PURPOSE: The purpose of this in vitro study was to investigate the fracture loads and modes of failure for the full range of natural teeth under simulated occlusal loading. MATERIALS AND METHODS: One hundred and forty natural teeth were taken from mandibles and maxillas of patients. There were 14 groups of teeth with 10 teeth in each group (5 males and 5 females). Each specimen was embedded in resin and mounted on a positioning jig, with the long axis of the tooth at an inclined angle of 30 degrees. A universal testing machine was used to measure the compression load at which fracture of the tooth specimen occurred; loads were applied on the incisal edge and/or functional cusp. RESULTS: The mean fracture load for the mandibular first premolar was the highest (2002 N) of all the types of teeth, while the mean fracture load for the maxillary first premolar was the lowest (525 N). Mean fracture loads for the mandibular and maxillary incisors, and the first and second maxillary premolars, had significantly lower values compared to the other types of teeth. The mean fracture load for the teeth from males was significantly greater than that for the teeth from females. There was an inverse relationship between age and mean fracture load, in which older teeth had lower fracture loads compared to younger teeth. CONCLUSION: The mean fracture loads for natural teeth were significantly different, with dependence on tooth position and the sex and age of the individual.
Bicuspid ; Female ; Humans ; In Vitro Techniques ; Incisor ; Male ; Mandible ; Maxilla ; Tooth

The prevalence of colon cancer is increasing in Korea and the principal strategy of its management is early detection and surgical resection. For the early detection of colon cancer, endoscopic evaluation is important and the ability to find out early stage small lesion is needed for the endoscopist. To find out encloscopic features of early colon cancer, we reviewed 17 cases of early colon cancer who have admitted to Seoul National University Hospital from January 1982 to December 1993. 1)59% of the lesions were located in rectum and the size ranged from 0.7cm to 9cm, all of the 17 cases showed polypoid mass contour and the surface of them had erosion, hyperemia, ulceration and easy touch bleeding tendency. 2) Colon cancer was diagnosed by endoscopic gross findings in 41% and endoscopic biopsy could confirm colon cancer in 70%. However, barium enema could diagnose only 41% of early colon cancer. 3) Five cases were operated under the diagnosis of colonic adenoma which were large(>3 cm) villous type or contained severe dysplasia 4) Submucosal tumor infiltration was found in 10 cases and 65% had associated adenoma 5) Lymph node involvement was none and there was no recurrence in 47 month follow up period after various surgical treatments.
Adenoma ; Barium ; Biopsy ; Colon* ; Colonic Neoplasms* ; Diagnosis ; Endoscopy ; Enema ; Follow-Up Studies ; Hemorrhage ; Hyperemia ; Korea ; Lymph Nodes ; Prevalence ; Rectum ; Recurrence ; Seoul ; Ulcer

The endoscopic diagnosis of gastric carcinoid has been considered difficult. Reported cases of this tumor diagnosed by endoscopic examination are rare. And the gastric carcinoid with massive upper gastrointestinal bleeding is a rare disease entity. We experienced a case of gastric carcinoid admitted to the hospital because of hematemesis, melena and syncope. And it was diagnosed by endoscopic biopsy, although it resembled type IIa+IIc early gastric cancer at endoscopic examination. To our knowledge, this is the first case report of gastric carcinoid tumor mimicking early gastric cancer. So we report this case with a review of relevant literatures.
Biopsy ; Carcinoid Tumor* ; Diagnosis ; Hematemesis ; Hemorrhage ; Melena ; Rare Diseases ; Stomach Neoplasms* ; Syncope

Early gastric cancer(EGC) has been proved to be a malignant tumor with favorable prognosis in contrast to the advanced one, thus early diagnosis has always been the emphasis regardless its type. In particular, diagnosis of superficial flat type EGC(IIb) is extremely difficult on gross inspection. The aim of this study is to review the clinical features of the patients with EGC type IIb, with special reference to the endoscopic appearance of tumor. We reviewed the medical records and endoscopic findings of 13 patients which were thereafter surgically resected and pathologically proven EGC type IIb at SNUH from 1989 to 1993. The depressed lesion was observed most frequently in EGC type IIb. The endoscopic suggestion of EGC type IIb were given initially with mucosal bleeding and discoloration. In 3 cases (20%), tumor extended to the submucosa and in only 1 case, lymph node metastasis was found. Four patients(30.9%) had another coincidental EGC or peptic ulcer. Every possible effort is needed not to omit the resectable cancer when the mucosal bleeding and discoloration is observed. Careful observation is recommended not to overlook coincidental lesions.
Diagnosis ; Early Diagnosis ; Hemorrhage ; Humans ; Lymph Nodes ; Medical Records ; Neoplasm Metastasis ; Peptic Ulcer ; Prognosis ; Stomach Neoplasms*

