• Archives of Plastic Surgery
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• v.34 no.1
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• pp.44-51
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• 2007

Purpose: Blow-out fracture is one of the most common fractures in facial trauma. It is diagnosed by Computed Tomography(CT) scan, which is considered as the most effective diagnostic tool. Since, the Picture Archiving Communication System(PACS) has been provided recently to many hospitals, doctors are more familiar with imaging software of PACS. Because this software has many useful measuring tools, doctors can measure orbital structure easily and make a plan for treatment with its data. Therefore, authors intended to analyze the data of orbital structure measured with PACS imaging software and evaluate its usefulness. Methods: The charts and CT images of 100 patients, which were 50 patients with medial wall fracture and 50 patients with floor fracture, were reviewed. Patients were selected by pre-determined criteria and their CT images were measured with image software of PACS. 'Extraocular muscle thickness', 'Defect ratio'(ratio of defect area to normal area) and 'Globe position index' were measured and analyzed statistically. Results: The thickness of inferior rectus muscle and medial rectus muscle was simultaneously increased in acute-stage of blow-out fracture. The medial rectus muscle was more thickened in medial wall fracture and inferior rectus was more thickened in floor fracture, respectively. In acute blow-out fracture, globe position is exophthalmic rather than enophthalmic. Especially in floor fracture, numerical value summed up thickness of all extraocular muscle is correlated to the defect ratio and globe position index. Conclusion: Clinicians can decide globe position or presume defect ratio in inferior wall fracture by measurement of CT image in acute blow-out fracture using PACS.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.67-69
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• 2006

Since magnesium alloy has a limited formability at room temperature, forming should be carried out at the elevated temperature. If the initial grain size is small, superplasticity could be expected over $400^{\circ}C$. Using superplastic behavior, blow forming can be used to overcome the low formability of Mg alloys. In the present study, the optimization of blow forming of AZ31 alloy at the elevated temperature was investigated. Finite element simulation was carried out and verified with the blow forming experiments.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.213-216
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• 2009

In order to see the flame behavior in the gas turbine combustor, combustion test was performed by using sector combustor. Ignition test with torch ignition system was carried out at the various combustor inlet velocity and air fuel ratio. Also, flame blow out limit was measured by changing fuel flow rate with fixed air mass flow rate. In the test results, stable ignition is possible at air excess ratio of 6 and this limit is gradually increased with combustor inlet air velocity. The minimum blow out limit is about 4 at 40 m/s of combustor inlet velocity. This blow out limit is also increased up to about 10 with increasing combustor inlet velocity.

• Archives of Craniofacial Surgery
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• v.11 no.1
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• pp.28-32
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• 2010

Purpose: In accordance with the increasing number of accidents caused by various reasons and recently developed fine diagnostic skills, the incidence of orbital blow-out fracture cases is increasing. As it causes complications, such as diplopia and enophthalmos, surgical reduction is commonly required. This article reports a retrospective series of 5 blow-out fracture cases that had unusual nerve injuries after reduction operations. We represents the clinical experiences about treatment process and follow-up. Methods: From January 2000 to August 2009, we treated total 705 blow-out fracture patients. Among them, there were 5 patients (0.71%) who suffered from postoperative neurologic complications. In all patients, the surgery was performed with open reduction with insertion of $Medpor^{(R)}$. Clinical symptoms and signs were a little different from each other. Results: In case 1, the diagnosis was oculomotor nerve palsy. The diagnosis of the case 2 was superior orbital fissure syndrome, case 3 was abducens nerve palsy, and case 4 was idiopathic supraorbital nerve injury. The last case 5 was diagnosed as optic neuropathy. Most of the causes were extended fracture, especially accompanied with medial and inferomedial orbital blow-out fracture. Extensive dissection and eyeball swelling, and over-retraction by assistants were also one of the causes. Immediately, we performed reexploration procedure to remove hematomas, decompress and check the incarceration. After that, we checked VEP (visual evoked potential), visual field test, electromyogram. With ophthalmologic test and followup CT, we can rule out the orbital apex syndrome. We gave $Salon^{(R)}$ (methylprednisolone, Hanlim pharmaceuticals) 500 mg twice a day for 3 days and let them bed rest. After that, we were tapering the high dose steroid with $Methylon^{(R)}$ (methylprednisolon 4 mg, Kunwha pharmaceuticals) 20 mg three times a day. Usually, it takes 1.2 months to recover from the nerve injury. Conclusion: According to the extent of nerve injury after the surgery of orbital blow-out fracture, the clinical symptoms were different. The most important point is to decide quickly whether the optic nerve injury occurred or not. Therefore, it is necess is to diagnose the nerve injury immediately, perform reexploration for decompression and use corticosteroid adequately. In other words, the early diagnosis and treatment is most important.

