• Korea Journal of Hospital Management
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• v.23 no.3
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• pp.87-103
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• 2018

Purpose: This study investigates the best appointment pattern which can enhance customer's satisfaction and hospital's efficient management reflecting plastic surgery clinic's service characteristics. Methodology: The data of this study is obtained from Plastic surgery Clinic which is located in the civic center. By collecting and analyzing the data, we build the simulation model using ARENA. Based on 5 appointment patterns that was suggested in formal appointment scheduling studies, we experiment 3 simulation models; 'Basic Appointment Pattern' that has no restriction, 'Restriction on Second Customer' that restricts the number of second customer's in each slot, 'Restriction on Process Time' that restricts the number of second customer who has long process time in each slot. We can check robustness of the appointment patterns by experimenting on off-peak day and peak day, during peak season. Findings: This study confirms that these 2 restrictions can give a better result than 'Basic Appointment Pattern' that just simply distributes customers by number. Especially, the performance of Triangle-like pattern which is the best appointment pattern in the formal study has been improved by adding restrictions. Based on 'DET', 'Restriction on Second Customer' shows a better result. Meanwhile, based on 'E(WT)', 'Restriction on Process Time' shows a better result. Overall, based on 'DET+E(WT)', 'Restriction on Second Customer' shows a better result. Practical Implications: The purpose of each hospital may alter as demand for plastic surgery grows increasingly. Thus, each hospital should be always prepared to introduce appointment pattern for changed purpose. In order to respond flexibly to these changes, it is necessary for medical personnel to improve the awareness or for hospital to create an environment by constructing appointment program so that medical personnel does not need to put more labor on work.

• Archives of Craniofacial Surgery
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• v.19 no.2
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• pp.135-138
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• 2018

Parry-Romberg syndrome is a rare neurocutaneous syndrome characterized by progressive shrinkage and degeneration of the tissues usually on only one side of the face. It is usually difficult to restore the facial contour due to skin tightness. In this case report, we report a forehead reconstruction with custom-made three-dimensional (3D) titanium implant of a Parry-Romberg syndrome patient who was treated with multiple fat grafts but had limited effect. A 36-year-old man presented with hemifacial atrophy. The disease progressed from 5 to 16 years old. The patient had alopecia on frontal scalp and received a surgery using tissue expander. The alopecia lesion was covered by expanded scalp flap done 22 years ago. Also, he was treated with fat grafts on depressed forehead 17 years ago. However, it did not work sufficiently, and there was noted depressed forehead. We planned to make 3D titanium implant to cover the depressed area (from the superior orbital rim to the vertex). During the operation, we confirmed that the custom-made 3D implant accurately fit for the depressed area without any dead spaces. Previously depressed forehead and glabella were elevated, and the forehead contour was improved cosmetically. A custom-made 3D titanium implant is widely used for skull reconstruction and bring good results. In our case, the depressed forehead of a Parry-Romberg syndrome patient was improved by a 3D titanium implant.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.6 no.3
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• pp.21-30
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• 1986

A method for elasto-plastic analysis of grillages is proposed in this investigation. An effort to construct the stiffness matrix of the member with bending and torsional springs attached at both ends is made in this work to make each member of grillage behave elasto-plastically. A related computer program EPAG for elasto-plastic analysis of grillages is also developed. The characters of this program in comparison with existing methods are as fellows; grillage with arbitrary geometry can be analysed, collapse load is applied in one step instead of incremental procedure, unloading can be considered, and analysis results such as applied loads, member end forces and joint displacements are also obtained when individual plastic hinge is formed. For verification of performanse of the EPAG, illustrating examples are solved and compared with the results of specified literlatures.

