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.Can It be Said that this Case Confirmed the Phenomenon of Subacromial Suture Knot Impingement after Arthroscopic Rotator Cuff Repair?: A Case Report
Sung Hwan KIM ; Seung Won CHOI ; Sin Hyung PARK ; Yong Bok PARK
The Korean Journal of Sports Medicine 2025;43(1):41-45
Rotator cuff tears are common shoulder injuries, particularly in older adults. Arthroscopic rotator cuff repair (ARCR) is the preferred treatment due to its successful outcomes, but complications like suture knot impingement may arise.Knot impingement, although rare, can lead to subacromial bone erosion and persistent pain. The condition remains under-reported, and direct evidence linking knot impingement to subacromial erosion is scarce. A 63-year-old woman presented with progressively worsening shoulder pain and restricted range of motion, 10 years after undergoing ARCR. Clinical assessment indicated subacromial impingement with positive Neer, Hawkins test results and reduced shoulder mobility. Arthroscopic evaluation revealed suture knots embedded in the subacromial bone, directly causing erosion. This is the first case to confirm through arthroscopy that subacromial bone erosion resulted from knot impingement. This case emphasizes the importance of follow-up and highlights the need to consider alternative suture techniques to avoid complications like knot impingement. Surgeons should be vigilant in minimizing risks associated with suture materials and techniques to improve long-term outcomes for patients undergoing ARCR.
3.Radial Type Low-Intensity Extracorporeal Shockwave Therapy Enhances Penile Microvascular Perfusion in an Aging Rat Model: A Novel Interventional Strategy to Treat Erectile Dysfunction
Saager Tilak CHAWLA ; Jad SHAHAN ; Nolan SOUTIPAN ; Samuel Ryan SORKHI ; Yong Sun CHOI ; Woong Jin BAE ; Sae Woong KIM ; Tung-Chin HSIEH ; Mahadevan Raj RAJASEKARAN
The World Journal of Men's Health 2025;43(2):396-406
Purpose:
Physiological aging is associated with microvascular dysfunction, including in the penis, and this may contribute to age-related erectile dysfunction (ED). Low-intensity extracorporeal shockwave therapy (Li-ESWT) is a non-invasive intervention for ED, but its effect on penile microvascular function, remains unclear. Our objectives are to (i) evaluate the effect of Li-ESWT (specifically radial type ESWT [rESWT]) on penile microvascular perfusion (PMP) in aging rats, (ii) elucidate a possible mechanism, and (iii) evaluate its impact on angiogenic and smooth muscle biomarkers in cavernosal tissue.
Materials and Methods:
Male rats (n=9; 15–18 months) were anesthetized and subjected to rESWT while monitoring PMP. The nitric oxide (NO) pathway involvement was assessed by measuring the effect of rESWT on PMP following an intracavernosal injection of N(G)-nitroarginine methyl ester (L-NAME) (NO synthase inhibitor). To elucidate the cellular mechanism, another group of rats received repeated rESWT (n=4) or no treatment (n=4) three times/week for two weeks. Rats were euthanized at the end of the study and penile tissues were analyzed for angiogenic markers (vascular endothelial growth factor-A [VEGF-A], endothelial nitric oxide synthase [eNOS]) and smooth muscle content (α-actin) using immunostaining, Western blot, and quantitative polymerase chain reaction (qPCR).
Results:
rESWT resulted in more than a 2-fold increase in PMP (from 68.5 arbitrary units; 163.7 AU). L-NAME injection produced a <40%–50% decrease (185.3 to 101.0 AU) in rESWT-induced PMP response. Immunostaining revealed increased α-actin, eNOS, and VEGF-A in the cavernosum and these findings were confirmed by qPCR and Western blot results.
Conclusions
rESWT improved PMP, which may be mediated via increased VEGF expression, which stimulates the NO/cyclic guanosine monophosphate pathway, resulting in sustained PMP. rESWT devices could offer a safe, non-invasive treatment for age-related ED.
4.Do Strength and Anthropometric Size of the Lower Body Correlate with Serum Testosterone Levels?
Tae Yong PARK ; Moon Young CHOI ; Doohwan KONG ; Jeong Kyun YEO ; Min Gu PARK
The World Journal of Men's Health 2025;43(1):205-212
Purpose:
Although lower body strength and size are often regarded as symbols of masculinity, their relationship to testosterone is unclear. This study aimed to determine the correlation between lower body strength, size, and testosterone levels.
