• Journal of Practical Engineering Education
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• v.8 no.2
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• pp.121-128
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• 2016

In injection molding process, the appearance quality issue occurs in most injection molded article. One of thermal designs for the mold was performed by increasing the cavity wall temperature with being as uniform as possible in any position. On the basis of the practical evaluation, the cavity wall temperature and finishing machined cavity surface under the optimum processing conditions are the most significant factors to avoid the appearance issue on the plastic part for a good cosmetic quality. Also, the wrong choice of gate type and location can have a considerable effect on the quality of a molded part and it's so important to keep the correct runner balance from each cavity. We've proposed the education training model of the practical tool technology course for the field oriented education to improve practical tool technology ability and optimized tooling design for injection molding quality which can be performed at the workplace substantially.

• Restorative Dentistry and Endodontics
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• v.42 no.3
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• pp.168-175
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• 2017

Objectives: This double-blind randomized placebo-controlled clinical trial evaluated the ability of a desensitizing agent and a self-etch adhesive on cervical dentin sensitivity (CDS) after periodontal surgery. Materials and Methods: Ninety hypersensitive teeth of 13 subjects were included in the study. After periodontal surgery, the teeth of each posterior sextant treated with one of the following materials: G1: Clearfil $S^3$ Bond (Kuraray Dental), G2: Gluma Desensitizer (Heraeus Kulzer), and G3: placebo (water). The sensitivity was assessed using evaporative stimuli before treatment (baseline, T0), 1 day after treatment (T1), after 1 week (T2), and 1 month (T3) according to visual analog scale (VAS). Results: Following the treatment, all the 3 groups showed significant reduction of CDS in T1 compared to T0. Reduction of CDS between T1 and T2 was observed only in G1 but there was no significant difference between T2 and T3 in this group. Although we observed a significant difference in T3 compared to T1 and T2 in G2 and G3, comparison of treatment groups in each assessment time showed a significant difference only in T3. According to paired comparison, this was due to the difference between G2 and G3. Conclusions: Dentin sensitivity following periodontal surgery will decrease spontaneously over time, but treating the sensitive teeth with Gluma Desensitizer and Clearfil $S^3$ Bond can have some benefits.

• Archives of Plastic Surgery
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• v.32 no.5
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• pp.555-560
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• 2005

The nose is shaped as a pyramid and is the most prominent portion of the face. Nasal bone fractures are thus more frequent than those of the maxilla and zygoma. Whether the nasal bone fractures are corrected or not due to unnecessity of surgical treatment, the incidence of posttraumatic deformity occurs frequently. In Asian patients, even the corrected noses look low-lying and flat. To resolve these problems, we corrected the posttraumatic deformity of the nose with a combined procedure of nasal ostectomy and augmentation rhinoplasty. From 2000 to 2004, this procedure was performed in fifteen patients with posttraumatic nasal deformity. There were four female and eleven male patients with an average age of 32 years(range 19 to 52 years). All patients had previous trauma history. Of these, closed reduction was performed on 13 patients and no treatment was 2 patients. The deformed noses were corrected through lower columellar incision, by ostectomy or osteomy, and augmentation with silicone implant. We gained satisfactory results of correcting the deformed noses, except one case with implant deviation. Our method for the correction of traumatic nasal deformity proves to be simple and safe. The camouflage effect with silicone implant overcomes an unsatisfactory correction and brings a excellent cosmetic results.

• Archives of Plastic Surgery
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• v.34 no.1
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• pp.137-139
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• 2007

Purpose: The mandibular ramus sagittal split osteotomy is a common procedure in cosmetic surgery. A late complication of this procedure, pseudoaneurysm rarely happens. The purpose of this case is to present our experience that is rare late vascular complication after mandibular ramus sagittal split osteotomy. Methods: A 21-year-old male was operated by local plastic surgeon for treatment of mandibular prognathism. After 9 days, the man was transferred to our hospital with persistent bleeding and swelling on the mandibular area. We operated the man three times and failed to control hemorrhage. Therefore, we did angiography and found the pseudoaneurysm on the buccal and pterygoid branches of internal maxillary artery. Then we did selective embolization for removal of the pseudoaneurysm. Results: The man was operated using the therapeutic embolization, and the pseudoaneurysm was removed. The results were successful, and we couldn't find any bleeding and the pseudoaneurysm during the follow-up of 12 months. Conclusion: The selective embolization is the good therapeutic method of late vascular complication after mandibular ramus sagittal split osteotomy.

