• Journal of Korean Foot and Ankle Society
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• v.22 no.4
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• pp.181-183
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• 2018

Hallux valgus is a deformity that causes pain in the first metatarsophalangeal joint. Surgical methods are quite diverse and a range of osteotomies are used at the proximal and distal part of the metatarsal bone and proximal phalange. Fixation methods, such as plate, screw, K-wire, and others have been used in various ways. The fixation device is often removed with various side effects due to the fixation devices. In the case of instruments that are absorbed in vivo, these procedures are not necessary to remove and there is an advantage of not performing the second operation. Three patients were treated, in which a proximal chevron osteotomy was used with a bioabsorbable screw (K-$MET^{TM}$; U&I Corporation).

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.04a
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• pp.23-26
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• 2003

Solid-state extrusion technique was employed for the improvement of mechanical properties of polylactic acid (PLLA) widely used as biodegradable internal fixation devices currently. Cylindrical billets were machined out from the vacuum compression-molded PLLA to have various diameters, and solid-state extrusion of the billets was performed at various drawing rates and at the extrusion temperature of $130^{\circ}C$. Throughout the whole processes the decrease in molecular weight was significantly suppressed to be about $10\%$. Flexural modulus and strength of PLLA increased up to 8.3 GPa and 221 MPa, respectively. Studies on the orientation and crystallinity of extruded PLLA could reveal the effects of billet morphology, draw ratio, and drawing rate on the flexural strengths of PLLA.

• Journal of Korean Neurosurgical Society
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• v.29 no.7
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• pp.940-944
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• 2000

The giant-cell tumor is uncommon. It occurs in the long bones and vertebral localization is much less common, particularly in thoracic spine. We present a case of a 37-year-old man suffering from severe back pain. Affected vertebral bodies were removed by transthoracic approach and the spine was reconstructed with iliac bone autografts and internal fixation device(Kaneda) between T 8 and T 11. Histologoical diagnosis was giant-cell tumor, and pertinent literature was reviewed.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.143-144
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• 2013

Unit module system produce units in the factory and assemble in the field. This unit module system has advantages of shortening the process of construction. However, it is still in the early research related to setting the unit module which is transported by truck to the field. Therefore, when transporting the unit module, this goal of study develops fixed devices. And suggesting device were performed that simulations analyzed maximum stress and assessed the safety.

• Archives of Reconstructive Microsurgery
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• v.24 no.1
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• pp.20-23
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• 2015

Despite increased utilization of microvascular anastomotic coupler (MAC) devices, the consequences have yet to be fully explored in terms of vascular regeneration. Removal of an exposed venous coupler is described herein, documenting normal circulatory flow through the remodeled site of application. A 25-year-old man who underwent open reduction and rigid fixation elsewhere for traumatic calcaneal fracture ultimately presented with a necrotic postoperative wound. The debrided defect was treated by free thigh perforator flap, incorporating a MAC device. Three months later, the flap remained viable, but the MAC itself was exposed. Structural integrity of the vessel and blood flow were sustained as the device was carefully removed, confirming true vascular remodeling in this example of MAC usage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.398-404
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• 2017

The aim of this study was to determine the effect of a non-elastic fixation belt on the balance ability and fall prevention in elderly women. Elderly women experience reduced balance ability and an increased risk of falls due to a weakening of the surrounding sacroiliac joint and pelvic muscles during childbirth and menopause. On the other hand, specific studies are still needed. The subjects were allocated randomly to two groups: control (n=20) and experimental (n=20). The experimental group used a non-elastic fixation belt, whereas the control group had no fixation belt. The balance ability and the fall index were measured in all subjects using a balance measurement device, and the low abdominal muscle thickness was determined in the experimental group using ultrasound imaging for the exact application of the non-elastic fixation belt. The following statistical analysis was performed: an independent t-test for the general characteristics of the subjects, $2{\times}2$ analysis of variance with repeated measures for the balance and fall index score, and a paired t-test for the abdominal muscle thickness. The group ${\times}$ time interaction effect showed significant improvement in the General Stability Index (F1,38=47.24, p=0.001), Fourier Harmony Index (F1,38=88.83, p=0.001), Weight Distribution Index (F1,38=50.21, p=0.001), and Fall Index (F1,38=21.59, p=0.001). The thicknesses of the transverse abdominal (p=0.001) and internal oblique (p=0.001) muscles were increased significantly in the experimental group after using the non-elastic fixation belt. Overall, the application of a non-elastic fixation belt could be effective in improving the balance ability and fall prevention in elderly women.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.1
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• pp.85-92
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• 2005