Materials and Methods:
Serum testosterone levels, waist circumference, and body mass index (BMI) were measured in 69 men with erectile dysfunction (age >40 years). The circumferences of the thigh and calf were measured, and the muscle strength of the knee joints was evaluated using an isokinetic dynamometer. Patients were classified into three groups according to testosterone levels (group 1, <230 ng/dL; group 2, 230 to 350 ng/dL; group 3, >350 ng/dL). Differences in calf and thigh circumference, bilateral knee extension, and flexion strength between the three groups were investigated using a one-way analysis of variance. Pearson’s chi-square test was used to assess differences in lifestyle habits and underlying diseases. A partial correlation analysis was conducted to determine the association between testosterone levels and lower body size and strength.
Results:
There was no difference in BMI among the three groups, but waist circumference was significantly larger in group 1 than in groups 2 and 3. When comparing weight-adjusted values, bilateral thigh circumference showed a significant difference among the three groups. There was also a significant difference between the three groups in the weight-adjusted left calf circumference and in the weight-adjusted right knee extension strength. The partial correlation test showed a significant positive correlation between thigh and calf circumference values adjusted for weight and serum testosterone levels. Weight-adjusted knee extension strength demonstrated a significant positive correlation with serum testosterone levels.
Conclusions
Weight-adjusted thigh and calf circumferences, along with the thigh-to-waist ratio, showed a positive correlation with testosterone levels. Weight-adjusted knee extension strength was positively correlated with testosterone levels. Therefore, a robust thigh and strong lower body are related to testosterone.
5.The Application of L-Serine-Incorporated Gelatin Sponge into the Calvarial Defect of the Ovariectomized Rats
Yoon-Jo LEE ; Ji-Hyeon OH ; Suyeon PARK ; Jongho CHOI ; Min-Ho HONG ; HaeYong KWEON ; Weon-Sik CHAE ; Xiangguo CHE ; Je-Yong CHOI ; Seong-Gon KIM
Tissue Engineering and Regenerative Medicine 2025;22(1):91-104
BACKGROUND:
Osteoporosis, characterized by decreased bone mineral density due to an imbalance between osteoblast and osteoclast activity, poses significant challenges in bone healing, particularly in postmenopausal women. Current treatments, such as bisphosphonates, are effective but associated with adverse effects like medication-related osteonecrosis of the jaw, necessitating safer alternatives.
METHODS:
This study investigated the use of L-serine-incorporated gelatin sponges for bone regeneration in calvarial defects in an ovariectomized rat model of osteoporosis. Thirty rats were divided into three groups: a control group, a group treated with a gelatin sponge containing an amino acid mixture, and a group treated with a gelatin sponge containing L-serine. Bone regeneration was assessed using micro-computed tomography (micro-CT) and histological analyses.
RESULTS:
The L-serine group showed a significant increase in bone volume (BV) and bone area compared to the control and amino acid groups. The bone volume to total volume (BV/TV) ratio was also significantly higher in the L-serine group.Immunohistochemical analysis demonstrated that L-serine treatment suppressed the expression of cathepsin K, a marker of osteoclast activity, while increasing serine racemase activity.
CONCLUSION
These findings suggest that L-serine-incorporated gelatin sponges not only enhance bone formation but also inhibit osteoclast-mediated bone resorption, providing a promising and safer alternative to current therapies for osteoporosis-related bone defects. Further research is needed to explore its clinical applications in human patients.
6.Features of Lung Cyst in Birt-Hogg-Dubé Syndrome from Patients with Multiple Lung Cysts
Yong Jun CHOI ; Hye Jung PARK ; Chi Young KIM ; Bo Mi JUNG ; Jae Hwa CHO ; Min Kwang BYUN
Tuberculosis and Respiratory Diseases 2025;88(2):388-398
Background:
High-resolution chest computed tomography (CT) is a crucial assessment tool for diagnosing Birt-Hogg-Dubé (BHD) syndrome. This study aimed to analyze differences of lung cysts between BHD and other cystic lung diseases.
Methods:
From January 2020 to December 2022, patients with multiple lung cysts who underwent chest CT at Gangnam Severance Hospital were included.