• Archives of Plastic Surgery
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• v.34 no.1
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• pp.64-69
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• 2007

Purpose: The key of treatment in syndactyly is to separate the fused digits safely, and to create a normal web space with enough cutaneous coverage. Despite many techniques have described the correction of syndactyly, skin graft still remains the annoying one. We designed the pentagonal flap from hand dorsum to reconstruct the web space reliably and try to minimize the need for skin graft. Methods: Between July 2003 and August 2005, six cases of syndactyly were corrected at UCLA Medical Center and Hallym University Sacred Heart Hospital using dorsal pentagonal flap for web space reconstruction and straight incisions for the sides of digits to minimize the need for skin graft. The proximal edge of the pentagonal flap was designed in V shape to allow for easy closure of the donor site after advancement. The pentagonal flap was advanced volarly with the underlying dermofat tissues to form a digital web. In some cases, skin defects were unavoidable and covered with full thickness skin graft from the inguinal area. Results: Syndactyly were seen in 4 cases of Apert syndrome, 1 postburn scar webbing with PIP joint contracture and 1 recurrence after the incomplete reconstruction. In all Apert syndrome, straight line incision was used along the sides of the fingers and skin graft was needed. But, in 2 cases of incomplete type, we could save the need for skin graft only for the correction of syndactyly. We could get a good looking web space without any complications such as flap or graft loss. Conclusion: As a modification of Sherif's V-Y dorsal metacarpal flap, we believe pentagonal flap could be one of the easiest and safest way to reconstruct the web space of syndactyly in functional and cosmetic standpoint.

• Archives of Plastic Surgery
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• v.34 no.4
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• pp.461-465
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• 2007

Purpose: Nasal bone fracture may be the most common fracture among facial trauma. However, diagnosis and treatment tend to be overlooked while the reduction and maintenance of fragments remain complicated. Thus, the results are plagued with high rate of nasal deformity which leads cosmetic and functional discomfort. We took advantage of the fact that the nasal bone is one of the thinnest facial bone while at the same time being located close to the skin and utilized ultrasound in performing reduction of nasal bone. Methods:This method was performed on 25 patients with nasal bone fracture. The CL 15-7 linear array transducer (10-15MHz) ultrasound which provides a total of 7 views (3 axial views and 4 transverse views) of the elevator under the bony fragments was enough for the surgeon to accurately perform the reduction. Results: In our class, an accurate and precise reduction has been made possible by real time images before, during, and after the procedure with the help of ultrasound while reducing the exposure to radiation. Conclusion: Compared to previous methods, satisfaction of patients has increased in the nasal tip, minimal fracture of the side wall and secondary reduction cases. Therefore, the incorporation of ultrasound in the closed reduction of nasal bone may prove to be a useful method.

• Archives of Plastic Surgery
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• v.34 no.2
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• pp.222-228
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• 2007

Purpose: Report of the good results of breast reconstruction using Becker permanent tissue expander that showed a short operation time and a quick post-operation recovery time, little side effects and usually superb aesthetic results without the need for additional incisions or donor site morbidity. The authors, after carrying out breast reconstruction operations using Becker permanent tissue expander on patients with appropriate indications, attempted to analyze several factors such as complication rates and patient satisfaction measurements. Methods: 11 cases of breast reconstruction using Becker expander implants were carried out on a total of 10 patients between March 2000 and February 2003. The patients were followed up at outpatient visit for an average of 6 months. Results: The most common post-operation complication was pain resulting from saline injection into the expanders, complained by 5 patients(50%). rib fractures, skin necrosis, implant removal due to infection, and breast cancer recurrence each occurred in 1 patient (9.9%). There was no occurrence of skin contracture complications which occurs frequently in case of silicone implant insertion. Patient complacency was surveyed by patient interviews made right after the operations and during outpatient follow-up periods: 5(50%) patients out of 10 showed excellent, 3(30%) good, and 2(20%) showed fair, leaving no patients who were disappointed with operation results. On routine follow-up, 80% of patients expressed satisfaction with the cosmetic outcome of their post-mastectomy beast reconstruction. Conclusion: Breast reconstruction using the Becker expander is a reliable alternative to other reconstructive methods but good patient selection is essential for satisfactory results.

