Dental implants are accepted as an effective treatment tools; however, they have a biomechanically disadvantageous structure compared with natural teeth. To compensate for the structural limitations of dental implants, occlusal must be considered to minimize the stress applied to the implants. This study aimed to verify whether the basic biomechanical principle that stress should be applied along the long axis of the implant fixture could be appropriately applied to actual implant clinical treatment. To evaluate whether the major axis of the implant is located at the center of the occlusion surface, the location of the screw hole was analyzed using the image of the stereolithographic file formed during the digital laboratory process, and the accuracy of implant placement was confirmed indirectly.The study included 261 patients and 392 implant cases. By tooth type, the numbers of samples were 57 in the first premolar, 66 in the second premolar, 152 in the first molar, and 117 in the second molar. The location of the screw hole was analyzed by dividing the occlusion surface of the implant crown into nine grids of the same size based on the outermost boundary. Consequently, the accuracy of implant placement tended to decrease from the premolar to the molar, upper jaw to the lower jaw, and left to right.

Purpose: To determine subjective symptoms and medical history of patients with intermittent exotropia in a large study population. Methods: The Korean Intermittent Exotropia Multicenter Study (KIEMS) is a nationwide, observational, cross-sectional, multicenter study conducted by the Korean Association for Pediatric Ophthalmology and Strabismus including 5,385 patients with intermittent exotropia. Subjective symptoms and medical history of patients with intermittent exotropia were extracted by a comprehensive survey based on a self-administered questionnaire according to the study protocol of the KIEMS. Results: The mean age of symptom onset was 5.5 years. The most common symptom reported in patients with intermittent exotropia was photophobia (52.1%), followed by diplopia at near fixation (7.3%) and distance fixation (6.2%). Preterm birth was found in 8.8%, and 4.1% had perinatal complications. A family history of strabismus was present in 14.9%, and 5.5% of patients had a family member who underwent strabismus surgery. Conclusions The KIEMS is one of the largest clinical studies on intermittent exotropia. Intermittent exotropia frequently caused photophobia and diplopia, and patients with a family history was not uncommon.

Background and Objectives: The colonic epithelial layer is a complex structure consisting of multiple cell types that regulate various aspects of colonic physiology, yet the mechanisms underlying epithelial cell differentiation during development remain unclear. Organoids have emerged as a promising model for investigating organogenesis, but achieving organ-like cell configurations within colonic organoids is challenging. Here, we investigated the biological significance of peripheral neurons in the formation of colonic organoids. Methods: and Results: Colonic organoids were co-cultured with human embryonic stem cell (hESC)-derived peripheralneurons, resulting in the morphological maturation of columnar epithelial cells, as well as the presence of enterochromaffin cells. Substance P released from immature peripheral neurons played a critical role in the development of colonic epithelial cells. These findings highlight the vital role of inter-organ interactions in organoid development and provide insights into colonic epithelial cell differentiation mechanisms. Conclusions Our results suggest that the peripheral nervous system may have a significant role in the development ofcolonic epithelial cells, which could have important implications for future studies of organogenesis and disease modeling.

Objectives: The purpose of this study was to compare the fracture strength and traslucency of 3D printing resin crowns according to different thicknesses. Methods: Resin crowns were designed with CAD software and a 3D scanner, using scanned data of the #61 tooth model. Resin Crowns with different thicknesses were printed using a 3D printer, and subsequently divided into four groups according to thickness (0.3, 0.5, 0.7, and 1.0 mm). Fracture strength was compared among groups with a resin strip crown of 1.0 mm thickness. Compressive force was applied using a universal testing machine at 30° along the lingual surface at 1 mm/min cross head speed. For translucency evaluation, thin square specimens were printed of thicknesses 0.3, 0.5, 0.7, and 1.0 mm, and translucency was measured using a spectrophotometer. Results: As a result of fracture strength measurement, fracture strength increased as thickness increased, and a significant difference was observed solely between thicknesses of 0.3 and 0.5 mm, and the thicknesses of 0.3 and 0.5 mm (P<0.05). Translucency decreased as thickness increased, and similarly, a significant difference was observed only between thicknesses of 0.3 and 0.5 mm and the thicknesses of 0.7 and 1.0 mm (P<0.05). Conclusions A 3D printing resin crown can be used as a clinical option for restoring a primary anterior tooth affected by caries.

Background: Large-scale studies about epidemiologic characteristics of renal infarction (RI) are few. In this study, we aimed to analyze the incidence and prevalence of RI with comorbidities in the South Korean population. Methods: We investigated the medical history of the entire South Korean adult population between 2013 and 2019 using the National Health Insurance Service database (n = 51,849,591 in 2019). Diagnosis of RI comorbidities were confirmed with International Classification of Disease, Tenth Revision, Clinical Modification codes. Epidemiologic characteristics, distribution of comorbidities according to etiologic mechanisms, and trend of antithrombotic agents were estimated. Results: During the 7-years, 10,496 patients were newly diagnosed with RI. The incidence rate increased from 2.68 to 3.06 per 100,000 person-years during the study period.The incidence rate of RI increased with age peaking in the 70s with 1.41 times male predominance. The most common comorbidity was hypertension, followed by dyslipidemia and diabetes mellitus. Regarding etiologic risk factor distribution, high embolic risk group, renovascular disease group, and hypercoagulable state group accounted for 16.6%, 29.1%, and 13.7% on average, respectively. For the antithrombotic treatment of RI, the prescription of antiplatelet agent gradually decreased from 17.0% to 13.0% while that of anticoagulation agent was maintained around 35%. The proportion of non-vitamin K antagonist oral anticoagulants remarkably increased from only 1.4% to 17.6%. Conclusion Considering the progressively increasing incidence of RI and high prevalence of coexisting risk factors, constant efforts to raise awareness of the disease are necessary. The current epidemiologic investigation of RI would be the stepping-stone to establishing future studies about clinical outcomes and optimal treatment strategies.

