Purpose: The aim of this study was to determine which scan range would provide the most accurate bite registration when perform-ing a bite scan after scanning an upper and lower arch using an intraoral scanner. Materials and Methods: The occlusal contact points were recorded using articulating paper for 30 adults, and the results of various ranges of buccal bite scan were compared based on this. Buccal bite scan of 5 ranges (1st premolar to 2nd premolar, 1st premolar to 1st molar, 1st premolar to 2nd molar, 2nd premolar to 1st molar, and canines to another side canine of the maxillary teeth) was performed, and then the buccal bite scan file was used in a CAD program to confirm the occlusal area in the scan file through data editing and alignment, leaving the buccal area of the teeth. Afterwards, the degree of agreement between the occlusal contact points obtained from the articulating paper and the occlusal area obtained from the scan file was compared, and statistical analysis was performed using the homoscedastic Ttest (α = 0.05). Results: The alignment success and alignment failure rates among each group were 77.23% and 40.85% in canine to another side canine, 68.23% and 28.89% in bilateral first premolar to second premolar, 63.76% and 29.97% in bilateral first premolar to first molar, 61.31% and 32.04% in bilateral first premolar to second molar, 67.55% and 27.46% in second premolar to first molar.The results of the anterior scan of both canines showed higher alignment success and failure rates compared to the scan results ofall maxillary posterior teeth. In the alignment success rate, statistical significance was not found depending on the scan range of the posterior teeth, but in comparing the results of the posterior teeth and both canines, statistical significance was observed except for the scan results of the second premolar to the first molar. There was no statistical significance in the alignment failure rate depend-ing on the scan range of the posterior teeth, and statistical significance was observed in the results of the posterior teeth and bothcanines. Conclusion When taking a buccal bite scan, in the case of scanning the anterior teeth, more occlusal area appear than when scanning the posterior teeth, and in the case of scanning the posterior teeth, there is no significant difference in the bite reg-istration depending on the scan range.

Purpose: The aim of this study was to determine which scan range would provide the most accurate bite registration when perform-ing a bite scan after scanning an upper and lower arch using an intraoral scanner. Materials and Methods: The occlusal contact points were recorded using articulating paper for 30 adults, and the results of various ranges of buccal bite scan were compared based on this. Buccal bite scan of 5 ranges (1st premolar to 2nd premolar, 1st premolar to 1st molar, 1st premolar to 2nd molar, 2nd premolar to 1st molar, and canines to another side canine of the maxillary teeth) was performed, and then the buccal bite scan file was used in a CAD program to confirm the occlusal area in the scan file through data editing and alignment, leaving the buccal area of the teeth. Afterwards, the degree of agreement between the occlusal contact points obtained from the articulating paper and the occlusal area obtained from the scan file was compared, and statistical analysis was performed using the homoscedastic Ttest (α = 0.05). Results: The alignment success and alignment failure rates among each group were 77.23% and 40.85% in canine to another side canine, 68.23% and 28.89% in bilateral first premolar to second premolar, 63.76% and 29.97% in bilateral first premolar to first molar, 61.31% and 32.04% in bilateral first premolar to second molar, 67.55% and 27.46% in second premolar to first molar.The results of the anterior scan of both canines showed higher alignment success and failure rates compared to the scan results ofall maxillary posterior teeth. In the alignment success rate, statistical significance was not found depending on the scan range of the posterior teeth, but in comparing the results of the posterior teeth and both canines, statistical significance was observed except for the scan results of the second premolar to the first molar. There was no statistical significance in the alignment failure rate depend-ing on the scan range of the posterior teeth, and statistical significance was observed in the results of the posterior teeth and bothcanines. Conclusion When taking a buccal bite scan, in the case of scanning the anterior teeth, more occlusal area appear than when scanning the posterior teeth, and in the case of scanning the posterior teeth, there is no significant difference in the bite reg-istration depending on the scan range.

