• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.2
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• pp.213-230
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• 2008

The aim of this study was to analyze the initial movement and the stress distribution of each tooth and periodontal ligament during the lingual lever-arm retraction of 6 maxillary incisors using FEA. Two kinds of finite element models were produced: 2-properties model (simple model) and 24-properties model (multi model) according to the material property assignment. The subject was an adult male of 23 years old. The DICOM images through the CT of the patient were converted into the 3D image model of a skull using the Mimics (version 10.11, Materialise's interactive Medical Image Control System, Materialise, Belgium). After series of calculating, remeshing, exporting, importing process and volume mesh process was performed, FEA models were produced. FEA models are consisted of maxilla, maxillary central incisor, lateral incisor, canine, periodontal ligaments and lingual traction arm. The boundary conditions fixed the movements of posterior, sagittal and upper part of the model to the directions of X, Y, Z axis respectively. The model was set to be symmetrical to X axis. Through the center of resistance of maxilla complex, a retraction force of 200g was applied horizontally to the occlusal plane. Under this conditions, the initial movements and stress distributions were evaluated by 3D FEA. In the result, the amount of posterior movement was larger in the multi model than in the simple model as well as the amount of vertically rotation. The pattern of the posterior movement in the central incisors and lateral incisors was controlled tipping movement, and the amount was larger than in the canine. But the amount of root movement of the canine was larger than others. The incisor rotated downwardly and the canines upwardly around contact points of lateral incisor and canine in the both models. The values of stress are similar in the both simple and multi model.

• Sleep Medicine and Psychophysiology
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• v.16 no.2
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• pp.65-73
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• 2009

Objectives: The purpose of this study was to assess the clinical and polysomnographic characteristics of Korean patients with obstructive sleep apnea syndrome (OSAS), especially in relation to differences due to age and gender. Methods: All subjects were consecutive patients who were proven to have OSAS with nocturnal polysomnography. They were interviewed with a structured interview format including sociodemographic information, past medical history, medication, and sleep-related history. Simultaneously, they were also given Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS) to answer in order to check subjective sleep quality and subjective sleepiness. Results: Mean age of the 308 subjects was $49.5{\pm}$13.3 years, with 77.6% of the subjects being males and 22.4% of the subjects being females. The aging effects on the sleep architecture in Korean OSAS corresponded with normal aging, but with the effect of OSAS itself superimposed, the extent of aging effects was more marked than that of normal aging. The severity of Korean patients of OSAS was not correlated with age. When divided into age subgroups, significant correlation was found between RDI and BMI in patients of each subgroup of those in the 4th to 7th decades. The oldest subgroup (>70 years) described their subjective sleep quality as poorer than any other age subgroups, despite of less subjective drowsiness. The severity of OSAS and the change of sleep architecture of male subjects turned out to be severer than those of female ones. The female/male ratio of the subjects tended to increase with aging. Conclusions: The aging effect on the sleep architecture in Korean OSAS seems to be a mixture of the changes by normal aging and sleep disorder per se. The severity of OSAS was not correlated with age, but highly correlated with BMI. The severity of OSAS and the change of sleep architecture of male patients were severer than those of female ones.

• Sleep Medicine and Psychophysiology
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• v.14 no.2
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• pp.92-98
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• 2007

Objectives: Obstructive sleep apnea syndrome (OSAS) is the most common form of sleep-disordered breathing and often presents with comorbid depressive symptoms. In this study, we evaluated the relationship between depressive symptoms and sleep parameters as measured by nocturnal polysomnography (NPSG) and simultaneous wrist actigraphy. Methods: Two hundred sixty-four subjects with clinically suspected cases of OSAS underwent one-night polysomnography, while simultaneously wearing a wrist actigraphy device. They also completed two questionnaires；the Epworth Sleepiness Scale-Korean version (ESS-K) and the Beck Depression Inventory (BDI). Of the cases studied, 105 subjects were proven by NSPG to have OSAS without other sleep disorders. NPSG and wrist actigraphy data from the subjects were analyzed. Pearson correlation and paired t-test were used in order to evaluate the relationship between depressive symptoms and sleep-parameters. Results: Mean age of the subjects was $46.1{\pm}13.1$ years. Means of the ESS-K score and BDI scores were $10.9{\pm}4.7$ and $12.8{\pm}8.1$, respectively. NPSG sleep parameters significantly differed from those of wrist actigraphy. There was no correlation found between subjects' respiratory disturbance index (RDI) and BDI scores. When directly comparing sleep parameters between subjects who were more depressed versus subjects who were less depressed, both total sleep time and sleep efficiency were decreased in the more depressed. A correlation between RDI and ESS-K scores was also found in the more depressed group. Conclusions: Although our findings suggest that there is no relationship between RDI and depressive symptoms, there are other significant differences in the sleep parameters between subjects who are more depressed versus those without depression. We recommend that patients with depression should also be evaluated for clinical symptoms of OSAS.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.1
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• pp.53-61
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• 2020