Objectives: This study aimed to evaluate the effectiveness of the Jeollabuk-do Suicide Prevention Training Program for professional gatekeeper instructors, using psychological questionnaires. Methods: Eighty-three participants were recruited from mental health centers and relevant organizations in Jeollabuk-do. All the participants were randomly assigned to either an experimental group (n=41), where they took part in the suicide prevention training program developed by Jeollabuk-do for professional gatekeeper instructors, or a control group (n=42), receiving no treatment. Four participants from the control group dropped out, and the final participants for each group were 41 and 38. We analyzed the changes in the two groups, before and after the program, using the Korean Suicide Literacy Scale, Counselors’ Professional Scale for Self-injury Behaviors, Attitudes towards the Suicide Scale, and Help-Giving. Results: Participants in the experimental group exhibited a significant improvement in their knowledge of suicide prevention and their attitude toward suicide compared to those in the control group. Conclusion This study suggests that the Jeollabuk-do Suicide Prevention Training Program for professional gatekeeper instructors may serve as an effective means of improving the participant’s knowledge of suicide prevention and changing the attitude towards suicide, and may fulfill its purpose of preventing suicides.

Objective: Dysphagia is a common clinical condition characterized by difficulty in swallowing. It is sub-classified into oropharyngeal dysphagia, which refers to problems in the mouth and pharynx, and esophageal dysphagia, which refers to problems in the esophageal body and esophagogastric junction. Dysphagia can have a significant negative impact one’s physical health and quality of life as its severity increases. Therefore, proper assessment and management of dysphagia are critical for improving swallowing function and preventing complications. Thus a guideline was developed to provide evidence-based recommendations for assessment and management in patients with dysphagia. Methods: Nineteen key questions on dysphagia were developed. These questions dealt with various aspects of problems related to dysphagia, including assessment, management, and complications. A literature search for relevant articles was conducted using Pubmed, Embase, the Cochrane Library, and one domestic database of KoreaMed, until April 2021. The level of evidence and recommendation grade were established according to the Grading of Recommendation Assessment, Development and Evaluation methodology. Results: Early screening and assessment of videofluoroscopic swallowing were recommended for assessing the presence of dysphagia. Therapeutic methods, such as tongue and pharyngeal muscle strengthening exercises and neuromuscular electrical stimulation with swallowing therapy, were effective in improving swallowing function and quality of life in patients with dysphagia. Nutritional intervention and an oral care program were also recommended. Conclusion This guideline presents recommendations for the assessment and management of patients with oropharyngeal dysphagia, including rehabilitative strategies.

Background/Aims: We aimed to analyze the efficacy of angiotensin receptor-neprilysin inhibitor (ARNI) by the disease course of heart failure (HF). Methods: We evaluated 227 patients with HF in a multi-center retrospective cohort that included those with left ventricular ejection fraction (LVEF) ≤ 40% undergoing ARNI treatment. The patients were divided into patients with newly diagnosed HF with ARNI treatment initiated within 6 months of diagnosis (de novo HF group) and those who were diagnosed or admitted for HF exacerbation for more than 6 months prior to initiation of ARNI treatment (prior HF group). The primary outcome was a composite of cardiovascular death and worsening HF, including hospitalization or an emergency visit for HF aggravation within 12 months. Results: No significant differences in baseline characteristics were reported between the de novo and prior HF groups. The prior HF group was significantly associated with a higher primary outcome (23.9 vs. 9.4%) than the de novo HF group (adjusted hazard ratio 2.52, 95% confidence interval 1.06–5.96, p = 0.036), although on a higher initial dose. The de novo HF group showed better LVEF improvement after 1 year (12.0% vs 7.4%, p = 0.010). Further, the discontinuation rate of diuretics after 1 year was numerically higher in the de novo group than the prior HF group (34.4 vs 18.5%, p = 0.064). Conclusions The de novo HF group had a lower risk of the primary composite outcome than the prior HF group in patients with reduced ejection fraction who were treated with ARNI.

Purpose: Since tumor mutational burden (TMB) and gene expression profiling (GEP) have complementary effects, they may have improved predictive power when used in combination. Here, we investigated the ability of TMB and GEP to predict the immunotherapy response in patients with non–small cell lung cancer (NSCLC) and assessed if this combination can improve predictive power compared to that when used individually. Materials and Methods: This retrospective cohort study included 30 patients with NSCLC who received immune checkpoint inhibitors (ICI) therapy at the Seoul National University Bundang Hospital. programmed cell death-ligand-1 (PD-L1) protein expression was assessed using immunohistochemistry, and TMB was measured by targeted deep sequencing. Gene expression was determined using NanoString nCounter analysis for the PanCancer IO360 panel, and enrichment analysis were performed. Results: Eleven patients (36.7%) showed a durable clinical benefit (DCB), whereas 19 (63.3%) showed no durable benefit (NDB). TMB and enrichment scores (ES) showed significant differences between the DCB and NDB groups (p=0.044 and p=0.017, respectively); however, no significant correlations were observed among TMB, ES, and PD-L1. ES was the best single biomarker for predicting DCB (area under the curve [AUC], 0.794), followed by TMB (AUC, 0.679) and PD-L1 (AUC, 0.622). TMB and ES showed the highest AUC (0.837) among other combinations (AUC [TMB and PD-L1], 0.777; AUC [PD-L1 and ES], 0.763) and was similar to that of all biomarkers used together (0.832). Conclusion The combination of TMB and ES may be an effective predictive tool to identify patients with NSCLC patients who would possibly benefit from ICI therapies.