• Archives of Craniofacial Surgery
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• v.10 no.2
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• pp.86-90
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• 2009

Purpose: Inferior blow-out fracture is the common facial fracture. Unsatisfactory functional and aesthetic outcomes are frequent when it is treated inappropriately. If fractures are extended and reach the posterior end of orbital floor, enophthalmos frequently followed as complication. The purpose of this study was to evaluate reduction technique of extensive inferior blow-out fracture with ballooning of foley catheter through endoscopic transnasal approach and implantation of $Medpor^{(R)}$ through subciliary approach. Methods: A retrospective study was performed on 14 patients with extensive inferior blow-out fracture who underwent ballooning of foley catheter through endoscopic transnasal approach with implantation of $Medpor^{(R)}$ through subciliary approach. Patients were operated from May 2005 to November 2007. Data for 14 patients were acquired from patient's charts. Preoperative and postoperative data for enophthalmos, diplopia, limitation of extraocular motion were reviewed. Preoperative and postoperative CT scan were also checked. The patients were followed up from 4 to 18 months. Results: The enophthalmos was corrected in all patients. Among 7 patients with diplopia preoperatively, diplopia was resolved in three patients postoperatively. The diplopia persisted in four patients and two of them also had limitation of extraocular motion postoperatively. The limitation of extraocular motion occurred in seven patients preoperatively. But five patients recovered after operation immediately. These symptoms were resolved about three months after the operation. Conclusion: The ballooning of foley catheter through endoscopic transnasal approach with implantation of $Medpor^{(R)}$ through subciliary approach can be considered one of the appropriate technique for extensive inferior blowout fracture.

• Archives of Craniofacial Surgery
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• v.9 no.2
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• pp.101-104
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• 2008

Purpose: Diplopia and cosmetically unacceptable enophthalmos are the major complications of blow out fracture. Prolapse of orbital tissue into the sinuses, enlarged orbital volume, atrophy of orbital fat and loss of support of orbital walls play a role in the pathogenesis of enophthalmos. To correct post-traumatic enophthalmos, freeing of incarcerated orbital contents combined with reduction of bony orbital volume and reconstruction of suspensory support of globe is necessary. But remained enophthalmos after surgical treatment is difficult to correct completely. In this case, the authors performed implant insertion for affected orbit and endoscopic orbital decompression for unaffected orbit for correction of late enophthalmos. Method: We reviewed a girl patient with right inferomedial orbital wall blow out fracture, right zygoma fracture treated at our hospital for correction of enophthalmos. An 18-year-old female had sustained posttraumatic enopthalmos. Two surgical management was performed for correction blow out fracture at the other hospital. But residual diplopia, enophthalmos, cheek drooping were found. And then she transferred to our hospital. She had severe enophthalmos(5 mm) also had diplopia and extraocular muscle limitation. We performed operation for correction of enophthalmos. After operation, she showed minimal improvement of diplopia and enophthalmos(3 mm). The authors make plan for operation for correction enophthalmos due to cosmetical improvement. Implant insertion was performed for affected orbit. For unaffected orbit, nasoendoscopic medial orbital wall decompression was proceeded. Result: Correction of enophthalmos was found after operation and was maintained for nine years follow-up. Patient expressed satisfaction for the result. Conclusion: To correct persistant enophthalmos, we could have satisfactory result with orbital wall reconstruction on affected eye and decompression on unaffected eye.