Midazolam is a short-acting benzodiazepine that is widely used in pediatric dental sedation. However, its clinical effectiveness as an intravenous sedative agent in children has not been widely documented. A retrospective study was conducted to evaluate the efficacy and safety of intravenous midazolam and nitrous oxide inhalation sedation in pediatric dental treatment. The subjects were 115 patients (118 cases) who received dental treatment under intravenous midazolam and nitrous oxide inhalation sedation. Demographic factors, general health status, sedation time, midazolam and nitrous oxide dosage, and success rate of sedation were evaluated from electronic medical records. Behavioral management was the main reason of choosing sedation. Mean duration of sedation was 56.7 minutes for surgical treatment, and 74.4 minutes for restorative treatment. The initial dosage of intravenous midazolam was 0.051 ± 0.019 mg/kg. In 34 cases (28.8%), additional midazolam of 0.036 ± 0.057 mg/kg was delivered during the treatment. The concentration of nitrous oxide was maintained between 40% and 50%. The success rate of sedation was 99% (n = 117). In 1 case, laryngospasm occurred and the patient was reversed with benzodiazepine antagonist, flumazenil. Intravenous midazolam sedation with nitrous oxide was shown to be clinically effective for the dental treatment in children, if administered by trained personnel and patients are carefully selected in accordance with guidelines.

• Tuberculosis and Respiratory Diseases
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• v.49 no.1
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• pp.30-36
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• 2000

Background : The purpose of decortication is to eliminate the infection focus and to improve the decreased lung function due to chronic empyema. However, lung function is not improved in all cases. It would be clinically useful if we could predict prepoperatively whether lung function would improve after decortication. The purpose of this study is to find useful indices for predicting the possible improvement of lung function after decortication. Method : The medical records of 37 tuberculous empyema patients who underwent pleural decortication were analyzed retrospectively from 1990 to 1996. The measurements of preoperative and postoperative foræd vital capacity(FVC) were used for evaluating the effects of decortication. Results : The sex ratio was 29:8 (male to female), and the median age was 34 years. The time interval between the formation of empyema and operation was 1 month to 30 years. Postoperative pulmonary function test was performed 5.4$\pm$2.6 months later. FVC(forced vital capacity) was significantly increased from 2.77$\pm$0.67(L) to 2.95$\pm$0.81(L). Interestingly, postoperative pulmonary function was significantly improved in patients who were less than 40 years old, within 4 months after diagnosis of tuberculous empyema, in the group with FVC of less than 60% of the predicted value and in the absence of calcification. Conclusion : The improvement of lung function after decortication was expected in patients younger than 40 years old, within 4 months after diagnosis of tuberculous empyema, in the group having less than 60% of the predicted FVC, without calcification.

• Tuberculosis and Respiratory Diseases
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• v.41 no.5
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• pp.537-545
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• 1994

