• Journal of Yeungnam Medical Science
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• v.9 no.1
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• pp.189-196
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• 1992

Pre-surgical and post-surgical change in adult cleft lip and palate patient following Le Fort I advancement osteotomy combined with bone graft was evaluated clinically and cephalometically. We obtained a successful function and esthetic improvement. The bone graft of alveolo-palatal clefts provides a stable bone support to the adjacent teeth of the cleft area, and well union of adjacent bone tissue, the closure of oronasal fistula and improvement of speech problem. Le Fort I osteotomy following the ostectomy of nasal septum for advancement of the maxilla was obtained relative improvement of esthetics and functional occlusion. 1. The orthodontic correction was required before and after surgery. 2. In this case, there was a limited range of anterior advancement of the Premaxillary-segment due to the scar tissue. 3. After 8 months of operation, we could show the new bone deposition on the cleft site in dental radiograph and then the prosthetic treatement to the missing teeth was done.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.3
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• pp.205-215
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• 2008

SITES(Site Information and Total Environmental Data Management System) has been developed for the purpose of systematically managing site characteristics and environmental data produced during the pre-operational, operational, and post-closure phases of a radioactive waste disposal facility. SITES is an integration system, which consists of 4 modules, to be available for maintenance of site characteristics data, for safety assessment, and for site/environment monitoring; site environmental data management module(SECURE), integrated safety assessment module(SAINT), site/environment monitoring module(SUDAL) and geological information module for geological data management(SITES-GIS). Each module has its database with the functions of browsing, storing, and reporting data and information. Data from SECURE and SUDAL are interconnected to be utilized as inputs to SAINT. SAINT has the functions that multi-user can access simultaneously via client-server system, and the safety assessment results can be managed with its embedded Quality Assurance feature. Comparison between assessment results and environmental monitoring data can be made and visualized in SUDAL and SITES-GIS. Also, SUDAL is designed that the periodic monitoring data and information could be opened to the public via internet homepage. SITES has applied to the Wolsong low- and intermediate-level radioactive waste disposal center in Korea, and is expected to enhance the function of site/environment monitoring in other nuclear-related facilities and also in industrial facilities handling hazardous materials.

• Korean Journal of Bronchoesophagology
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• v.5 no.2
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• pp.130-137
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• 1999

Background and Objectives : Provox, a recently developed tracheoesophageal prosthesis, had been widely used for voice rehabilitation after total laryngectomy for its low resistance and easiness of speech ability. But, long-term use of Provox resulted in many complications and resulted in cessation of Provox as a primary method of vocal rehabilitation. The aim of this study is to report Provox-related problems and the long-term results of Provox voice prosthesis. Materials and Methods : Medical records from patients who had undergone total laryngectomy with Provox insertion at seoul National University Hospital between January 1993 and December 1998 were reviewed retrospectively. Results : 36 patients had used 79 Provox voice prostheses during the observed period. The most common complication causing prosthesis change or removal was leakage and/or aspiration, followed by granulation formation, crusting and/or obstruction, and non-function. Median in situ lifetime of Provox was 274 days and 1-year-in situ rate was 31.0% Among 36 patients, 17 patients had undergone tracheoesophageal shunt closure at the last follow-up visit. 10 patients had complications but got along without further treatments, and 1 patient changed to Blom-Singer voice prosthesis. Only 8 patients experienced no complication, and 5 out of whom had several times of Provox change. Conclusion : long-term use of Provox resulted in discontinuation of its use due to complications in many cases. A better voice prosthesis with lower complication rate and longer in situ lifetime is needed.

• Journal of Chest Surgery
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• v.29 no.10
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• pp.1118-1122
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• 1996

From January 1990 through December 1995, 43 patients underwent diaphragmatic plication for the management of phrenic nerve palsy .complicating various pediatric cardiovascular surgery. Their mean age at plication was 11.1 months and sex ratio was 31 males to 12 females. In order of decreasing incidence, the primary cardiovascular procedures included modified Blalock-Taussig shunt (7), total correction for the Tetralogy of Falloff (7), arterial switch operation (6), unifocalization for the pulmonary atresia with VSD (3), modified Fontan operation (3), VSD patch closure (3) and others. The involved sides of diaphragm were right in 17, left in 2) and bilateral in 3. Extensive pericardial resection with electocauterization of resected margin was thought to be the most common cause of phrenic nerve palsy (20). The interval between primary operation and plication ranged from the day of operation to 98 days (median 11 days). The methods of plication were central pleating technique(plication with phrenic nerve branch preservation) in 41, and other technique In 2. 10 patients died after plication (7: early, 3; late), and the causes of death were thought to be unrelated to plication itself. Among the 36 early survivors, extubation or cessation of positive pressure ventilation could be accomplished between 1 and 24 days postoperatively(mean : 4.5). Cumulative follow-up was 92 patient years without major complications. Postoperative follow-up fluoroscopy was performed in 6 patients, and the location and movement of plicated diaphragms were satisfactory in 5 patients. We concluded that diaphragmatic plication with preservation of phrenic n rve branch could lead to cessation of positive pressure ventilation and complete recovery of diaphragmatic function in the long term, unless the phrenic nerve was irreversibly damaged.

