• Proceedings of the Korean Fiber Society Conference
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• 1990.06b
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• pp.8-8
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• 1990

A new method for the graft polymerization of acrylonitrile onto starch is presented. Graft polymerization of acrylonitrile onto starch and the subsequent hydrolysis in sodium hydroxide solution to prepare absorbents is well known. This process has been utilized to produce the commercial product, Super Slurper. In a typical batch process, ~5% starch in water mixture is gelatinized at $95^{\circ}C$ under stirring for 1 hour then cooled to room temperature. The graft polymerization itself is carried out for approximately 2 hours at $25~30^{\circ}C$ on the gelatinized starch by eerie ion initiation. In this study, graft polymerization of acrylonitrile onto starch via a reactive extrusion process which is a continuous, efficient process is described. Initial concentration of starch in water is 35% and the reaction temperatures are between $50~80^{\circ}C$. However, the most significant difference in the reactive extrusion process is the short time in which the graft polymerization takes place. Preliminary results on the properties of graft polymerization products obtained from the reactive extrusion process are compared to those obtained from the batch process as well as the absorbency of the hydrolyzed samples. Absorbent material has also been prepared by sequential grafting and saponification in the extruder followed by a 2 hour heat treatment of the extrudate in an air circulated oven at $100^{\circ}C$.

• Archives of Craniofacial Surgery
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• v.20 no.5
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• pp.319-323
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• 2019

Cochlear implant extrusion, which is a common complication of cochlear implants, is generally repaired by a well visualized soft-tissue flap. A 61-year-old female patient with a medical history of schizophrenia who had a skin ulcer that caused cochlear implant extrusion, but that would be a stronger statement was referred to our department for removal of the implant and reconstruction of the resultant scalp defect. Accordingly, the broad defect was covered via rotation of a temporoparietal fascia flap (TPFF) using the superficial temporal artery, with the pedicle in the preauricular region as the pivot point. Coverage of TPFF was achieved with a split-thickness skin graft using the scalp as the donor site, which led to a quick recovery after the operation and satisfactory results in terms of aesthetics. This case suggests that a TPFF might be used as a flexible flap with low donor site morbidity for reconstructing cases of cochlear implant extrusion accompanied by a large full-layer scalp defect.

• Journal of the Korean Arthroscopy Society
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• v.17 no.1
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• pp.76-78
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• 2013

The meniscus is considered "extruded" when it extends beyond the tibial margins more than 3 mm in a coronal view of magnetic resonance imaging (MRI). However, identifying the meniscal extrusion intraoperatively may be difficult because of the simple fact that most of the arthroscopic procedures are done in knee flexion position while follow up MRI studies area taken at knee extension position. Here, we demonstrate the arthroscopic technique for evaluating the meniscal extrusion.

• Journal of Korean Neurosurgical Society
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• v.44 no.4
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• pp.259-261
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• 2008

We present a case of delayed oral extrusion of a screw after anterior cervical interbody fusion in a 68-year-old man with osteoporosis. Fifteen months earlier, he had undergone C5 corpectomy and anterior cervical interbody fusion at C4-6 for multiple spinal stenoses. The patient was nearly asymptomatic, except for a foreign body sensation in his throat. We conclude that the use of a mesh graft or other instrument in elderly patients and those with osteoporosis or problematic bone quality should be considered carefully and that if surgery were to be performed, periodic postoperative follow-up evaluations are mandatory.

• Proceedings of the Korean Society of Rheology Conference
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• 2006.06a
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• pp.157-160
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• 2006

• Journal of Periodontal and Implant Science
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• v.37 no.2
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• pp.287-295
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• 2007

As a general treatment modality of subgingival tooth defect in aethetic area, implant or crown and bridge therapy after extraction of affected tooth can be used. But as more conservative treatment, crown lengthening can be considered and not to lose periodontal attachment and impair aethetic appearance, surgical extrusion can be considered as a treatment of choice. In this case report, 3 cases of surgical extrusion was represented and appropriate time for initiation of endodontic treatment according to the post-surgical tooth mobility was investigated. In 8 patient who has subgingival tooth defect in aethetic area, intracrevicular incision is performed and flap was reflected with care not to injure interproximal papillae. With forcep or periotome, tooth was luxated and sutured in properely extruded position according to biologic width with or without $180^{\circ}$ rotation. 8 cases show favorable short and long term results. In some cases, surgical extrusion with $180^{\circ}$ rotation can minimized extent of extrusion and semi-rigid fixation without apical bone graft seems to secure good prognosis. In 8 cases, endodontic treatment started about 3 weeks after surgery. This time corresponds with the moment when mobility of extruded tooth became 1 degree and this results concide with other previous reports. If it is done on adequate case selection and surgical technique, surgical extrusion seems to be a good treatment modalilty to replace the implant restoration in aethetic area.