Background: In 1987, the British Thoracic Society (BTS) subjected an extensive list of patient variables to statistical analysis in a prospective study of prognosis in 453 adults with community-acquired pneumonia and, subsequently published guidelines for management of severe community acquired pneumonia. It was hoped that those at risk of dying from community acquired pneumonia could be easily identified and treated appropriately, thereby reducing mortality. To date, severe community acquired pneumonia has not been well studied in Korea. Therefore, we studied retrospectively 10 patients dying of severe community acquired pneumonia in Dongsan Hospital to see clinical manifestations of dying of severe community-acquired pneumonia. Methods: Between July 1987 and july 1993, 498 patients were admitted to Keimyung University Dongsan Hospital with community acquired pneumonia, and 77 of them received intensive care. Of the 77 patients, 10 patients died. We reviewed medical records of these patients. Results: 1) The mean age of the patients was 56.2 years(range, 25 to 75 years). There were 7 men and 3 women. Seven patients(70%) were older than 60years of age. 2) The clinical features on admission were as follows: tachypnca, hypoxemia, mental change, cyanosis, leukopenia, leukocytosis, azotemia, hypotension, hypoalbuminemia in order of frequency. Three patients had one abnormal physical finding, 3 patients had 2, 2 patients had 3, and 2 patients had none of these abnormal physical findings. All patients had at least one of the abnormal laboratory findings. 3) A potential bacterial pathogen was isolated in sputum culture from 2 patients. One was E.coli, the other Enterobacter species. Sputum stain were positive in eight cases (G(+)cocci in six, G(+) cocci and G(-)bacilli in two). 4) Features of respiratory failure were the main reasons for ICU transfer, but two patients were transferred only following a cardiac or respiratory arrest in the general ward. 5) The mean of 2.7 different antibiotics were given to the patients. The aminoglycoside and first generation cephalosporin were the most frequently prescribed antibiotics, followed by the third generation cephalosporin and vancomycin. The most frequently prescribed antibiotics combination was a 1st generation cephalosporin plus an aminoglycoside. 6) Seven patients death(70%) occured after admission within the first five days, and a mean duration of hospitaliztion was 11.2 days. Conclusion: As the results show most death occured within the first five days after admission and aged patients; consequently, an aggressive intensive treatment should be provided early to the patients with severe community acquired pneumonia, and we should pay more attention to the aged patients.

• Tuberculosis and Respiratory Diseases
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• v.51 no.4
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• pp.334-345
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• 2001

Background : Pulmonary tuberculosis(TB) is still prevalent and remains a significant clinical problem for the elderly. However, the disease presents in many ways, and there are frequent adverse drug reactions that may prevent the early diagnosis and treatment of elderly TB patients compared to the young. The purpose of this study was to determine whether or not there are any differences in the clinical feature of pulmonary tuberculosis(TB) in both the diagnosis and treatment between the young (less than 64 years) and the elderly (65 years and more). Methods : The medical records of 125 young and 70 elderly pulmonary TB patients, who were diagnosed with and treated for pulmonary TB at the Seoul Municipal Boramae Hospital from November 1991 to January 1997, were analyzed retrospectively. Results : Anorexia(12% vs. 31.4%), general weakness (20.0% vs. 54.3%), dyspnea(21.6% vs. 37.1%) and an abnormal mentality (0.8% vs. 15.7%) were more frequent presenting symptoms in elderly TB patients, whereas hemoptysis (32.8% vs. 10.0%) and fever (BT > $37^{\circ}C$, 58.4% vs. 35.7%) were more frequent in the young. The elderly had a higher number of cardiovascular and chronic obstructive pulmonary diseases as underlying illnesses. In chest PA, there were no differences in the location of the TB lesion, but the appearances were initially diagnosed more frequently as pneumonia or lung cancer (8.8% vs. 30.0%, p<0.05) in the elderly. There was no difference in the detection rate of acid fast bacilli(AFB) in the sputum between the two groups. There were no differences in the treatment response and follow-up loss. However, adverse drug reactions (13.6% vs. 45.7%, p<0.05), and changes in medication (4.9% vs. 25.7%, p<0.05) during treatment occurred more frequently in the elderly. One among the 125 young patients died from tuberculosis whereas 6 among the 70 elderly patients died from the disease. Conclusion : Because the clinical and radiological presentations were more atypical, a sputum AFB smear and culture should be done immediately in the elderly who are TB. The elderly experienced more frequent adverse drug reactions and mortality during treatment, but the response to treatment was good and rapid.

• Tuberculosis and Respiratory Diseases
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• v.55 no.1
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• pp.31-40
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• 2003