Reconstruction of defect in the anterior part of the maxilla to enable implant placement or prothesis is a complicated treatment due to the anatomical position and lack of soft tissues. Two cases are presented in which autogenous iliac PMCB(particulate marrow and cancellous bone) with titanium mesh were used for premaxilla reconstruction and alveolar bone repair of the anterior maxillas prior to denture and implants fixation respectively. Cancellous bone from the anterior iliac crest was compressed and placed against a titanium mesh fixed to the bone of palate in a patient with severe defect of the anterior maxilla. There were no problem in the healing, and the anterior maxillas of two patients had increased height and width during the initial healing and remodeling. The clinical reports describe the use of titanium mesh for reconstruction of premaxilla. Autogenous bone grafts were harvested from the iliac crest and were loaded on a titanium mesh that were left in the patient's maxilla for 6 months before they were removed respectively. The radiographic analysis demonstrated that a 10mm vertical ridge augmentation had been achieved. In guided bone regeneration, the quantity of bone regenerated under the barrier has been demonstrated to be directly related to the amount of the space under the membrane. This space can diminish as a result of membrane collapse. To avoid this problem which involved the use of a titanium mesh barrier to protect the regenerating tissues and to achieve a rigid fixation of the bone segments, were used in association with autologous bone in 2 cases. The aim of this study was to evaluate the capability of a configured titanium mesh to serve as a mechanical and biologic device for restoring a vertically defected premaxilla.

• Journal of Korean Foot and Ankle Society
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• v.13 no.1
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• pp.80-84
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• 2009

Purpose: The purpose of this article is to assess the efficacy of a bioabsorbable polylactide (PLA) plate and screw for treating injuries of ankle fractures. Materials and Methods: 24 patients who underwent an open reduction and internal fixation operation for ankle fractures from July 2005 to March 2007 were enrolled into the study. There were 15 men and 9 women. The average age of the patients was 44 years and the average follow-up period was 16 years and two months (16.2 months). All cases were divided into low grade fracture patient (11) who belongs in type A and B of Danis-Weber classification and high grade fracture patient (13) who belongs in type C1, C2 of Danis-Weber classification, and each groups were analyzed by clinical (Meyer score) and radiological finding at the time of their last follow-up evaluation. Results: The clinical results according to Meyer scoring system, showed that all patient with low grade fracture had good to excellent result, but only 54% of patient with high grade fracture had good to excellent result. According to Cedell's radiologic finding, there were 91% cases above fair in low grade fracture. But there were 62% of patient above fair result in high grade fracture, the reduction losses were seen in 38% of patient with high grade fracture. Conclusion: Bioabsorbable PLA plate and screw is good internal fixation device which doesn't have additional operation for removal of implant because of slow absorption within the human body. It showed sufficient strength for acquisition and maintenance of reduction in low grade fracture, but need attention to use because of many cases of reduction loss in high grade fracture. So, it seems to be safe and effective when used in heeling of low grade fracture under considering about type of fracture sufficiently.

• Archives of Plastic Surgery
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• v.34 no.1
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• pp.123-127
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• 2007

Purpose: Rigid external distraction(RED) is a highly effective technique for correction of maxillary hypoplasia in patients with cleft or syndromic craniosynostosis. Despite many advantages of RED, it also has the problem of relapse as the conventional advancement surgery. Bicoronal approach, that is the common approach to gain access to the craniofacial skeleton, had some morbidity, such as hair loss, sensory loss, wide scar and temporal hollowing. We present our clinical experience of RED distraction with minimal invasive approach and early rigid fixation to overcome these disadvantages. Methods: A 27-year-old female patient with Crouzon's disease underwent Le Fort III osteotomy and RED device application through the minimal invasive direct skin incisions. After the latent period of 5 days, distraction was undertaken until proper convexity and advancement were obtained. During the rigid retention period, inflammation occurred on the right cheek, and proper conservative managements were done including continuous irrigation. To maintain the stability of distraction, early rigid fixation was undertaken on the osteotomy sites through another skin incisions. Preoperative and postoperative orthodontic treatments were performed. Serial photographs and cephalometric radiographs were obtained preoperatively, after distraction and 6 months after distraction. Results: The cephalometric analysis demonstrated postoperatively significant advancement of the maxilla and improvement of facial convexity. After 6-month follow-up period, the maxilla was stable in the sagittal plane and no relapse was found. Facial scars were not noticeable and other deformity and morbidity did not occur. Conclusion: This effective and stable technique will be a good alternative for the patients who need large amount of distraction and for adult patients with severe maxillary hypoplasia or syndromic craniosynostosis.

• Journal of the Semiconductor & Display Technology
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• v.15 no.3
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• pp.72-77
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• 2016

As the semiconductor production technology has gradually developed and intra-market competition has grown fiercer, the caliber of Si Wafer for semiconductor production has increased as well. And semiconductors have become integrated with higher density. Presently the Si Wafer caliber has reached up to 450 mm and relevant production technology has been advanced together. Electrostatic chuck is an important device utilized not only for the Wafer transport and fixation but also for the heat treatment process based on plasma. To effectively control the high calories generated by plasma, it employs a refrigerant-based cooling method. Amid the enlarging Si Wafers and semiconductor device integration, effective temperature control is essential. Therefore, uniformed temperature distribution in the electrostatic chuck is a key factor determining its performance. In this study, the form of refrigerant flow channel will be investigated for uniformed temperature distribution in electrostatic chuck.