• Archives of Plastic Surgery
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• 제46권1호
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• pp.23-33
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• 2019

Background Venous malformations (VMs) are a common type of vascular malformation. However, their causes and management remain unclear, and few studies specific to VMs of the head and neck have been reported. This study describes our experiences with VMs of the head and neck. Methods This retrospective study included 82 patients who underwent treatment for head and neck VMs, among 222 who visited our vascular anomalies center. Medical records between 2003 and 2016 were reviewed to identify common features in the diagnosis and treatment. The diagnosis of suspected head and neck VMs was based on the results of imaging studies or biopsies, and the VMs were analyzed based on magnetic resonance imaging, computed tomography, and Doppler sonography findings. Results VMs were slightly more common in female patients (59.8%), and 45.1% of patients developed initial symptoms at the age of 10 or younger. Lesions were slightly more common on the right side (47.3%). The main sites involved were the cheek (27.7%) and lip area (25.5%). The muscle layer was commonly involved, in 98.7% of cases. Small lesions less than 5 cm in diameter accounted for 60.8% of cases, and well-defined types were slightly more prevalent at 55.4%. Improvement was observed in 77.1% of treated patients. Conclusions Early and accurate diagnosis and appropriate treatment according to individual symptoms are important for successful treatment of VMs. If treatment is delayed, the lesions can worsen, or recurrence becomes more likely. Therefore, VMs require a multidisciplinary approach for early and accurate diagnosis.

• 대한두개안면성형외과학회지
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• 제23권5호
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• pp.220-227
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• 2022

Background: Frontal sinus fractures are relatively rare. Their surgical management significantly differs depending on whether the posterior wall is invaded and the clinical features vary. A bicoronal incision or endoscopic approach can be used. However, the minimally invasive approach has been attracting attention, leading us to introduce a simple and effective surgical method using multiple-threaded Kirschner wires. Methods: All patients had isolated anterior wall fractures without nasofrontal duct impairment. The depth from the skin to the posterior wall was measured using computed tomography to prevent injury. The edge of the bone segment on the skin was marked, a threaded Kirschner wire was inserted into the center of the bone segment, and multiple Kirschner wires were gently reduced simultaneously. Results: Surgery was performed on 11 patients. Among them, seven patients required additional support for appropriate fracture reduction. Therefore, a periosteal elevator was used as an adjunct through a small sub-brow incision because the reduction was incomplete with the Kirschner wire alone. The reduction results were confirmed using facial bone computed tomography 1 to 3 days postoperatively. The follow-up period was 3 to 12 months. Conclusion: The patients had no complications and were satisfied with the surgical results. Here we demonstrated an easy and successful procedure to reduce a pure anterior wall frontal sinus fracture via non-invasive threaded Kirschner wire reduction.

• Earthquakes and Structures
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• 제24권1호
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• pp.11-20
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• 2023

"Performance-based design (PBD)" is based on designing a structure with choosing a performance target under design criteria to increase the structure's resistance against earthquake effect. The plastic hinge formation is determined as one of the fundamental data in finite elements nonlinear analysis to distinguish the condition of the structure where more significant potential damage could occur. If the number of plastic hinges in the structure is increased, the total horizontal load capability of the structure is increased, also. Theoretically, when the number of plastic hinges of the plane frame structure reaches "the degree of hyperstaticity plus one", the structure will reach the capability of the largest ultimate horizontal load. As the number of plastic hinges to be formed in the structure increases towards the theoretical plastic hinge number (TPHN), the total horizontal load capability of the structure increases, proportionally. In the previous studies of the authors, the features of examining the new performance criteria were revealed and it was formulated as follows "Increase the total number of plastic hinges to be formed in the structure to the number of theoretical plastic hinges as much as possible and keep the structure below its targeted performance with related codes". With this new performance criterion, it has been shown that the total lateral load capability of the building is higher than the total lateral load capability obtained with the traditional PBD method by the FEMA 440 and FEMA 356 design guides. In this study, PBD analysis results of structures with frame carrier systems are presented in the light of the Turkey Building Earthquake Code 2019. As a result of this study, it has been shown that the load capability of the structure in the examples of structures with frame carrier system increases by using this new performance criterion presented, compared to the results of the examination with the traditional PBD method in TBEC 2019.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.231-233
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• 2005

In this paper, we discuss the potential applications for electronic systems on flexible substrates. The barriers to the successful development of commercial markets are analyzed. For each promising application, the critical technical features are identified. Ways to bridge the gap between research and commercialization are suggested.