• Journal of Environmental Science International
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• v.19 no.11
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• pp.1423-1436
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• 2010

The effects of meteorological and reclaiming conditions on the reduction of suspended particles are investigated using a computational fluid dynamics (CFD) model with the k-$\varepsilon$ turbulence closure scheme based on the renormalization group (RNG) theory. Twelve numerical experiments with different meteorological and reclaiming conditions are performed. For identifying the meteorological characteristics of the target area and providing the inflow conditions of the CFD model, the observed data from the automatic weather station (AWS) near the target area is analyzed. Complicated flow patterns such as flow distortion, horse-shoe vortex, recirculation zone, and channeling flow appeared due to the topography and buildings in the domain. Specially, the flow characteristics around the reclamation area are affected by the reclaiming height, reclaiming size and windbreak height. Reclaiming height affected the wind speed above the reclaiming area. Windbreak induces more complicated flow patterns around the reclaiming area as well as within the reclaiming area. In front of the windbreak, flow is distorted as it impinges on the windbreak. As a result, upward flow is generated there. Behind the windbreak, a secondary circulation, so called, a recirculation zone is generated and flow is reattached at the end of the recirculation zone (reattachment point). At the lower part of the recirculation zone, there is a reverse flow toward the windbreak. Flow passing to the reattachment point starts to be recovered. Total amounts of suspended particles are calculated using the frictional and threshold frictional velocities, erosion potential function, and the number of surface disturbance. In the case of a 10 m-reclaiming and northerly wind, the amount of suspended particles is largest. In the presence of 5 m windbreak, the friction velocity above the reclaiming area is largely reduced. As a result, the total amount of the suspended particles largely decreases, compared to the case with the same reclaiming and meteorological conditions except for the windbreak The calculated suspended particle amounts are used as the emission rate of the dispersion model simulations and the dispersion characteristics of the suspended particles are analyzed.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.6
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• pp.544-549
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• 2009

Failure to use effective methods of reduction, fixation and immobilization may lead to osteomyelitis with the exposed necrotic bone, as the overzealous use of transosseous wires & plates that devascularizes bone segments in the compound comminuted fractures of mandible. Once osteomyelitis secondary to fractures has become established, intermaxillary fixation should be instituted as early as possible. Fixation enhances patient comfort and hinders ingress of microorganisms and debris by movement of bone fragments. Teeth and foreign materials that are in the line of fracture should be removed and initial debridement performed at the earliest possible time. Grossly necrotic bone should be excised as early as possible ; no attempt should be made to create soft tissue flaps to achieve closure over exposed bone. The key to treatment of chronic osteomyelitis of the mandible is adequate and prolonged soft tissue drainage. If good soft tissue drainage is provided over a long period, sequestration of infected bone followed by regeneration or fibrous tissue replacement will occur so that appearance and function are not seriously altered. Localization and sequestration of infected mandible are far better performed by natural mechanism of homeostasis than by cutting across involved bone with a cosmetic or functional defect. As natural host defenses and conservative therapy begin to be effective, the process may become chronic, inflammation regresses, granulation tissue is formed, and new blood vessels cause lysis of bone, thus separating fragments of necrotic bone(sequestra) from viable bone. The sequestra may be isolated by a bed of granulation tissue, encased in a sheath of new bone(involucrum), and removed easily with pincettes. This is a case report of the long-term conservative drainage care in osteomyelitis associated with mandibular fractures.

• Journal of the Korea Concrete Institute
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• v.15 no.6
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• pp.802-810
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• 2003

In this paper, the modified singular fracture process zone (S-FPZ) model is proposed to consider variation of a fracture criterion for continuous crack propagation in concrete. The fracture properties of the proposed fracture model are strain energy release rate at a micro-crack tip and crack closure stress (CCS) versus crack opening displacement (COD) relationship in the FPZ. The proposed model can simulate the estimated fracture energy of experimental results. The analysis results of the experimental data shows that specimen geometry and loading condition did not affect the CCS-COD relation. But the strain energy release rate is a function of not only specimen geometry but also crack extension. Until 25 mm crack extension, the strain energy release rate is a constant minimum value, and then it increased linearly to the maximum value. The maximum fracture criterion occurred at the peak load for an large size specimen. The fracture criterion remains the maximum value after the peak load. The variation of the fracture criterion is caused by micro-cracking and micro-crack localizing. The fracture criterion of strain energy release rate can simply be the size effect of concrete fracture, and it can be used to quantify the micro-tracking and micro-crack localizing behaviors of concrete.