Results:
Over a 3-year period (from January 2020 to December 2022), out of 52,823 patients who underwent a chest CT scan, 301 (0.6%) patients with multiple lung cysts were enrolled in this study. Of enrolled patients, 24 (8.0%) were diagnosed with BHD. In patients with BHD, 95.8% exhibited bilateral cysts, and 83.3% showed basal predominance. The cysts’ maximal diameter averaged 32.1 mm (interquartile range, 26.5 to 43.5). Additionally, 95.8% of patients with BHD had diverse cyst sizes and morphologies. Multivariate logistic regression analysis revealed that bilateral cysts (odds ratio [OR], 12.393; 95% confidence interval [CI], 1.613 to 274.682; p=0.038), basal predominance (OR, 8.511; 95% CI, 2.252 to 39.392; p=0.002), maximum diameter (OR, 1.053; 95% CI, 1.009 to 1.108; p=0.032), and diversity of morphology (OR, 19.513; 95% CI, 2.833 to 398.119; p=0.010) were significant factors associated with BHD diagnosis. A multivariate prediction model for BHD diagnosis demonstrated a sensitivity of 95.83%, a specificity of 81.22%, and an area under the receiver operating characteristic curve of 0.951 (95% CI, 0.914 to 0.987).
Conclusion
Distinguishing features of lung cysts from other cystic lung diseases include bilateral cysts, basal dominance, large size, and irregular shape.
7.Pericapsular Nerve Group Block with Periarticular Injection for Pain Management after Total Hip Arthroplasty: A Randomized Controlled Trial
Hun Sik CHO ; Bo Ra LEE ; Hyuck Min KWON ; Jun Young PARK ; Hyeong Won HAM ; Woo-Suk LEE ; Kwan Kyu PARK ; Tae Sung LEE ; Yong Seon CHOI
Yonsei Medical Journal 2025;66(4):233-239
Purpose:
The purpose of this study was to compare the effectiveness of pericapsular nerve group (PENG) block with periarticular multimodal drug injection (PMDI) on postoperative pain management and surgical outcomes in patients who underwent total hip arthroplasty (THA). We hypothesized that PENG block with PMDI would exhibit superior effects on postoperative pain control after THA compared to PMDI alone.
Materials and Methods:
From April 2022 to February 2023, 58 patients who underwent THA were randomly assigned into two groups: PENG block with PMDI group (n=29) and PMDI-only group (n=29). Primary outcomes were postoperative numeric rating scale (NRS) at rest and during activity at 6, 24, and 48 hours postoperatively. Secondary outcomes were postoperative complications (nausea and vomiting), Richards-Campbell Sleep Questionnaire (RCSQ) score, length of hospital stay, Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index, Harris Hip Score (HHS), and total morphine usage after surgery.
Results:
There was no significant difference in postoperative pain for either resting NRS or active NRS. Postoperative nausea and vomiting, RCSQ score, length of hospital stay, WOMAC index, HHS, and total morphine usage exhibited no significant differences between the two groups.
Conclusion
Both groups showed no significant differences in postoperative pain and clinical outcomes, indicating that the addition of PENG block to PMDI does not improve pain management after applying the posterolateral approach of THA. PMDI alone during THA would be an efficient, fast, and safe method for managing postoperative pain. This article was registered with ClinicalTrials.gov (Gov ID: NCT05320913).
8.Adjusted Global Antiphospholipid Syndrome Score Is Associated with End-Stage Kidney Disease in Patients with ANCA-Associated Vasculitis:A Single-Centre Pilot Study
Pil Gyu PARK ; Hyun Joon CHOI ; Yong-Beom PARK ; Sang-Won LEE
Yonsei Medical Journal 2025;66(6):337-345
Purpose:
The adjusted Global Antiphospholipid Syndrome (APS) Score (aGAPSS) was developed for assessing the probability of thrombotic events in APS patients. This study investigated whether the aGAPSS at diagnosis was associated with poor outcomes during follow-up in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).
Materials and Methods:
This study included 170 AAV patients who had the results of APS-related antibodies at diagnosis but were not diagnosed with APS. All-cause mortality, end-stage kidney disease (ESKD), cerebrovascular accident, and acute coronary syndrome were considered poor AAV outcomes. The aGAPSS comprises five items, with 5, 4, 4, 3, and 1 points assigned to anticardiolipin antibodies, anti-β2-glycoprotein 1 antibodies, lupus anticoagulants, hyperlipidaemia, and arterial hypertension at AAV diagnosis, respectively.