• Archives of Plastic Surgery
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• v.38 no.1
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• pp.43-47
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• 2011

Purpose: Sensory impairment in infraorbital nerve is common symptom following mid-facial fractures. The purpose of this study is to document the incidence of sensory impairment in infraorbital nerve following midfacial fractures and its recovery. Methods: Three hundreds fourteen patients with midfacial fracture were included involving emergence areas of infraorbital nerve. Fractures were classified into zygoma fracture, maxilla fracture, complex comminuted fracture and pure blow out fracture. Neurosensory function was assessed with clinical symptoms and light touch test in infraorbital nerve regions. Patients were followed and sensory function was evaluated immediately, 1, 3 and 6 months after trauma. Results: The total series consisted of 198 zygoma fractures, 19 maxilla fractures, 30 complex comminuted fractures and 67 pure blow out fractures. The incidence of sensory impairment was 60% (63% in zygoma fractures, 84% in maxilla fractures, 93% in complex comminuted fractures, 31% in pure blow out fractures). Persistent sensory impairments were remained in 32% (33% in zygoma fractures, 47% in maxilla fractures, 73% in complex comminuted fractures, 6% in pure blow out fractures) 6 months after trauma. Younger patients had better prognosis than older patients in recovery of infraorbital nerve function ($p$ <0.05, $x^2$-test). Mean recovery time was 11 weeks. Conclusion: The incidence of post-traumatic sensory impairment was different according to fracture types. Age of patients and fracture type were important factors that influence to recovery of sensory impairment. Complex comminuted fracture had poor prognosis, and pure blow out fractures had better prognosis than other fractures.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.3
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• pp.312-316
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• 1999

When the external force was applied to the orbit the most thin area might be displaced. These were usually orbital floor and/or medial wall of orbit. Among these cases some who showed the entrapment of the muscle between the fractured fragments needed the surgical treatment. We had operated 4 cases of the "blow-out" fracture via subciliary approach. The entrapped muscles were freed from fragments and the bony defect was restored with micro-titanium mesh. Mean follow-up periods was 15 months and there were no complication observed.

• 대한공업교육학회지
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• v.34 no.2
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• pp.321-330
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• 2009

This study presents the blow molding of injection stretch-blow molding process for PET bottle. The numerical analysis of the blow molding of PET bottle is considered in this paper using CAE with a view to minimize the thickness difference. In order to determine the design parameters and processing conditions in blow molding, it is very important to establish the numerical model with physical phenomenon. In this study, a shell model with thickness has been introduced for the purpose and blow simulations with 3-type blow process condition are carried out. The simulations resulted in the thickness distribution in good agreement with the physical phenomenon. Also, from the result of numerical analysis, we appropriately predicted the thickness distribution along the PET bottle wall and Using the result of numerical analysis we apply the preform design and blow molding process condition for optimization.

• Archives of Craniofacial Surgery
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• v.11 no.2
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• pp.85-90
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• 2010

Purpose: The goals of a blow-out fracture reconstruction are to restore the osseous continuity, provide support for the orbital contents and prevent functional and anatomic defects. Over the past several years, a range of autogenous and synthetic implants have been used extensively in orbital reconstructions. None of these implants have any absolute indications or contraindications in certain clinical settings. However, in extensive blow-out fractures, it is difficult to restore support of the orbital contents, which can cause more complications, such as enophthalmos. This study examined the clinical outcomes of extensive or comminuted blow-out fractures that were reconstructed by the simultaneous use of a titanium mesh plate and $Medpor^{(R)}$. Methods: Eighty six patients with extensive orbital fractures, who were admitted between March 1999 and February 2007, were reviewed retrospectively. The patients' chart and CT were inspected for review. Twenty three patients were operated on with both a titanium mesh plate (Matrix MIDFACE pre-formed orbital plate, Synthes, USA) and $Medpor^{(R)}$ (Porex, GA, USA). The patients underwent pre-operative CT scans to evaluate the fracture site and measure the area of the fracture. A transconjunctival approach was used, and titanium mesh plates were inserted subperiosteally with screw fixation. $Medpor^{(R)}$ was inserted above the titanium mesh plate. The patients were evaluated post-operatively for enophthalmos, diplopia, sensory disturbances and eyeball movement for a period of at least 6 months. Results: No implant-related complications were encountered during the follow-up period. Enophthalmos occurred in 1 patient, 1 patient had permanent sensory disturbance, and 3 patients complained of ocular pain and fatigue, which recovered without treatment. Although there were no significance differences between groups, the use of 2 implants had fewer complications. Therefore, it can be an alternative method for treating blow out fractures. Conclusion: The use of both a titanium mesh plate and $Medpor^{(R)}$ simultaneously may be a safe and acceptable technique in the reconstruction of extensive blow-out fractures.