• Journal of Chest Surgery
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• v.23 no.4
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• pp.617-621
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• 1990

A heart supplies blood of about 15, 000 liters to each human organ in a day. A normal function of heart valves is necessary to accomplish these enormous work of heart. The disease of heart valve develops to a narrowness of a closure, resulting in an abnormal circulation of blood. In an attempt to eliminate the affliction of heart valves, the operative method to replace with artificial heart valves has developed and saved numerous patients over past 30 years. This replacement operation has been performed since early 1960`s in Korea, but all the artificial heart valves used are imported from abroad with very high costs until recent years. New artificial heart valves have been developed in Korea Advanced Institute of Science and Technology since early 1980`s. The first developed valve was designed with a free-floating pyrolytic carbon disk that is suspended in a titanium cage. The design of the valve was tested in vitro, and in animals in 1987. The results from this study was that the eccentrically placed struts creates a major and minor orifice when the disc opens and stagnation of flow in the area of the minor orifice has led to valve thrombosis. In this work, the design of the valve was changed from a single - leaflet valve to double - leaflet one in order to resolve the problems observed in the first - year tests. Morphological and hemodynamic studies were made for the newly designed valves through the in vitro and in vivo tests. The design and partial materials of the artificial heart valve was improved comparing with first - year`s model. The disc in the valve was modified from single - leaflet to bi - leaflet, and the material of the cage was changed from titanium metal to silicon - alloyed pyrolytic carbon. A test was made for the valve in order to examine its mechanical performance and stability. Morphological and hemodynamic studies were made for the valve that had been implanted in tricuspid position of mongrel dogs. All the test animals were observed just before the deaths. A new artificial heart valve was designed and fabricated in order to resolve the problems observed in the old model. The new valve was verified to have good stability and high resistance to wear through the performance tests. The hemodynamic properties of the valve after implantation were also estimated to be good in animal tests. Therefore, the results suggest that the newly designed valve in this work has a good quality in view of the biocompatibility. However, valve thrombosis on valve leaflets and annulus were found. This morphological findings were in accordance with results of surface polishing status studies, indicating that a technique of fine polishing of the surface is necessary to develop a valve with higher quality and performance.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.2
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• pp.285-294
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• 1991

The human temporomandibular joint as a ginglymoarthrodial one has much in common with the other synovial joints of the body, but it does possess an unique charachteristic in that it must accomodate the various occlusal relations of dentition during an end point of closure. For that reason, the movement of the condyle in the temporomandibular joint is susceptible to influences from the nature of occlusion. Undue loading to the temporomandibular joint can be applied on the occasion of premature contacts in centric relation, balancing side interferences, change of occlusal surfaces due to excessive attrition, loss of tooth. Such occlusal disharmonies in association with the systemic and emotional factors may give rise to the temporomandibular disorder. On the other hand, the changes of occlusal patterns in the growing body can also have an effect on the growth of the temporomandibular joint through the alterations of functional stresses. The purpose of this study was to observe histopathologic response of the temporomandibular joint in unilateral chewing on one side exclusively for 10 months. Three dogs showing normal masticatory function were chosen. One dog aged about 12 months was for control, two dogs for experimental specimens were about 12 and 18 months old respectively. For chewing on the left side only, unilateral lower right premolar and molar were extracted in two experimental specimens. And then three dogs were sacrificed 10 months later. Frontal histologic sectioning of joints were done for the observation of the effects of one-side chewing. 24 specimens from three dogs were obtained and fixed in 10% formalin and routinly processed with H-E staining for histologic examination. The light microscopic findings were interpretated as follows: 1. Experimental specimen 1 aged about 22 months: In comparison with control and right non-chewing side, the proliferative and hypertrophic zone were increased at the mesial and lateral part of left chewing side condyle. There was no change of the articular tissue of temporal bone. 2. Experimental specimen 2 aged about 28 months: The articular tissues of adult joint were observed. The differences between the chewing and non-chewing side were not seen in the articular tissues of condyle and temporal bone.

• Biomedical Science Letters
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• v.6 no.2
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• pp.119-129
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• 2000

The skin is an organ that has many important roles, including protection against infection, regulation of temperature and fluid loss, and sensory function. Injury to the skin, wound repair normally involves: (1) balanced activity of inflammation, (2) the re-epithelial phase and (3) the matrix formation of remodeling phase. Thus, skin wound healing is a finely controlled biological process involving a series of complex cellular interactions. Laser therapy is being implemented with increasing frequency in medicine. Low intensity laser is one that is capable of producing an energy density so low that any biologic alterations are the result of direct irradiation effect, not thermal events. This study was designed to evaluate the efficacy of low intensity laser therapy on skin wound healing in rabbits. A total of 10 male rabbits (New Zealand White Rabbit), age 8 weeks were used. Skin wound were surgically created dorso-lateral on the flank of 10 rabbits (2$\times$2 cm/damage areas). The experimental animals were treated with 5Hz (830 nm wave length) low-intensity laser (MILTA-01 Model) daily for 10 min (1.6 J/$cm^2$) for 12 days. Control animals were sham treated with the laser head. Laser irradiation animals showed a complete remodeling of the epithelial layer, a positive repair of connective tissues, and enhanced the wound closure rate over time as compared to the control animals. Especially, laser irradiation groups improved fibroblast activity, cellular content, granulation tissue formation, and collagen deposition which is resulted in improving the tensile strength of the wound. These findings suggest that laser photostimulation could accelerate healing of open wound in rabbits, and may be benefit in the treatment of open wound, including decubitis ulcers.