• Archives of Plastic Surgery
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• v.38 no.1
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• pp.53-62
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• 2011

Purpose: Even though Augmentation rhinoplasty is very popular surgical procedure, it is not easy to obtain ideal materials for augmentation. Many different synthetic materials are used but frequent complications are seen such as infection, extrusion, deform, and dislocation. Autologous tissues were used for augmentation rhinoplasty. We used dermofat graft and fat injection in augmentation rhinoplasty minimizing these problems. Methods: From 2006 to 2009, we used autologous tissues in augmentation rhinoplasty in 40 patients, 20 patients with dermofat graft and other 20 patients were treated with fat injection only. Dermofats were harvested from sacral area. gluteal fold, groin and preexisting scar tissue. Dermofats were inserted with small stab wound and fat tissues were injected as Coleman's technique. The patients were followed up 6 months to 5 years. Results: Most of the patients were satisfied in shape and height the nose. Early complications such as hematoma, infection and seroma were not found. Secondary fat injection was performed in 3 patients (15%) of dermofat graft group instead of 7 patients (35%) of fat injection only group. Conclusion: We obtained satisfactory results in augmentation rhinoplasty with dermofat graft and fat injection. Secondary fat injections were more often in fat injection group than dermofat graft group. Dermofat graft and fat injection could be another alternative technique for augmentation rhinoplasty and fat injection could be a secondary adjunctive treatment for undercorrection due to absorption.

• Journal of Korean Neurosurgical Society
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• v.29 no.8
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• pp.1043-1049
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• 2000

Objective : This study was undertaken to evaluate the availability of allogenic fibular bone graft filled with autogenous bone dust in anterior cervical fusion after cervical discectomy. Methods : During a 4-year period(1995-1998), twenty four cases of anterior cervical fusion after discectomy were performed with fibular allograft filled with autogenous bone dust in degenerative cervical disease. We used freeze-dried fibular allograft and autogenous bone dust. Autogenous bone dust obtained from spondylotic spurs, osteophytes, and during foraminotomy. Cervical plating system was done at 8 patients. 5 patients were 1 level and 3 patients were 2 levels. All patients were routinely evaluated after surgery at 2 weeks, 1 month, 3 months, 5 months and 12 months. Mean follow-up period was 21months. Results : Eighty eight percent of the patients were found to have excellent or good clinical results. Radiographic follow-up revealed that 92% of the patients obtained complete or partial union by 5 months after surgery. One patient had graft extrusion immediately after surgery and had the graft reinserted. Two patients had longitudinal graft fractures. There were no graft related complications. Conclusion : Fibular allograft filled with autogenous bone dust for cervical interbody fusion after discectomy is an ideal graft material by showing obvious benefits of good fusion rate and elimination of donor site complications. And also we were able to obtain satisfactory clinical outcome.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.369-369
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• 2006

Compatibilizers contribute to many processes in polymer industry, such as manufacturing polymer blends and composites. They are usually designed to be block or graft form which is combined in polar and non-polar parts in the first synthesis process level, for example, the general form of maleic anhydride (MA) as a compatiblizer is a grafted counterpart. However, the process of making the compatibilizer is related to the first synthesis level and it has some problems, such as high cost, poor processability, limitation on use and properties, and so on. So, in order to improve its poor processability and overcome the limitation on use, we developed compatibilizers which have various chemical forms by high intensity ultrasound and super critical fluid nitrogen in polymer melt reactive extrusion.

• Archives of Plastic Surgery
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• v.37 no.3
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• pp.259-264
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• 2010

Purpose: Most surgeons have used autogenous cartilage for columella strut graft. But the supply of autogenous cartilage is often limited. So, this study is to investigate the usefulness of biodegradable plate as columella strut material. Methods: We studied 19 patients who have secondary cleft nasal deformity. Patients were divided into two groups. Group A patients who were not closed their growth plate underwent columella strut graft only with biodegradable plate through endonasal approach. The biodegradable plate was inserted between nasal tip and anterior nasal spine. Group B patients were closed their growth plate. They had an operation for columella strut graft with biodegradable plate fixed with autogenous conchal cartilage. If nasal tip projection was insufficient, we performed additionally onlay graft on nasal tip with autogenous soft tissue or remnant cartilage. Results: As a result of mean 14 months follow-up, we achieved a good nasal tip projection, narrowing of interalar distance and symmetrical nostril shape. No specific complications were reported except 2 cases, which were the extrusion of biodegradable plate into the nasal cavity and Staphylococcus aureus infection. Conclusion: The columella strut graft using biodegradable plate is simple and effective method. Biodegradable plate can be a good substitute for columella strut in patients who can not use autogenous cartilages.