Purpose: The aim of this study was to determine which scan range would provide the most accurate bite registration when perform-ing a bite scan after scanning an upper and lower arch using an intraoral scanner. Materials and Methods: The occlusal contact points were recorded using articulating paper for 30 adults, and the results of various ranges of buccal bite scan were compared based on this. Buccal bite scan of 5 ranges (1st premolar to 2nd premolar, 1st premolar to 1st molar, 1st premolar to 2nd molar, 2nd premolar to 1st molar, and canines to another side canine of the maxillary teeth) was performed, and then the buccal bite scan file was used in a CAD program to confirm the occlusal area in the scan file through data editing and alignment, leaving the buccal area of the teeth. Afterwards, the degree of agreement between the occlusal contact points obtained from the articulating paper and the occlusal area obtained from the scan file was compared, and statistical analysis was performed using the homoscedastic Ttest (α = 0.05). Results: The alignment success and alignment failure rates among each group were 77.23% and 40.85% in canine to another side canine, 68.23% and 28.89% in bilateral first premolar to second premolar, 63.76% and 29.97% in bilateral first premolar to first molar, 61.31% and 32.04% in bilateral first premolar to second molar, 67.55% and 27.46% in second premolar to first molar.The results of the anterior scan of both canines showed higher alignment success and failure rates compared to the scan results ofall maxillary posterior teeth. In the alignment success rate, statistical significance was not found depending on the scan range of the posterior teeth, but in comparing the results of the posterior teeth and both canines, statistical significance was observed except for the scan results of the second premolar to the first molar. There was no statistical significance in the alignment failure rate depend-ing on the scan range of the posterior teeth, and statistical significance was observed in the results of the posterior teeth and bothcanines. Conclusion When taking a buccal bite scan, in the case of scanning the anterior teeth, more occlusal area appear than when scanning the posterior teeth, and in the case of scanning the posterior teeth, there is no significant difference in the bite reg-istration depending on the scan range.

Background/Aims: Shifts in the gut microbiota and metabolites are interrelated with liver cirrhosis progression and complications. However, causal relationships have not been evaluated comprehensively. Here, we identified complication-dependent gut microbiota and metabolic signatures in patients with liver cirrhosis. Methods: Microbiome taxonomic profiling was performed on 194 stool samples (52 controls and 142 cirrhosis patients) via V3-V4 16S rRNA sequencing. Next, 51 samples (17 controls and 34 cirrhosis patients) were selected for fecal metabolite profiling via gas chromatography mass spectrometry and liquid chromatography coupled to timeof-flight mass spectrometry. Correlation analyses were performed targeting the gut-microbiota, metabolites, clinical parameters, and presence of complications (varices, ascites, peritonitis, encephalopathy, hepatorenal syndrome, hepatocellular carcinoma, and deceased). Results: Veillonella bacteria, Ruminococcus gnavus, and Streptococcus pneumoniae are cirrhosis-related microbiotas compared with control group. Bacteroides ovatus, Clostridium symbiosum, Emergencia timonensis, Fusobacterium varium, and Hungatella_uc were associated with complications in the cirrhosis group. The areas under the receiver operating characteristic curve (AUROCs) for the diagnosis of cirrhosis, encephalopathy, hepatorenal syndrome, and deceased were 0.863, 0.733, 0.71, and 0.69, respectively. The AUROCs of mixed microbial species for the diagnosis of cirrhosis and complication were 0.808 and 0.847, respectively. According to the metabolic profile, 5 increased fecal metabolites in patients with cirrhosis were biomarkers (AUROC >0.880) for the diagnosis of cirrhosis and complications. Clinical markers were significantly correlated with the gut microbiota and metabolites. Conclusions Cirrhosis-dependent gut microbiota and metabolites present unique signatures that can be used as noninvasive biomarkers for the diagnosis of cirrhosis and its complications.

Background/Aims: This study aimed to review the indications, methods, cooperation, complications, and outcomes of percutaneous endoscopic gastrostomy (PEG). Methods: Questionnaires were sent to 200 hospitals, of which 62 returned their questionnaires, with a response rate of approximately 30%. Descriptive statistics were calculated to analyze the responses to the questionnaires. Results: In 2019, a total of 1,052 PEGs were performed in 1,017 patients at 62 hospitals. The main group who underwent PEG was older adult patients with brain disease, particularly stroke.Nutritional supply was an important purpose of the PEG procedure. “The pull method” was the most commonly used for initial PEG insertion. The complications related to PEG were mostly mild, with leakage being the most common. Patients who underwent PEG procedures were primarily educated regarding the post-procedure management and complications related to PEG.Preoperative meetings were skipped at >50% of the institutions. Regarding the cooperation between the nutrition support team (NST) and the physician performing PEG, few endoscopists answered that they cooperated with NST before and after PEG. Moreover, the rate of NST certification obtained by physicians performing PEG and the frequency of attendance at NST-related conferences were relatively low. Conclusions This study shows a similar trend to that found in the previous PEG guidelines.However, it covers new aspects, including team-based work for PEG procedure, nutrition support, and education for patients and guardians. Therefore, each medical institution needs to select an appropriate method considering the medical environment and doctor’s abilities.

Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019.In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×105 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×102 PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×102 PFU-virusinfected lungs from 2 dpi, but not in 1×105 PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×105PFU; however, 1×102 PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.