Background : A CT scan is a useful modality for the diagnosis and evaluation of disease activity in patients with pulmonary tuberculosis. However, the CT diagnosis of pulmonary tuberculosis is sometimes difficult in patients with an atypical CT pattern, especially with lobar consolidation mimicking pneumonia. The aim of this study was to evaluate the clinical and CT features of pulmonary tuberculosis, simulating pneumonia, from a CT scan. Materials and Methods : The clinical and CT features in 21 patients, where the CT diagnosis was pneumonia, or the CT differential diagnosis included pneumonia, were retrospectively analyzed. Results : Of the 21 patients, 6 were immunocompromised, 15 presented with fever or leukocytosis and 15 showed positive sputum smear test for acid fast bacilli. Also, 17 of the 21 patients showed a positive sputum culture test. On the CT scan, consolidation was noted in all patients (100%), volume loss of the involved lobe or segment in 12 (57%), bronchogenic spread in 15 (71%), a cavity in 7 (33%) and bronchial wall thickening also in 7 (33%). The location of the consolidation revealed a relatively even distribution, with no specific predilection site. The other associated pulmonary diseases included ARDS, bronchiectasis, severe pulmonary emphysema, idiopathic pulmonary fibrosis and pulmonary alveolar proteinosis. Conclusion : In the immunocompromised patients, or patients with an underlying pulmonary disease, whose CT scans showed pulmonary consolidation, especially in association with findings of bronchogenic spread, a cavity or bronchial wall thickening, meticulous examination for pulmonary tuberculosis is recommended.

• Tuberculosis and Respiratory Diseases
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• v.60 no.3
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• pp.337-341
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• 2006

Objectives : Endobronchial anthracofibrotic pigmentation, which presents as dark black or brown pigmentation mucosal changes of multiple bronchi combined with bronchial fibrosis and obstruction, is not a rare finding when performing diagnostic bronchoscopy for Koreans. This study was performed to define the clinical characteristics and to determine the association of these finding with the Korean life style and such other diseases as coal workers, pneumoconiosis or tuberculosis in the patients with anthracofibrotic pigmentation. Methods : This retrospective analysis was conducted on 70 (5.2%) patients with endobronchial anthracofibrotic pigmentation, among a total of 1340 patients who underwent bronchoscopy. The distinctive clinical features, the personal life style, the past medical history, the histology and microbiology, the radiologic finding and the natures of the bronchoscopic lesions were analyzed. Results : This mean age of the patients with anthracofibrotic pigmentation was $60.6{\pm}9.2$ year old and the male to female ratio was 1:1.7. The common respiratory symptoms of these patients were coughing and sputum (81%, 57/70), and this was followed in order by dyspnea and hemoptysisir. The symptoms were not related with smoking and an occupational history such as being a coal worker and so on. Pneumonia was most common finding on the radiologic studies. On bronchoscopy, the right middle lobe bronchus was most commonly involved. The most common associated disease was tuberculosis, and 40 cases (57.1%) were diagnosed by AFB staining, TB PCR, bronchoscopic guided tissue biopsy and a past history of tuberculosis. Other diseases related with anthracotic pigmentation were hypertension, diabetes, COPD, lung cancer, pneumoconiosis and asthma. Conclusion : These results suggest that endobronchial anthracofibrotic pigmentation was mostly related with pulmonary tuberculosis rather than with coal- related disease. Endobronchial anthracofibrotic pigmentation was more prevalent in older age females in Korea.

• Tuberculosis and Respiratory Diseases
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• v.66 no.6
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• pp.437-443
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• 2009

Background: The aim of this study was to consider the significance of pleural fluid adenosine deaminase (ADA) activity combined with lymphocyte/neutrophil (L/N) ratio in the diagnosis of tuberculous pleurisy (TBpl) in a region of intermediate prevalence of tuberculosis (TB). Methods: We collected data from 388 patients with exudative pleural effusions. The final diagnoses were compared to the results from our diagnostic method using pleural fluid ADA and L/N ratio. Results: 108 patients had a final diagnosis of TBpl; 102 cases had high levels of ADA ($\geq$40 IU/L). When we considered ADA $\geq$40 IU/L as a diagnostic criterion, the sensitivity was 94.4%, specificity 87.5%, and posttest posttest probability 74.5%. However, when we considered ADA $\geq$40 IU/L combined with the L/N ratio $\geq$0.75 as a diagnostic criterion, the specificity and post-test probability were rose to 97.5% and 93%, respectively. The other causes of high ADA and L/N ratios were lymphoma and metastatic carcinoma, but mass-like lesions were found on the chest radiographs or CT scans. Conclusion: To evaluate the causes of exudative pleural effusions in a region of intermediate prevalence of tuberculosis, we recommend measuring the pleural fluid ADA and L/N ratio first. If the result is high and malignancies are not suspected, it may be diagnostic of TBpl.