• Archives of Plastic Surgery
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• 제42권5호
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• pp.567-571
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• 2015

Background Bariatric surgeries performed in the USA has increased twelve-fold in the past two decades. The effects of rapid weight loss on facial features has not been previously studied. We hypothesized that bariatric surgery will mimic the effects of aging thus giving the patient an older and less attractive appearance. Methods Consecutive patients were enrolled from the bariatric surgical clinic at our institution. Pre and post weight loss photographs were taken and used to generate two surveys. The surveys were distributed through social media to assess the difference between the preoperative and postoperative facial photos, in terms of patients' perceived age and overall attractiveness. 102 respondents completed the first survey and 95 respondents completed the second survey. Results Of the 14 patients, five showed statistically significant change in perceived age (three more likely to be perceived older and two less likely to be perceived older). The patients were assessed to be more attractive postoperatively, which showed statistical significance. Conclusions Weight loss does affect facial aesthetics. Mild weight loss is perceived by survey respondents to give the appearance of a younger but less attractive patient, while substantial weight loss is perceived to give the appearance of an older but more attractive patient.

• Archives of Plastic Surgery
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• 제38권4호
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• pp.465-471
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• 2011

Purpose: Blepharoptosis is often associated with telecanthus and the presence of epicanthal fold in telecanthus is one of unique features in Asian eyelids. The purpose of this article is to define telecanthus and pseudotelecanthus, and to determine optimal surgical procedure depending on classification of telecanthus. Methods: Among 187 patients with blepharoptosis who had the advancement procedure of the Muller's musclelevator aponeurosis composite flap for ptosis, 55 patients underwent Flowers' split V-W plasty concomitantly with shortening the medial canthal tendon for correction of telecanthus from September 2003 to January 2011. Among them, 52 patients were followed up for 16 months. We newly defined telecanthus because Mustarde ratio is inaccurate to measure in certain cases and then made a definition of pseudotelecanthus. Besides, we also classified telecanthus into mild, moderate and severe types based on its severity. Results: Telecanthus is defined when the ICD (inner canthal distance) is greater than 110% of normal ICD. Pseudotelecanthus is a telecanthus like a wide skin bridge formed between the eyes because of the epicanthal fold in the normal ICD. Flowers' split V-W plasty combined with shortening medial canthal tendon was very effective in mild and moderate telecanthus with almost invisible scar and no recurrence occurring. In severe types, however, it showed high incidence (28%) of incomplete correction of telecanthus. Conclusion: New definition of telecanthus can be easily applied to any case and we think the classification of telecanthus is useful to select an appropriate operative procedure. Split V-W plasty with shortening of medial canthal tendon is a very effective procedure in mild and moderate telecanthus. Besides, it is also effective in improving the treatment outcomes of ptosis in cases of blepharoptosis associated with telecanthus.

• Archives of Plastic Surgery
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• 제37권6호
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• pp.726-731
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• 2010

Purpose: Autologous fat grafting is a popular procedure for the correction of the soft tissue depression and deformity. But there are several issues required to be carefully considered in relation to this procedure, mainly about the unpredictability and the low survival rate of the grafted fat due to absorption and partial necrosis. Sphingosine-1-phosphate (S1P) is a lysophospholipid mediator that has been proposed to promote angiogenesis and to regulate the differentiation of adipose derived stromal cells (ASCs). In this study, we analyzed the viability of the grafted fat tissue mixed with S1P into each 12 nude mice (cann.cg-fox1nu/crlori) compared to the group of mice grafted fat tissue only. Methods: Human aspirated fat was grafted subcutaneously into the backs of 8-week-old nude mice with or without S1P. Eight weeks later, the grafted fat was harvested and the weight and volume were checked. The fat was stained with hematoxylin-eosin and 4',6-diamidino-2-phenylindole. Results: S1P group weighed significantly more than the control group (p=0.009), and the volume from the S1P group was considerably larger than that of the control group (p=0.004) either. In histological features, the surviving layer of the S1P group was thicker than the control group and microvasculature appeared to be prominent in the S1P group, especially in the outer layers. Conclusion: These findings suggest that S1P plays a vital role in the soft tissue augmentation, potentially providing a novel point of the control in adipose tissue for microfat graft.