• Archives of Plastic Surgery
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• v.38 no.1
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• pp.81-84
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• 2011

Purpose: Nerve injury is one of the complication which can develop after brow lift. Peripheral nerve ending which is stretched from supraorbital nerve and supratrochlear nerve can be injured and symptoms such as pain, dysesthesia may appear. Usually, developed pain disappeared spontaneously and does not go on chronic way. We experienced a case that a patient complained chronic pain after brow lift which was not controlled by conservative management such as medications, local nerve block and report a successful surgical treatment of chronic pain after brow lift. Methods: A 24-year-old male who received brow lift with hairline incision at local hospital was admitted for chronic pain at the right forehead. The pain was continued for 3 months even though fixed thread was removed. Local nerve block at trigger point with mixed 1 mL 2% lidocaine and 1 mL Triamcinolone acetonide was done and oral medications, Gabapentine and carbamazepine, were also applied but there was no difference in the degree of pain. Therefore the operation was performed so that careful dissection was carried out at right supraorbital neurovascular bundle and adhered supraorbital nerve was released from surrounding tissues and covered with silastic sheet to prevent adhesion. Results: The pain was gradually relieved for a week. The patient was discharged without complications. No evidence of recurrence has been observed for 2 years. Conclusion: The pain developed after brow lift was engaged with nerve injury and sometimes remains chronically. Many kinds of conservative management to treat this complication such as medications, local nerve block have been reported and usually been used. But there are some chronic cases that conservative treatment do not work. In sum, we report 1 case of successful surgical treatment for relief of intractable pain developed after brow lift surgery.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.1
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• pp.71-81
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• 2009

Die steel for plastic molding were used as mold material of automobile parts and electronic component industry. The material of this paper has superior to mechanical properties, such as repair weldability, corrosion resistance and high temperature strength, required mold parts for semitransparent. Laser-induced surface hardening technology is widely adopted to improver fatigue life and wear resistance via localized hardening at the surface of mold parts. The objective of this research work is to investigate on the characteristics of surface hardening of the laser process parameters, such as beam travel speed, laser power and defocsued spot position, for the case of die steel for plastic molding. Lens for surface hardening of large area is plano-convex type with elliptical profile to maintain uniform laser irradiation. According to the experimental results, large size of hardened layer at the surface of die steel for plastic molding was achieved, and microstructure of this layer was lath martensite. Optimal surface status and mechanical property of hardened layer could be obtained at 1095Watt, $0.25{\sim}0.3m/min$, 0mm (focal length: 232mm) for laser power, beam travel speed, and focal position. Where, heat input was $0.793{\times}10^{3}J/cm^2$, and width of hardened layer was 27.58mm.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.1
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• pp.65-69
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• 2008

This work shows that the grinding-induced scratches formed on the back surface of silicon chips can highly influence the flexural strength of the chips. Meanwhile, in a case that excellent adhesion between the back surface and the plastic package body maintains, the flexural strength of plastic-encapsulated packages is not so sensitive to the geometry of the scratch marks. This article explains why such different flexural fracture behavior between bare chips and plastic-encapsulated chips appears.

• Archives of Plastic Surgery
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• v.36 no.4
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• pp.485-488
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• 2009

Purpose: Malignant melanoma of the lower extremity is well known to metastasize to the lymph nodes of the groin. However, in rare cases, the initial site of the nodal disease can be the popliteal fossa. As of yet, there has not been any report on cases with popliteal lymph node metastasis in Koreans. In the following report, authors would like to present two cases of popliteal node metastasis. Methods: A 60 - year - old male patient presented with nodular mass at his left sole. He had popliteal node metastasis detected on preoperative positron emission tomography(PET). Another 67 - year - old man presented with pigmented lesion at his right heel. He also had popliteal node metastasis detected on the MRI. They underwent wide excision of the primary lesion with popliteal node dissection. Results: In the first case, $2.5{\times}2.5cm$ sized metastatic melanoma in popliteal node was pathologically confirmed. There were no postoperative complications, and to date(18 months after the surgery), the patient is alive with no evidence of disease. In the second case, multiple(4) metastatic melanoma in popliteal nodes was confirmed. The patient is alive, but has had interferon therapy for liver metastasis. Conclusion: By increasing the use of lymphoscintigraphy or PET as a preoperative diagnostic work - up for metastasis, even popliteal node metastasis undetectable in a physical exam becomes detectable. When metastatic lymph node is found, node dissection is the standard of care. Therefore, it is essential that we know the anatomy and surgical technique for popliteal lymph node dissection.

