• Archives of Plastic Surgery
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• v.34 no.5
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• pp.593-598
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• 2007

Purpose: Talipes equinus deformity is defined as impossibility of heel weight-bearing and lacking of improvement of toe-tip gait despite sufficient duration of conservative treatment. The incidence of equinus deformity induces post-traumatic extensive soft tissue defect and subsequently increases it. Severe equinus deformities of the foot associated with extensive scarring of the leg and ankle were corrected using achilles Z-lengthening and free-tissue transfer. Methods: Free radial forearm flap was done in nine cases of eight patients from January 2000 to November 2006. Causes of deformity were post-traumatic contracture (one patient) and post-burn scar contracture (seven patients). Seven patients were male, one patient was female. Mean age was 32.1 (range, 10-57). Flap donors were covered with artificial dermis ($Terudermis^{(R)}$) and split thickness skin graft (five cases), and medium thickness skin graft only (four cases). Results: The size of flaps varied from $6{\times}12$ to $15{\times}12cm$ (average, $12{\times}7.8cm$). Achilles tendon was lengthened 4.2cm on average. Free radial forearm flap was satisfactory in all cases. All patients could ambulate normally after the surgery. Cases having donor coverage with $Terudermis^{(R)}$ were aesthetically better than those having skin grafts only. Conclusion: This study suggested that severe equinus deformities associated with extensive scarring of the leg and ankle can be corrected effectively free radial forearm flap and Achilles tendon lengthening.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.3
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• pp.242-246
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• 2006

Objective : This is to report the criteria of success of intraoral distraction osteogenesis for alveolar augmentation in the severely atrophied alveolar defects through clinical result of 2 cases. Subjects and Methods : Anterior segmental osteotomy was performed and alveolar distractors (Martin and Leibinger, Germany) were applied each in 2 patients with severely defected anterior maxillary area. The osteomized alveolar segments were distracted by 1mm a day after latency period. After the consolidation period implants were installed with removal of distractor. The implants were evaluated clinically and radiographically. Results : In Case I, the distracted bone was directed to the palatal side, and another augmentation treatment - block bone graft, guided bone regeneration - was needed. In Case II, the successful alveolar bone augmentation was achieved. Dental implant was placed on distracted alveolar bone, and showed good osseointegration and good function without any complication. Conclusion : Distraction osteogenesis can be a good choice for alveolar ridge augmentation of severely atrophied ridges. However, the anterior esthetic prosthetics relies on the control of the vector, the kind of distractor, the healing capacity of patient and the etiology of atrophy. Therefore another study of each category would be needed.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.4
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• pp.324-333
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• 2005

Distraction osteogenesis for the advancement of hypoplastic maxilla of cleft patients has shown successful results. In this report, rigid external distraction(RED) system and internal distraction device were used for maxillary advancement. Each system has its advantages and disadvantages. Larger amount of advancement can be achieved with RED system. But complex external device may give patients psychological stress. Internal device is invisible. However its distraction amount have limitation for the advancement (< 20mm) and the vector cannot be changed freely during distraction. The authors treated five cleft patients with maxillary hypoplasia(three with RED system and two with internal distractor). Their results were clinically satisfactory. We present the pros and cons of RED and internal system for maxillary distraction osteogenesis.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.2
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• pp.120-127
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• 2011

Purpose: This study was designed to examine whether the use of neuromuscular electrical stimulation (NMES) after mandibular distraction osteogenesis accelerated bone formation and consolidation. Methods: Eight adult dogs underwent mandibular left body osteotomy. After a 3 day latency period, a distraction rod device was activated at a rate of 1.0 mm once per day for 10 days. After the completion of mandibular lengthening, NMES group was treated twice daily with 2 hours of NMES for 14, and 28 days, while non-NMES group did not receive NMES. The distracted segment was evaluated radiolgraphically histologically and than immunohistochemically for osteopontin (OPN) to evaluate new bone formation and consolidation. Results: Radiography, did not demonstrate significantly different images between the group and the NMES group. Histological examination however, showed that the new bone formation 14 and 28 days after distraction was better in the NMES group when compared to non-NMES group. Immunohistochemical analysis demonstrated that the staining intensity of OPN increased more in the NMES group than in non-NMES group during early consolidation. Conclusion: The results of this study demonstrated that the use of NMES can promote bone formation and consolidation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.6
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• pp.549-558
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• 2006

During distraction osteogenesis, the angiogenic activity is crucial factor in the new bone formation. The aim of this study was to detect the autocrine growth activity in the cellular components of the distracted periosteum with observation of the expression of vascular endothelial growth factor (VEGF) and its receptors following the mandibular distraction osteogenesis. Unilateral mandibular distraction (0.5 mm twice per day for 10 days) was performed in six mongrel dogs. Two animals were sacrificed at 7, 14, and 28 days after completion of distraction, respectively. The distracted lingual periosteum was harvested and processed for immunohistochemical examinations. After then, we observed the expression of VEGF, Flt-1 (VEGFR-1), and Flk-1 (VEGFR-2) in the osteoblasts and immature mesenchymal cells of the distracted periosteum. At 7 days after distraction, the expression of VEGF and its receptors were significantly increased in the cellular components of the distracted periosteum. Up to 14 days following distraction, the increased expressions were maintained in the osteoblastic cells. At 28 days after distraction, the expression of VEGF and its receptors decreased, but VEGF was still expressed weak or moderate in the osteoblastic cells of distracted periosteum. The expression pattern of VEGF and its receptors shown here suggested that VEGF play an important role in the osteogenesis, and these osteoblastic cell-derived VEGF might act as autocrine growth factor during distraction osteogenesis. In the other word, the cellular components in the distracted periosteum, such as osteoblasts and immature mesenchymal cells, might have autocrine growth activity during distraction osteogenesis.

