• Journal of the Korean Society of Safety
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• v.9 no.4
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• pp.17-28
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• 1994

Chip breaking is important in lathe work for maintaining good surface of the products and safety of operator. The purpose of this study is to investigate the performance of chip breaking and chip shape resulted from the carbide inserts with grooved type and obstruction type chip breaker. Experiments have been performed under the following cutting conditions, (1) constant cutting speed with variable depth of cut and feed rate, (2) constant depth of cut with variable cutting speed and feed rate. Also, the flying distance of chip and it's distribution have been investigated. As a results, good performance of chip breaking can be obtained for small radius of curvature and land width of grooved type chip breaker. And the thickness of chip increase with the increase of feed rate and decrease of cutting speed, and the chip breaking becomes easier with the increase of chip thickness due to the large deformation rate. Obstraction type chip breaker shows better performance of surface roughness than the grooved type. The flying distance of the chips over 90% are less than 1 meter, and the distance decreases as the feed rate decreases.

• The Journal of the Korean dental association
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• v.48 no.3
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• pp.178-183
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• 2010

Obstructive Sleep Apnea(OSA) is a form of sleep disordered breathing(SDB) characterized by the occurrence of episodes of complete or partial upper airway obstruction during sleep that is often quantified as the apnea-hyponea index(AHI). It is increasingly being recognized that OSA is a public health hazard and there is increasing evidence that it is associated with an increase in morbidity. Early recognition and diagnosis of this condition may lead to earlier treatments (eg, CPAP, Oral appliances) with reduction of the risk of metabolic disease, cardiovascular diseases, such as hypertension, ischemic heart disease, arrhythmias and pulmonary hypertension.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.17 no.3
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• pp.296-301
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• 1995

Acute mediastinitis is almost always secondary to some other condition, and most cases are due to esophageal perforation. Although acute mediastinitis from odontogenic infection is extremely rare in the era of antibiotic drugs, some more fulminant odontogenic infections can produce complications including airway obstruction, necrotizing fascitis and extension of the infection to thorax. Irrespective of the changing incidence of etiologic factors, unless the pathophysiology of acute mediastinitis and its causes are understood and the conditions promptly recognized and properly treated, the result may be prolonged illness and even death. We experienced a case of odontogenic infection followed by acute mediastinitis and present review of literature.

• Journal of The Korean Dental Society of Anesthesiology
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• v.13 no.4
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• pp.189-193
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• 2013

We experienced dfficult airway management in a patient who had Ludwig angina with morbid obesity, dfficulty with mouth opening and neck extension. We planned to perform awake-nasotracheal intubation with fiberoptic bronchoscopy but the patient's condition was not suitable to do this procedure. Thus, we tried fiberoptic nasotracheal intubation under general anesthesia but we experienced difficult airway management due to epistaxis. We tried to use video laryngoscope instead of fiberpotic bronchoscopy but also failed to guide the tube into trachea due to limited mouth opening. We used video laryngoscope to make a view of vocal cord and used fiberoptic bronchoscope as an intubation guide of endotrachedal tube and successfully intubated the patient.

• Korean Journal of Bronchoesophagology
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• v.3 no.1
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• pp.128-136
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• 1997

Laryngomalacia is the most common cause of stridor in infant. It is a relatively benign self-limiting condition, but in severe cases, it results in obstructive sleep apnea, cor pulmonale , gastroesophageal reflux, failre to thrive, pectus excavatum, respiratory failure and death. When the airway obstruction related to laryngomalacia becomes significant, surgical correction of the underlying laryngeal deformity is indicated. Numerous reports provide evidence to support the trimming supraglottic soft tissue by using either conventional instruments or the surgical laser for treatment of severe laryngomalacia. Recently, authors experienced a case of laryngomalacia with Trisomy 13 (Patau syndrome) which had three times respiratory arrest and was treated with laser aryepiglottoplasty. We report this case with review of the literatures.

• Journal of Chest Surgery
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• v.54 no.5
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• pp.389-392
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• 2021

Double outlet right ventricle (DORV) with pulmonary atresia (PA) is an uncommon congenital disease. Because of anatomical and physiological anomalies in the systemic and pulmonary circulation, corrective surgery may be challenging. We present the case of a patient with DORV and PA. This condition was successfully corrected using a modified Nikaidoh procedure, resulting in reduced obstruction of the left ventricular outflow tract.