• Archives of Plastic Surgery
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• v.36 no.4
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• pp.507-511
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• 2009

Purpose: Adenoid cystic carcinoma (ACC) is a rare malignant epithelial neoplasm derived from the salivary glands. In some cases, ACC may arise in other primary sites, such as skin. We report a case of adenoid cystic carcinoma arising the scalp skin of 69 - year - old woman. Methods: A 69 - year - old woman presented with a tender scalp nodule. A local wide excision was performed. Histopathologic examination was revealed the adenoid cystic carcinoma with basaloid cells in a cribriform pattern. The resection margins were free of tumor. Two years later a tumor recurred in the scarred area. The lesion was removed surgically and the histopathological diagnosis of adenoid cystic carcinoma was again established. After two years, tumor recurred again and diatant metastasis of the lung was diagnosed. A surgical wide excision was done and the close regular follow - up for recurrence was done. Two years later, third recurrence of the scalp was observed. We also performed the wide local excision with tumor free margin. Results: We experience the recurrent adenoid cystic carcinoma of the scalp with pulmonary metastasis. We have performed the wide local excision for three times. The patient has been followed up for 10 years with regular work - up for recurrence and metastasis Conclusion: primary cutaneous adenoid cystic carcinoma is a rare skin neoplasm with a high potential for recurrence after local excision. The standard treatment of ACC is wide local excision with tumor - free margins established by permanent section.

• Archives of Plastic Surgery
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• v.35 no.4
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• pp.379-384
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• 2008

Purpose: Currently, using perforator artery flaps especially anterolateral thigh flaps are widely used for reconstruction of extremities, head and neck. Obtaining a precise anatomical picture prior to operation will translate to a more accurate, efficient and safe procedure. Authors used 3D-image work up via 64-slice MDCT to make a more precise preoperative plan. Methods: A total of 10 patients underwent soft tissue reconstruction with anterolateral thigh flap from December 2006 to December 2007. The 64-Channel MDCT (LightSpeed VCT, GE, USA) was used and 3D images were reconstructed. Findings from MDCT were applied to the preoperative planning and confirmed with intraoperative findings. Results: The average number of perforator arteries from lateral circumflex femoral artery was 2. The average lengths of vascular pedicle from the origin of lateral circumflex femoral artery to the first and second perforator artery were 11.0 cm and 20.0 cm, respectively. The average diameter of the pedicle artery was 2.2 mm. The locations of the perforator arteries were mapped and localized on the body surface based on the MDCT result. These were confirmed through direct visualization intraoperatively. Conclusion: MDCT has an advantage of obtaining accurate images of the general anatomy and even fine structures like perforator arteries. By using this state-of-the-art diagnostic imaging technique, it is now possible to make an operative plan safely and easily.

• Archives of Plastic Surgery
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• v.36 no.6
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• pp.803-805
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• 2009

Purpose: Many conditions can mimic the presentation of burns. Herpes zoster is one of them. The characteristic features of herpes zoster such as vesicles, pustular lesions and crusts can also be found in burns. Herpes zoster ophthalmicus is a disease caused by recurrent infection of varicella - zoster virus in the ophthalmic division of the trigeminal nerve. This virus frequently affects nasociliary branch and serious ocular complications can occur. Thus, early diagnosis and proper treatment of this disease is important to prevent further ocular manifestations. We report a man who sustained minor facial burn injury that was complicated with herpes zoster ophthalmicus. Methods: A 66 - year - old man visited emergency room with multiple whitish vesicles with serous discharge on right forehead, right medial canthal area and nose. At first he was thought to have a secondary infection of facial burn injury. The vesicles on his face began to form crusts on the next day. Since his skin lesion was located on the ophthalmic division of trigeminal nerve, we also suspected herpes zoster ophthalmicus. He was referred to dermatologist and ophthalmologist. Results: We used antiviral agent (Acyclovir) and NSAIDs for treatment. The patient had no ocular complications. His skin lesion was almost healed after 1 month and remained scars. We treated a patient with minor facial burn complicated with herpes zoster ophthalmicus with antiviral agent. Conclusion: In this work, we describe a case of old patient with herpetic infection and emphasize the need for careful examination to diagnose accurately.