• Archives of Plastic Surgery
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• 제46권5호
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• pp.414-420
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• 2019

Background Congenital muscular torticollis (CMT) is characterized by persistent head tilt toward the affected side. No consensus exists regarding the cause of this disorder. In this study, we analyzed various clinical factors in patients with CMT who were treated with surgical release. This analysis enabled us to identify potential causative factors of CMT and to establish a basis for surgical interventions. Methods In total, 584 patients who underwent surgical intervention for CMT from October 2007 to December 2016 were included in this study. Their demographic characteristics, birthrelated factors, and clinical features were analyzed. Results Data from 525 patients were analyzed in this study after exclusion of those with insufficient information. Before birth, 31 patients (5.9%) were diagnosed with oligohydramnios, and 87 (16.6%) had a breech presentation. Seven (1.3%) cases of clavicle fracture and two (0.4%) cases of cephalohematoma were noted at birth. Before surgery, 397 patients (75.6%) underwent physiotherapy and 128 patients (24.4%) did not. The duration of physiotherapy ranged from 1 to 50 months (average, 6 months). Conclusions Our study shows that 16.6% of the CMT patients presented in the breech position, which is a much higher rate than that observed in the general population (3%-4%). We hypothesize that being in the breech position as a fetus appears to exert a significant influence on shortening and fibrosis of the sternocleidomastoid muscle.

• Tribology and Lubricants
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• 제39권6호
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• pp.235-243
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• 2023

This paper presents the fabrication process of water-lubricated plastic bearings. Plastic bearings require good mechanical properties and tribological properties as well as elasticity and shock resistance, especially when lubricated in dirty water conditions. In this study, sleeve-type plastic bearings are produced by winding a prepreg sheet, which primary contains nitrile rubber (NBR)-modified epoxy, self-lubricating fillers, and various types of lattice-structured reinforcing fibers such as carbon, Aramid, and polyethylene terephthalate. A thermosetting epoxy is chemically modified with NBR to impart elasticity and low-friction characteristics in water conditions. Experimental investigations are conducted to examine the mechanical and tribological characteristics of the developed bearing materials, and the results are compared with the characteristics of a commercial plastic bearing (Thordon SXL), well known as a water-lubricated bearing. A Thordon bearing (mainly composed of polyurethane) exhibits an extremely low load-bearing capacity and is thus only suitable for medium loading (1~10MPa). The tribological characteristics of the test materials are evaluated through Falex block-on-ring (LFW-1) friction and wear tests. The results indicate that friction exhibited by the carbon-fiber-reinforced NBR-10wt.%-modified epoxy composite material, incorporated with the addition of 20wt.% UHMWPE and 6wt.% paraffin wax, is lower than that of the Thorden bearings, whereas its wear resistance surpass that of Thorden ones. Because of these features, the load carrying capacity of the fabricated composite (>10MPa) is higher than that of the Thorden bearings. These results confirm the applicability of water-lubricated plastic bearing materials developed in this study.

• Archives of Reconstructive Microsurgery
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• 제23권2호
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• pp.101-104
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• 2014

Reconstruction of soft tissue defects of the knee has always been a challenging task for plastic surgeons. Various reconstructive choices are available depending on the location, size, and depth of the defect relative to the knee joint. Defects on the knee joint have several characteristic features. The use of a free flap is preferred for reconstructions involving obliteration of large-cavity defects, but recipient pedicle isolation can be difficult because of the extent of the injury zone. Furthermore, the true defect during knee joint flexion is larger than during knee joint extension, and a durable flap is necessary for joint movement. We report for the first time on the use of pedicled perforator flaps for reconstruction of bilateral knee defects in a 76-year-old woman. The operative procedure required skeletonizing the perforators of an antero-lateral thigh flap and antero-medial thigh flap and rotating the flap in the defect. The patient returned to normal daily activity and had a full range of motion two months after the accident. The shorter operating time with decreased donor site morbidity and its durability make this flap a valuable alternative for soft tissue reconstruction of the knee.