Background: Even amid the coronavirus disease-19 (COVID-19) pandemic, the spread of multidrug-resistant bacteria and infection control are still important tasks. After recognizing the carbapenem-resistant Acinetobacter baumannii (CRAB) outbreak that occurred in the isolation room for COVID-19, we would like to introduce what infection control measures were implemented to eradicate it. Materials and Methods: All COVID-19 patients with CRAB in any specimen admitted to the COVID-19 isolation ward of the tertiary hospital in Korea from October to November 2021 were analyzed. Results: During the outbreak, 23 patients with COVID-19 and CRAB infections were identified. The index case was an 85-year-old female referred from a long-term care facility. CRAB was identified in sputum culture in most patients (91.3%). The CRAB outbreak occurred mainly in the rooms around the index case. Environmental cultures on the floor, air inlet, air outlet, and window frame of the rooms were performed. The antimicrobial resistance patterns of CRAB from patients and the environment were identical; whole-genome sequencing analyses revealed isolated clonality. Infection control measures with enhanced environmental cleaning using 1,000 ppm sodium hypochlorite and phenolic compounds, enhanced hand hygiene, additional education, and mandatory additional gowning and gloving of COVID-19 personal protective equipment (PPE) were applied on 29 October. No CRAB infection cases occurred from 2 November for two weeks. Conclusion In addition to applying PPE and COVID-19 precautions in COVID-19 isolation wards, adhering to strict contact precautions along with environmental control can help prevent the spread of multidrug-resistant bacteria.

Postoperative pathological diagnosis of differentiated thyroid cancer (DTC) is important to confirm the diagnosis and predict the risk of recurrence and death. Further treatment plans, such as completion thyroidectomy, radioiodine remnant ablation, or external beam radiation therapy, are then opted for to reduce the predicted risk of recurrence or death. The World Health Organization has classified thyroid cancers into seven distinct categories based on the molecular profile and tumor cell origin. Our recommendation is applicable to differentiated follicular cell-derived carcinoma, the most common form of thyroid cancer, and cribriform morular thyroid carcinoma. Postoperative clinical and pathological staging is recommended for all patients with DTC to determine their prognosis and subsequent treatment decisions. In particular, the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) staging system is recommended for staging DTCs for disease mortality prediction and national cancer registries. The information in the pathology report, including histologic features of the tumor that are necessary for AJCC/UICC staging and recurrence prediction, can help assess the patient’s risk.

Thyroid nodules represent a prevalent condition that is detectable via palpation or ultrasound. In recent years, there has been a paradigm shift toward enhanced diagnostic precision and less aggressive therapeutic approaches, highlighting the growing necessity for tailored clinical recommendations to optimize patient outcomes. The Korean Thyroid Association (KTA) has developed guidelines for managing patients with thyroid nodules, following a comprehensive review by task force members of the relevant literature identified via electronic database searches. The recommendations are provided with a level of recommendation for each section. The guidelines encompass thyroid cancer screening in high-risk groups, appropriate diagnostic methods for thyroid nodules, role of pathologic and molecular marker testing in making a diagnosis, long-term follow-up and treatment of benign thyroid nodules, and special considerations for pregnant women. The major revisions that were made in the 2023 guidelines were the definition of high-risk groups for thyroid cancer screening, application of the revised Korean Thyroid Imaging Reporting and Data System (K-TIRADS), addition of the role of core needle biopsy and molecular marker tests, application of active surveillance in patients with low-risk papillary thyroid microcarcinoma, and updated indications for nonsurgical treatment of benign thyroid nodules. In the 2024 revision of the KTA guidelines for thyroid cancer, the evidence for some recommendations has been updated to address the tumor size in the context of active surveillance in patients with low-risk thyroid cancer and the surgical size cutoff. These evidence-based recommendations serve to inform clinical decision-making in the management of thyroid nodules, thereby facilitating the delivery of optimal and efficacious treatments to patients.

Differentiated thyroid cancer demonstrates a wide range of clinical presentations, from very indolent cases to those with an aggressive prognosis. Therefore, diagnosing and treating each cancer appropriately based on its risk status is important. The Korean Thyroid Association (KTA) has provided and amended the clinical guidelines for thyroid cancer management since 2007. The main changes in this revised 2024 guideline include 1) individualization of surgical extent according to pathological tests and clinical findings, 2) application of active surveillance in low-risk papillary thyroid microcarcinoma, 3) indications for minimally invasive surgery, 4) adoption of World Health Organization pathological diagnostic criteria and definition of terminology in Korean, 5) update on literature evidence of recurrence risk for initial risk stratification, 6) addition of the role of molecular testing, 7) addition of definition of initial risk stratification and targeting thyroid stimulating hormone (TSH) concentrations according to ongoing risk stratification (ORS), 8) addition of treatment of perioperative hypoparathyroidism, 9) update on systemic chemotherapy, and 10) addition of treatment for pediatric patients with thyroid cancer.