• Tuberculosis and Respiratory Diseases
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• v.43 no.3
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• pp.377-387
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• 1996

Background : In 1980, WHO made a definition in which the term "impairment" as applied to the respiratory system is used to describe loss of lung function, "disability" the resulting diminution in exercise capacity. The measurement of pulmonary function during exercise would give us information about overall functional capacity and respiratory performance that would be lacking in tests performed at rest. We conducted this study to investigate the role of resting pulmonary function test and exercise test for assessing impairment/disability in patients with chronic airflow obstruction(CAO). Method : We studied 19 patients with CAO. The spirometry and body plethysmograph were performed in stable condition. And then patients performed a progressive incremental exercise test to a symptom-limited maximum using cycle ergometer. Patients were divided in two groups, severe and non-severe impairment, according to the resting PFTs and compaired each other. A patient was considered to be severely impaired if FVC < 50 %, FEV1 < 40 % or FEV1/FVC < 40 %. Results : 1) The airway obstruction and hypoxemia of severe impairment group were more severe and exercise performance was markedly reduced compairing to non-severe impairment group. 2) The severe impairment group showed ventilatory limitation during exercise test and the limiting symptomes ware dyspnea in 9/10 patients. 3) The impairment and disability of the patients with tuberculous destructed lung were most marked in patients with CAO. 4) The FEV1 was the most prevalent criterion for the determination of severe impairment based on resting PFTs and was the valuable best correlated to V02max(r=0.81, p < 0.001). 5) The sensitivity of exercise limits for predicting severe disability according to resting PFTs was 80 % and specificity 89 %. Conclusion : In patients with severe CAO, FEV1 is a good predictive of exercise performance and impairment measured by resting PFTs can predict a disability by exercise test.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.6
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• pp.427-431
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• 2013

Angioedema is defined as self-limited, localized swelling. The swelling is asymmetric, non-pitting, and non-tender. Common locations of swelling include periorbital area, lips, tongue, extremities, and bowel wall. A 54-year-old woman visited our hospital with the clinical complaint of left maxillary swelling. Swelling of the left maxillary area was diffuse and temperature of the involved area was normal. No infectious source was found on panoramic radiography and cone-beam computed tomography. After considering the patient's medical history and assessing clinical examination, we suspected angioedema and administered corticosteroid only. In the oral and maxillofacial area, proper diagnosis and prompt treatment of angioedema is important because angioedema of the tongue or larynx may lead to airway obstruction or a life-threatening condition.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.10 no.1
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• pp.31-37
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• 2014

The general local cause of gingival bleeding is the vessel engorgement and erosion by odontogenic infection. Abnormal gingival bleeding is also associated with systemic causes. Bleeding disorders in which continuous gingival bleeding is encountered include the followings : vascular abnormalities, platelet disorders, hypoprothrombinemia and other coagulation defects. There are classic methods for gingival bleeding control, such as, direct pressure, electrocoagulation, suture, crushing and application of hemostatic agents. If the continuous gingival bleeding is not stopped in spite of the conventional methods, the life of patient is threatened owing to upper airway obstruction, syncope, vomiting and hypovolemic shock. Therefore, the rapid and correct hemostatic method is very important in the emergency condition. This is a case report of continuous gingival bleeding control by primary endodontic drainage & suture in a disabled patient with systemic bleeding disorders.

• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.4
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• pp.327-330
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• 2015

The safety and success of dental sedation for children depend mainly on respiratory status of patients. A special condition, that is, nasal breathing in supine position with their oral airway blocked by rubber dam, should be considered. Therefore, irrespective of medical consultation, pediatric dentists themselves should do respiratory assessment especially adenotonsillar hypertrophy, nasal obstruction, posterior nasal drainage and airway hypersensitivity. Patients with sinusitis, allergic rhinitis, asthma, snoring and OSAS(obstructive sleep apnea syndrome) can induce the sedation failure and complete management of these can improve the safety of dental sedation.