Joo CHAE ; Se Kyung LEE ; Jai Min RYU ; Jeong Eon LEE ; Soo-Youn LEE
Cancer Research and Treatment 2025;57(1):140-149
Purpose:
The metabolism of tamoxifen is influenced by various cytochrome p450 enzymes, including CYP2D6 and CYP2C19, leading to variations in the levels of endoxifen, even with the same tamoxifen dose. However, the clinical significance of endoxifen for the prognosis of breast cancer patients remains controversial. This study aimed to elucidate the relevance of endoxifen level to recurrence-free survival censored with tamoxifen discontinuation (RFSt), representing the RFS for tamoxifen itself, of breast cancer patients and determine a suitable cutoff for prognostication.
Materials and Methods:
The study included 478 breast cancer patients. Tamoxifen and its metabolites, including endoxifen, were measured using liquid chromatography-tandem mass spectrometry. An optimal cutoff was determined with maximally selected rank statistics. Survival analysis and Cox regression were conducted based on this cutoff.
Results:
An endoxifen level of 21.00 ng/mL was the optimal cutoff for prognostication. Survival analysis revealed a statistically significant difference in RFSt between the low endoxifen group (≤ 21.00 ng/mL) and the high endoxifen group (> 21.00 ng/mL) (log-rank test, p=0.032). The 10-year probability of RFSt was 83.2% (95% confidence interval [CI], 77.0 to 89.9) and 88.3% (95% CI, 83.3 to 93.5) in the low and high endoxifen groups, respectively. Multivariable Cox proportional hazards regression indicated endoxifen concentration as a significant factor associated with prognosis.
Conclusion
Endoxifen could serve as a marker for appropriate tamoxifen treatment with a cutoff of 21.00 ng/mL. Based on this cutoff, therapeutic drug monitoring would benefit patients displaying suboptimal endoxifen concentrations.

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