This review examines the challenges associated with occupational disease surveillance in Korea, particularly emphasizing the limitations of current data sources such as the Industrial Accident Compensation Insurance (IACI) statistics and special health examinations. The IACI system undercounts cases due to its emphasis on severe diseases and restrictions on approvals. Special health examinations, although they cover a broad workforce, are constrained by their annual scheduling, which leads to missed acute illnesses and subclinical conditions. The paper also explores the history of occupational disease surveillance in Korea, highlighting the fragmented and disease-specific approach of earlier systems. The authors introduce the newly established Korea Occupational Disease Surveillance Center (KODSC), a comprehensive nationwide system designed to gather, analyze, and interpret data on occupational diseases through a network of regional centers. By incorporating hospital-based surveillance and focusing on acute poisonings and other sentinel events, the KODSC aims to overcome the limitations of previous systems and promote collaboration with various agencies. Although it is still in the early stages of implementation, the KODSC demonstrates potential for improving data accuracy and contributing valuable insights for public health policy.

Background/Aims: Krebs von den Lungen-6 (KL-6) is associated with prognosis in patients with COVID-19. However, there is limited data on the correlation between the prognosis of COVID-19 and varying KL-6 levels at different time points. We investigated the optimal cutoff values of the initial and peak serum KL-6 levels to predict mortality and evaluated their correlation with mortality. Methods: This retrospective cohort study collected data on serially collected serum KL-6 levels in patients hospitalized with COVID-19 between October 2020 and January 2022 at a single tertiary hospital in South Korea. The area under the receiver operating characteristic curve and Youden index were used to determine the cutoff points for the initial and peak KL-6 levels that best predicted 30-day mortality. The association between the initial and peak KL-6 values was assessed by univariate and multivariate logistic regression models. Results: A total of 349 patients were included in this study. The mean initial and peak KL-6 levels were significantly higher in the non-survivor group than in the survivor group. The initial and peak KL-6 values that best predicted 30-day mortality were 491.85 U/mL and 660.05 U/mL, respectively. An initial KL-6 level greater than 491.85 U/mL and a peak KL-6 level greater than 660.05 U/mL were significantly associated with 30-day mortality. Conclusions The initial and peak levels of KL-6 were significantly associated with 30-day mortality in hospitalized patients with COVID-19. These findings suggest that serially monitoring blood KL-6 levels could be a valuable prognostic indicator for COVID-19.

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.

Background: Small cell lung cancer (SCLC) is called ‘smoker’s disease’ because it is strongly associated with smoking and most cases occur in smokers. However, it can also occur in never smokers. We investigated the clinical features of never smokers with SCLC and compared their treatment outcomes with those of smokers with SCLC. Methods: We retrospectively reviewed the clinical data of patients who had proven SCLC and had received chemotherapy at a single cancer center between July 2002 and April 2021. Results: Of 1,643 patients, 1,416 (86.2%) were enrolled in this study. A total of 162 (11.4%) and 1,254 (88.6%) patients were never smokers and smokers, respectively. There were more female never smokers than smokers (n=130; 80.2% vs. 79, 6.3%, p=0.000), and the incidence of ischemic heart disease was lower among never smokers than among smokers (4/1,416, [2.5%] vs. 83/1,416 [6.6%], p=0.036). Never smokers showed less symptoms at diagnosis than smokers (80.9% vs. 87.2%, p=0.037); however, they showed more toxicity after first-line treatment (61.7% vs. 47.8%, p=0.001). The objective response rate (ORR) was significantly higher in never smokers (74.1% vs. 59.6%, p=0.000). In the multivariate analysis, never smoking and second-line treatment were associated with a better ORR. However, progression-free survival and overall survival were not significantly different between never smokers and smokers. Conclusion In conclusion, never smokers accounted for 11.4% of patients with SCLC. They had distinguishing clinical characteristics and showed better chemotherapeutic responses than smokers.

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.

Purpose: We assessed human papillomavirus (HPV) genotype-based risk stratification and the efficacy of cytology testing for cervical cancer screening in patients with atypical squamous cells of undetermined significance (ASCUS)/low-grade squamous intraepithelial lesion (LSIL). Materials and Methods: Between 2010 and 2021, we monitored 1,273 HPV-positive women with ASCUS/LSIL every 6 months for up to 60 months. HPV infections were categorized as persistent (HPV positivity consistently observed post-enrollment), negative (HPV negativity consistently observed post-enrollment), or non-persistent (neither consistently positive nor negative). HPV genotypes were grouped into high-risk (Hr) groups 1 (types 16, 18, 31, 33, 45, 52, and 58) and 2 (types 35, 39, 51, 56, 59, 66, and 68) and a low-risk group. Hr1 was subdivided into types (a) 16 and 18; (b) 31, 33, and 45; and (c) 52 and 58. Cox regression and machine learning (ML) algorithms were used to analyze progression rates. Results: Among 1,273 participants, 17.6% with persistent HPV infections experienced disease progression versus no progression in the HPV-negative group (p < 0.001). Cox analysis revealed the highest hazard ratios (HRs) for Hr1-a (11.6, p < 0.001), followed by Hr1-b (9.26, p < 0.001) and Hr1-c (7.21, p < 0.001). HRs peaked at 12-24 months, with Hr1-a maintaining significance at 24-36 months (10.7, p=0.034). ML analysis identified the final cytology change pattern as the most significant factor, with 14-15 months the optimal time for detecting progression from the first examination. Conclusion In ASCUS/LSIL cases, follow-up strategies should be based on HPV risk types. Annual follow-up was the most effective monitoring for detecting progression/regression.