Results:
The median age of the 170 patients [93 microscopic polyangiitis (MPA), 44 granulomatosis with polyangiitis (GPA), and 33 eosinophilic GPA (EGPA)] was 63.0 years. The optimal cut-off of the aGAPSS at diagnosis for ESKD during follow-up was set as two using the receiver operating characteristic curve. AAV patients with an aGAPSS ≥2 at diagnosis exhibited a significantly reduced ESKD-free survival rate compared to those with an aGAPSS <2 at diagnosis (p=0.045). Additionally, MPA and GPA patients, excluding EGPA patients for whom the median aGAPSS at diagnosis was close to 0, also showed similar patterns to the results among the 170 patients with AAV (p=0.021).
Conclusion
This study is the first to demonstrate that the aGAPSS at diagnosis was significantly associated with ESKD during follow-up in AAV patients without APS.
9.Development and Application of New Risk-Adjustment Models to Improve the Current Model for Hospital Standardized Mortality Ratio in South Korea
Hyeki PARK ; Ji-Sook CHOI ; Min Sun SHIN ; Soomin KIM ; Hyekyoung KIM ; Nahyeong IM ; Soon Joo PARK ; Donggyo SHIN ; Youngmi SONG ; Yunjung CHO ; Hyunmi JOO ; Hyeryeon HONG ; Yong-Hwa HWANG ; Choon-Seon PARK
Yonsei Medical Journal 2025;66(3):179-186
Purpose:
This study assessed the validity of the hospital standardized mortality ratio (HSMR) risk-adjusted model by comparing models that include clinical information and the current model based on administrative information in South Korea.
Materials and Methods:
The data of 53976 inpatients were analyzed. The current HSMR risk-adjusted model (Model 1) adjusts for sex, age, health coverage, emergency hospitalization status, main diagnosis, surgery status, and Charlson Comorbidity Index (CCI) using administrative data. As candidate variables, among clinical information, the American Society of Anesthesiologists score, Acute Physiology and Chronic Health Evaluation (APACHE) II, Simplified Acute Physiology Score (SAPS) 3, present on admission CCI, and cancer stage were collected. Surgery status, intensive care in the intensive care unit, and CCI were selected as proxy variables among administrative data. In-hospital death was defined as the dependent variable, and a logistic regression analysis was performed. The statistical performance of each model was compared using C-index values.
Results:
There was a strong correlation between variables in the administrative data and those in the medical records. The C-index of the existing model (Model 1) was 0.785; Model 2, which included all clinical data, had a higher C-index of 0.857. In Model 4, in which APACHE II and SAPS 3 were replaced with variables recorded in the administrative data from Model 2, the C-index further increased to 0.863.
Conclusion
The HSMR assessment model improved when clinical data were adjusted. Simultaneously, the validity of the evaluation method could be secured even if some of the clinical information was replaced with the information in the administrative data.
10.Immunologic Response and Effects of COVID-19Vaccines in Patients with Antineutrophil Cytoplasmic Antibody-Associated Vasculitis
Ki Hyun LEE ; Hyunsue DO ; Jun Yong CHOI ; Yong-Beom PARK ; Sinyoung KIM ; Sang-Won LEE ; Su Jin JEONG
Yonsei Medical Journal 2025;66(5):259-268
Purpose:
The immunological response and adverse effects of antineutrophil cytoplasmic antibody-associated vasculitis (AAV) in patients receiving coronavirus disease-2019 (COVID-19) vaccines remain unclear. We aimed to evaluate the effects of these vaccines on AAV disease activity.
Materials and Methods:
We reviewed the medical records of 52 patients with AAV who had received at least second doses of the COVID-19 vaccine and evaluated their immunogenicity by measuring the anti-spike (S) antibody (Ab) titer levels using the Roche Elecsys® immunoassay. Responses to the Birmingham Vasculitis Activity Score (BVAS) tool and 36-Item Short Form Survey before and after vaccination were obtained to assess AAV disease activity. Vaccine reactivity was measured using a standardized questionnaire.
Results:
We enrolled 52 patients with AAV. No differences were found between those who received second and third doses of vaccination in terms of AAV type, disease activity, vaccine type, or the use of immunosuppressive agents, including steroids. The median anti-S Ab titer was 3967.0 after third doses compared to 419.0 after second doses (p=0.001). Except for mycophenolate mofetil (MMF), when immunosuppressants were administered in conjunction with steroids, the Ab titer was higher after the third vaccination than that after the second dose. The BVAS remained unchanged before and after second and third doses. No life-threatening adverse events were reported.
Conclusion
Although COVID-19 vaccine may not produce sufficient antibodies in patients taking MMF, the vaccine did not exacerbate disease activity or cause severe side effects. Therefore, COVID-19 vaccines should be considered in patients with AAV.

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