Objective: Endovascular coil embolization is the primary treatment modality for intracranial aneurysms. However, its long-term durability remains of concern, with a considerable proportion of cases requiring aneurysm reopening and retreatment. Therefore, establishing optimal follow-up imaging protocols is necessary to ensure a durable occlusion. This study aimed to develop guidelines for follow-up imaging strategies after endovascular treatment of intracranial aneurysms. Methods: A committee comprising members of the Korean Neuroendovascular Society and other relevant societies was formed. A literature review and analyses of the major published guidelines were conducted to gather evidence. A panel of 40 experts convened to achieve a consensus on the recommendations using the modified Delphi method. Results: The panel members reached the following consensus: 1. Schedule the initial follow-up imaging within 3-6 months of treatment. 2. Noninvasive imaging modalities, such as three-dimensional time-of-flight magnetic resonance angiography (MRA) or contrast-enhanced MRA, are alternatives to digital subtraction angiography (DSA) during the first follow-up. 3. Schedule mid-term follow-up imaging at 1, 2, 4, and 6 years after the initial treatment. 4. If noninvasive imaging reveals unstable changes in the treated aneurysms, DSA should be considered. 5. Consider late-term follow-up imaging every 3–5 years for lifelong monitoring of patients with unstable changes or at high risk of recurrence. Conclusions The guidelines aim to provide physicians with the information to make informed decisions and provide patients with high-quality care. However, owing to a lack of specific recommendations and scientific data, these guidelines are based on expert consensus and should be considered in conjunction with individual patient characteristics and circumstances.

The aim of the study was to evaluate the prevalence of restrictive ventilatory defect and to determine the risk factors in subjects with spirometrically-defined restrictive ventilatory defect. We used the population-based, fourth-2, 3 (2008, 2009) and fifth (2010-2012) Korea National Health and Nutrition Examination Survey (KNHANES) to analyze 15,073 subjects, aged > or =40 yr who underwent spirometry. Chest radiographs were also analyzed to identify restrictive lung disease. Spirometrically-defined restrictive ventilatory defect (FEV1/FVC> or =70% and FVC<80% of mean predicted value) was detected in 11.3% (n= 1,709) of subjects aged > or =40 yr. The prevalence increased to 12.3% on using the lower limit of normal (LLN) criteria. Approximately 99.4% of subjects were classified as mild restrictive. Among these, 11.3% had inactive tuberculosis (TB) lesion, 2.2% cardiac disease, 2.0% previous operation scar or radiation injury and/or mediastinal disease, and 7.4% other pulmonary disease suggestive of restrictive lung diseases on chest radiograph. Evidence of previous TB history was independently associated with restrictive ventilatory defect (odds ratios [OR], 1.78; 95% confidence interval, 1.45-2.18) after adjustment for gender, age, smoking, area for residence and body mass index. The prevalence of restrictive ventilatory defect among the nationwide population in Korea was 11.3% with fixed ratio criterion and 12.3% with LLN criterion. Most cases were of the mild restrictive category and previous TB history is the independent risk factor for restrictive ventilatory defect.
Adult ; Age Distribution ; Aged ; Aged, 80 and over ; Educational Status ; Female ; Health Care Surveys ; Housing ; Humans ; Income ; Lung Diseases, Obstructive/*diagnosis/*epidemiology ; Male ; Middle Aged ; Prevalence ; Reproducibility of Results ; Republic of Korea/epidemiology ; Risk Factors ; Sensitivity and Specificity ; Sex Distribution ; Smoking/*epidemiology ; Spirometry/*statistics & numerical data