Background: Enchondroma is a common benign bone tumor in the hand, often leading to delayed diagnosis due to its asymptomatic nature. The surgical treatment strategy for enchondroma, particularly in pathologic fractures, remains unclear. This study aimed to evaluate the outcomes of treatment for non- or minimally displaced pathologic fractures in enchondroma using autogenous bone grafts alone, without metal fixation. Methods: A retrospective analysis was conducted on 34 patients who underwent surgery for enchondroma and pathologic fractures. Clinical and radiographic outcomes were assessed, including pain scores, range of motion (ROM), Disabilities of the Arm, Shoulder, and Hand (DASH) score, grip strength, fracture union time, and complications. Results: All patients reported pain at the fracture site preoperatively. The preoperative pain visual analog scale (VAS) score was 4.5.Postoperatively, the pain VAS score improved significantly to 2.3. The postoperative average total ROM was 253.8°. The average DASH score was 5.1, and grip strength was 97.8% compared to the unaffected side. Bony union was achieved in all cases with an average union time of 10.9 weeks. No complications were observed except for 1 suspected recurrence. Conclusions Early single-stage surgical treatment with curettage and autogenous bone grafts without fixation yielded satisfactory results for non- or minimally displaced pathologic fractures in enchondroma. This non-fixative technique offers a viable option with reduced treatment duration and implant-related complications.

Background: The management of distal radius fractures (DRFs) has evolved with the introduction of volar locking plate (VLP) fixation.Nevertheless, despite the low occurrence rates, reduction loss following VLP fixation has been reported in several studies. Our objective was to determine the incidence and features of reduction loss in patients despite the appropriate application of VLP fixation for DRF. Methods: This retrospective study was conducted between March 2017 and August 2023, during which a single hand surgeon performed VLP procedures for DRFs. This study included 379 patients (382 wrists) including 3 patients who underwent bilateral surgery. We identified patients who experienced reduction loss after VLP fixation (group 1) and patients without stability problems (group 2) and compared the 2 groups. Results: The mean age of the patients was 63.5 years, with a standard deviation of 13.8. There were 90 male patients (23.6%) and 289 female patients (75.7%). We identified 14 cases of DRFs, in which reduction loss occurred even after VLP fixation during the follow-up period (group 1, 3.7%). The remaining DRFs were assigned to group 2 (n=368, 96.3%). Among the 14 patients, 7 cases of screw breakage were identified as causing the loss of fracture reduction. As the joint surface collapsed and sank down to the distal row locking screw, 4 cases presented with distal locking screws penetrating into the radiocarpal joint. There were no significant differences between the 2 groups in terms of sex, weight, fracture arm direction, and Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) fracture classification. However, patients in group 1 were statistically significantly older than those in group 2 (average age, 77.5 years vs. 62 years). Among 4 patients experiencing distal screw violation of the radiocarpal joints, 3 underwent partial or complete screw removal immediately after fracture consolidation or union. Conclusions While rare, reduction loss remains a potential complication following VLP fixation, especially in elderly patients with intra-articular DRFs. However, with diligent monitoring and timely intervention, such as implant removal if necessary, acceptable outcomes can still be attained.

Background: Studies comparing the minimally invasive proximal chevron and Akin osteotomies (MIPCA) technique with conventional techniques, such as the open proximal chevron metatarsal osteotomy with the Akin procedure (open PCMO-Akin procedure), are limited. This study aimed to compare and evaluate operative MIPCA and open PCMO-Akin procedure outcomes in the surgical correction of moderate-to-severe hallux valgus deformities. Methods: We conducted a retrospective comparison of clinical and radiographic outcomes between the MIPCA and open PCMOAkin procedure in patients with a hallux valgus deformity, defined as a preoperative hallux valgus angle (HVA) of ≥ 30° and/or a first to second intermetatarsal angle of ≥ 13°. The postoperative complication rate was monitored in both groups for a minimum of 12 months. An unsatisfactory correction was defined as an HVA > 15° at final follow-up. Results: We assigned 58 and 99 patients to the MIPCA or open PCMO-Akin procedure group, respectively. At final follow-up, no significant differences were observed between the groups in terms of clinical and radiographic parameters (p > 0.05), with the exception of the distal metatarsal articular angle (DMAA) (p = 0.012). No statistically significant postoperative changes in the DMAA were observed in the MIPCA group (p = 0.875). Five patients (5.1%) experienced postoperative hallux varus in the open PCMO-Akin procedure group, whereas no such cases were observed in the MIPCA group. No statistically significant difference in the rate of unsatisfactory correction was observed between the groups at the final follow-up (MIPCA group, 15.5%; open PCMO-Akin procedure group, 10.1%; p = 0.315). Conclusions The MIPCA technique is a viable alternative to the open PCMO-Akin procedure for correcting moderate-to-severe hallux valgus deformities. Given the potential lack of postoperative changes in the DMAA following the MIPCA technique, careful consideration is advised when applying this technique to patients with a large DMAA.