• Archives of Plastic Surgery
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• v.37 no.6
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• pp.788-794
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• 2010

Purpose: The fingertip is the most commonly injured part of the hand and its injury frequently results in avulsion or crushing of a segment of the nail bed and fracture of the distal phalangeal bone. Restoration of a flat and smooth nail bed is essential for regrowth of a normal nail, which is important not only for cosmetic reasons but also for tactile capability of the fingertip. It is also anatomical reduction of the distal phalanx to promote patient's cosmetics and prevent nail bed deformity. Absence or no replacement of the nail plate results in obliterated proximal skin fold. When the avulsed nail plate cannot be returned to its anatomic position or when it is absent, we use a synthetic material for splinting the nail bed and alternative reductional method for distal phalangeal bone fracture, especially, instead of hardwares. Methods: From January of 2006 to June of 2009, a total of ten patients and fourteen fingers with crushing or avulsion injuries of the fingertip underwent using the artificial nails for finger splint. We shaped artificial nails into the appropriate sizes for use as fingernail plates. We placed them under the proximal skin fold and sutured to the fold proximally and to the lateral and medial edges of the nail bed or to the distal fingertip. Our splints were as hard as K-wire and other fixation methods and more similar to anatomic nail plates. Artificial nails were kept in place for at least 3 weeks. Results: No artificial nail related complication was noted in any of the ten cases. No other nail fold or nail bed complications were observed, except for minor distal nail deformity because of trauma. Conclusion: In conclusion, in order to secure the nail bed after injury and reduce the distal phalangeal bone fracture, preparing a nail bed splint from a artificial commercial nail is a cheap and effective method, especially, for crushed or avulsion injuries of the fingertip.

• Archives of Plastic Surgery
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• v.37 no.6
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• pp.749-757
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• 2010

Purpose: Since skin sparing mastectomy removes the mammary gland and the nipple-areolar complex preserving all mammary skin, it makes the widespread use of implants in immediate reconstruction. This article reports our experience in immediate breast reconstruction after skin sparing mastectomy by using the silicone implants in patients especially who have small to moderate sized and minimal ptotic breast. Methods: From September of 2007 to July of 2009, we performed breast reconstruction for 44 breasts of 40 women with silicone implant after mastectomy. Tumors were divided into 5 malignant types (21 IDC, 18 DCIS, 2 ILC, 2 phylloides tumor, 1 mucinous carcinoma). The implant is placed in a submuscular pocket or in a submuscularsubfascial pocket depending upon the condition of the muscles and skin flaps after mastectomy. Results: The mean age was 47 years and the average follow-up period was 11 months. Cosmetic outcome was assessed by evaluation of photographs and assessment of breast volume and shape, breast symmetry, and overall outcome. About 80% of each of these parameters was scored as good or excellent. Breast complication was developed in a total of 6 cases including 2 capsular contracture, 2 partial skin necrosis due to blue dye injection and 2 implant infection. Conclusion: The use of definitive implants in a skin sparing mastectomy is a one-stage immediate breast reconstruction with low morbidity and acceptable result. This method is considered reliable with favorable aesthetic result.

• Journal of Chest Surgery
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• v.31 no.9
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• pp.915-918
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• 1998

The chest wall deformity associated with Poland's syndrome is a very rare anomaly which consists of congenital unilateral absence of the sternal head of the pectoralis major muscle and various abnormalities of the upper extremity. Other clinical features associated with Poland's syndrome include deficiency or absence of the breast and nipple, deficiency of subcutaneous fat and axillary hair, and abnormalities of costal cartilages and anterior ends of ribs. The origin remains uncertain, but is considered not to be hereditary. Poland's syndrome may pose a serious psychologic and cosmetic problem, early recognition and surgical correction may prove beneficial. A 37 year old patient with Poland's syndrome was encountered and underwent satisfactory surgical correction.