Background: Long-term use of bisphosphonate is a risk factor for atypical femoral fractures (AFFs). Femoral bowing is known to be associated with AFFs. However, whether femoral bowing quickens the occurrence of AFF is unknown. The purpose of this study was to determine whether AFF occurs earlier in patients with severe femoral bowing than in those without severe bowing. Methods: One hundred and sixty-four patients (186 AFFs) from January 2006 to December 2022 were included in this study.According to severity of femoral bowing, patients were divided into 2 groups: severe bowing group (26 femurs) and minimal to moderate bowing group (160 femurs). Age, sex, and completeness and location of AFF were compared between the 2 groups. We compared the time of AFF occurrence after bisphosphonate therapy using cumulative percentage between the 2 groups. Results: Age and sex were similar between the 2 groups, while body mass index (BMI) was lower (22.5 ± 3.0 kg/m 2 vs. 24.5 ± 3.5 kg/m 2 , p = 0.003) in the severe bowing group. The duration of bisphosphonate use was shorter in the severe bowing group than in the minimal to moderate bowing group (3.3 ± 3.8 years vs. 5.0 ± 4.0 years, p = 0.048). In the severe bowing group, 85% of AFFs were diaphyseal in contrast to the 46% in the minimal to moderate bowing group (p < 0.001). Cumulative percentage plot of AFFs in the severe bowing group was left-shifted compared to the minimal to moderate bowing group. Conclusions At the time of AFF diagnosis, the severe bowing group exhibited shorter duration of bisphosphonate use, lower BMI, and a higher incidence of diaphyseal location. Shortening the duration of bisphosphonate therapy may be advisable in patients with severe femoral bowing.

Background/Aims: The Korean guidelines for Helicobacter pylori treatment were revised in 2020, however, the extent of adherence to these guidelines in clinical practice remains unclear. Herein, we initiated a prospective, nationwide, multicenter registry study in 2021 to evaluate the current management of H.pylori infection in Korea. Methods: This interim report describes the adherence to the revised guidelines and their impact on firstline eradication rates. Data on patient demographics, diagnoses, treatments, and eradication outcomes were collected using a web-based electronic case report form. Results: A total of 7,261 patients from 66 hospitals who received first-line treatment were analyzed.The modified intention-to-treat eradication rate for first-line treatment was 81.0%, with 80.4% of the prescriptions adhering to the revised guidelines. The most commonly prescribed regimen was the 14-day clarithromycin-based triple therapy (CTT; 42.0%), followed by tailored therapy (TT; 21.2%), 7-day CTT (14.1%), and 10-day concomitant therapy (CT; 10.1%). Time-trend analysis demonstrated significant increases in guideline adherence and the use of 10-day CT and TT, along with a decrease in the use of 7-day CTT (all p<0.001). Multivariate logistic regression analysis revealed that guideline adherence was significantly associated with first-line eradication success (odds ratio, 2.03; 95% confidence interval, 1.61 to 2.56; p<0.001). Conclusions The revised guidelines for the treatment of H. pylori infection have been increasingly adopted in routine clinical practice in Korea, which may have contributed to improved first-line eradication rates. Notably, the 14-day CTT, 10-day CT, and TT regimens are emerging as the preferred first-line treatment options among Korean physicians.

Background/Aims: Infliximab treatment failure in patients with inflammatory bowel disease may result from sub-optimal infliximab trough level. An understanding of pharmacokinetics (PKs) is important to maintain an optimal trough level. PK studies of the switch to subcutaneous (SC) infliximab from intravenous (IV) infliximab using real-world data are lacking. We aimed to develop a population PK model of IV and SC infliximab to predict individual infliximab exposure during maintenance therapy. Methods: We used data from prospectively collected data on IV and SC infliximab concentrations in patients with inflammatory bowel disease receiving maintenance treatment from February 2020 to December 2022 at Samsung Medical Center. Population PK analysis was conducted by using a two-compartment model with first-order absorption and first-order elimination. Goodness-of-fit plots and visual predictive check were used to evaluate the PK model. Results: A total of 2,132 samples from 181 patients (149 Crohn’s disease and 32 ulcerative colitis) were analyzed. We developed an infliximab population PK model using body mass index, albumin, C-reactive protein level, and the anti-drug antibody level and validated its predictive performance. Conclusions It may be possible to predict the infliximab trough level of both IV and SC infliximab in patients with inflammatory bowel disease during maintenance treatment by using our model in real-world practice.

Background and Objectives: Hearing loss significantly affects communication, psychosocial well-being, and quality of life. This study analyzes the National Health Insurance Service database to assess the trends and characteristics of hearing loss in South Korea from 2010 to 2020.Subjects and Method The database encompasses 97% of the Korean population, providing comprehensive data on medical history, prescriptions, and health examinations. The analysis used the World Health Organization’s ICD-10 definitions to categorize hearing loss types and examine their prevalence and incidence across various demographics over 11 years. Results: There was an overall annual increase of 4.62% in diagnosed cases of hearing loss, with the most significant rise among the elderly. The rate of increase accelerated from 3.32% between 2010 and 2014 to 6.49% between 2014 and 2020, corresponding with the improved hearing aid access facilitated by policy changes. Women showed a slightly higher increase than men. The data also indicated a consistent rise in abnormal hearing test results during health examinations, especially in older adults. Conclusion The study highlights an increasing trend in hearing loss diagnoses, driven by an aging population and enhanced detection facilitated by policy changes. These findings emphasize the need for continuous monitoring and targeted health policies to manage hearing loss effectively, offering valuable insights for global health management and policy development.

Background and Objectives: This study aims to analyze trends in hearing disability and the use of hearing rehabilitation devices (hearing aids and cochlear implants) in South Korea over the past 11 years (2010-2020) using data from the National Health Insurance Service (NHIS).Subjects and Method Data were extracted from the NHIS database, covering approximately 97% of the South Korean population. Patients diagnosed with hearing loss were classified using ICD-10 codes. The data were analyzed to determine trends in hearing disability, hearing aid prescriptions, and cochlear implant usage by age, gender, and types and causes of hearing loss. Results: The number of hearing disability patients increased from 170900 in 2010 to 362738 in 2020, with an annual growth rate of 7.95%. The highest increase was observed in the ≥60 age group, with an annual growth rate of 11.04%. Hearing aid prescriptions rose from 4966 in 2010 to 11974 in 2020, showing a 10.45% annual increase. Females showed a higher growth rate in both hearing disability and hearing aid prescriptions compared to males. Cochlear implant prescriptions also increased, particularly among older adults. Conclusion The study highlights a significant rise in hearing disability and the use of hearing aids and cochlear implants in South Korea, especially among the elderly. The findings underscore the importance of early diagnosis and intervention for hearing loss and the need for policy improvements to enhance accessibility and affordability of hearing rehabilitation services. Additional strategies are needed to ensure appropriate hearing rehabilitation for those not yet receiving adequate care.

The anticancer drugs have evolved significantly, spanning molecular targeted therapeutics (MTTs), immune checkpoint inhibitors (ICIs), chimeric antigen receptor T-cell (CAR-T) therapy, and antibody-drug conjugates (ADCs). Complications associated with these drugs vary widely based on their mechanisms of action. MTTs that target angiogenesis can often lead to complications related to ischemia or endothelial damage across various organs, whereas non-anti-angiogenic MTTs present unique complications derived from their specific pharmacological actions. ICIs are predominantly associated with immunerelated adverse events, such as pneumonitis, colitis, hepatitis, thyroid disorders, hypophysitis, and sarcoid-like reactions. CAR-T therapy causes unique and severe complications including cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome. ADCs tend to cause complications associated with cytotoxic payloads. A comprehensive understanding of these drug-specific toxicities, particularly using medical imaging, is essential for providing optimal patient care. Based on this knowledge, radiologists can play a pivotal role in multidisciplinary teams. Therefore, radiologists must stay up-to-date on the imaging characteristics of these complications and the mechanisms underlying novel anticancer drugs.

Objective: This study aimed to investigate the prevalence and characteristics of impacted teeth (ITs) in orthodontic patients at university dental hospitals in Korea. Methods: This study included 14,774 patients who visited the Department of Orthodontics at 10 university dental hospitals in Korea between 2020 and 2022 and underwent orthodontic diagnosis. The prevalence and characteristics of ITs were investigated using orthodontic diagnostic records, radiographs, and diagnostic casts. Results: The prevalence of ITs, excluding third molar impaction, in Korean orthodontic patients was 13.6% (n = 2,014).The prevalence of ITs in pediatric orthodontic patients was 24.5% (n = 1,614).Of these patients, 68.2% had one IT, 27.5% had two ITs, 24.3% had bilateral IT, and 75.7% had unilateral IT. The most frequent IT was the maxillary canine (50.1%), followed by the mandibular second molar (11.7%), and maxillary second premolar (9.6%). An abnormal eruption path (46.5%) was the most frequent etiology. Orthodontic traction after surgical exposure (70.6%) was the most frequent treatment option. Among the patients with ITs, 29.8% had other dental anomalies, such as tooth agenesis (8.7%), microdontia (8.0%), and supernumerary teeth (5.1%). Furthermore, 50.8% had complications such as cystic lesions (18.3%), transposition (17.7%), and root resorption (14.8%).Among the patients with maxillary canine impaction, 62.2% had labial maxillary canine impaction and 21.1% had palatal maxillary canine impaction. Conclusions The prevalence of ITs in Korean orthodontic patients at university dental hospitals was high, particularly in pediatric orthodontic patients.

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.

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.

Background: This study aimed to determine whether a shorter high-dose rifampicin regimen is non-inferior to the standard 6-month tuberculosis regimen. Methods: This multicenter, randomized, open-label, non-inferiority trial enrolled participants with respiratory specimen positivity by Xpert MTB/RIF assay or Mycobacterium tuberculosis culture without rifampicin-resistance. Participants were randomized at 1:1 to the investigational or control group. The investigational group received high-dose rifampicin (30 mg/kg/day), isoniazid, and pyrazinamide until culture conversion, followed by high-dose rifampicin and isoniazid for 12 weeks. The control group received the standard 6-month regimen. The primary outcome was the rate of unfavorable outcomes at 18 months post-randomization. The non-inferiority margin was set at <6% difference in unfavorable outcomes rates. The study is registered with ClinicalTrials.gov (NCT04485156) Results: Between 4 November 2020 and 3 January 2022, 76 participants were enrolled. Of these, 58 were included in the modified intention-to-treat analysis. Unfavorable outcomes occurred in 10 (31.3%) of 32 in the control group and 10 (38.5%) of 26 in the investigational group. The difference was 7.2% (95% confidence interval, ∞ to 31.9%), failing to prove non-inferiority. Serious adverse events and grade 3 or higher adverse events did not differ between the groups. Conclusion The shorter high-dose rifampicin regimen failed to demonstrate non-inferiority but had an acceptable safety profile.