• Elastomers and Composites
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• v.34 no.3
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• pp.229-238
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• 1999

In this study, double bond, unsaturated group was introduced to the main chain of EVA by chemically treating EVA, nondiene polymer. Benzene sulfonic acid, ENB and DCPD were used as a third element. Also, from blending CR and SBR, conventional synthetic rubber we prepared vulcanizates and examined their physical properties. The datum lead to the following conclusion that some problems were modified; limited temperature in use and mechanical properties like hardness, tensile strength, tensile stress, and elongation rate of thermoplastic EVA, keeping the following advantages of original EVA; green strength, injection molding by Pressure, adhesion, tackiness, dimensional stability, and ozone resistance, etc. It is expected that continuous research of the modification between nondiene and diene polymer will improve what were shown disadvantages in synthetic polymer; processing, oxidation resistance, and adhesion. In addition, it will be possible to continue process of rubber products by utilizing possible fluidity for fusion of EVA.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.17.2-17.2
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• 2011

모든 생물은 늙어가면서 그 생물체를 이루고 있는 생체조직들이 낡게 되고 약해지기 마련이며, 이외에도 자동차 사고 등 재해에 의해 생체 장기의 손상을 가져올 수도 있다. 또한 인간의 평균수명 연장과 함께 소득 수준이 높아지고 또한 'quality of life'를 추구하는 고령화 시대로 접어듦에 따라, 인공골, 인공치아 또는 인공 고/슬관절 등의 골조직 대체재료의 수요가 빠르게 증가하고 있다. 이와 같은 골조직 대체, 즉 골이식은 크게 자기골 이식(autografting), 동종이식(allografing), 인공재료(man-made materials)의 이식으로 구분된다. 현재 대체물질의 약 58%를 차지하고 있는 자기골 이식의 경우, 거부면역 반응이 없어 임상성공율이 80%에 달한다는 장점을 가지고 있으나, 비용이 비싸고 감염과 통증의 위험이 있다. 또한 시신으로부터 골을 이식하는 동종이식의 경우 대체물질의 약 34%를 차지하고 있는데, 성공률이 떨어지고 질병 감염의 위험이 있는 단점이 있다. 이외에 약 8%를 차지하고 있는 인공재료 이식의 경우, 파단, 독성반응, 마모, 골조직의 remodeling 등이 일어나는 단점이 있으나, 앞에서 언급한 바와 같이 그 필요성이 급격히 증가함에 따라 보다 나은 치료법과 골이식 대체물질의 개발에 많은 노력이 경주되고 있다. 2003년 6월 미국 Financial Times에 의하면, 인체내 식립형 생체재료의 세계시장 규모는 약 650억 달러에 이르며, 매년 200% 이상씩 신장하고 있다고 한다. 따라서 세계 각국의 의학, 약학, 임상학, 생명과학, 공학 등의 관련 연구 분야에서는 이 수요를 충족시키기 위한 활발한 연구활동을 펼치고 있다. 한편 인체내 식립용 임플란트의 국내 시장규모는 치과 임플란트의 경우 2006년 현재 2000억원 규모로, 정형외과, 악안면 성형외과, 이비인후과를 포함하면 소위 'bone-anchored metal implant' 영역의 시장 규모는 4~5조원에 이를 것으로 추산 되고 있다. 또한 소비 신장률 10~15%를 감안하면 향후 시장 규모는 폭발적으로 증가될 것으로 예상된다. 이에 발맞추어, 최근 들어 선진국은 물론, 국내에서도 인체내 식립을 목적으로 하는 생체재료에 관한 연구개발이 활발히 진행되고 있으며, 일부는 실용화 단계에 진입하고 있다. 본 강연에서는 금속 임플란트의 시장현황과 앞으로의 추세에 대하여 조망하고, Ti 임플란트를 중심으로 이의 생체활성을 부여하는 표면개질 필요성 및 최근의 연구개발 동행에 대해 소개하고자 한다.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.13 no.2
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• pp.185-190
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• 1991

Thr rickets or osteomalacia, that was induced by nonendocrine osseous or soft tissue tumor, is extremely rare disease and fourteen patients has been reported since 1947. The real nature of this disease is unknown, but postulated that unknown phosphaturic subtance which was elaborated from the tumor affect the renal tubule and produce hypophosphatemia and failure of calcification of osseous tissue. This case presented is that of 41-year-old man who suffered from severe generalized aching pain, severe muscular dystrophy, and shortening of the stature 4 years prior hospitalization. The causal coexisting tumor is walnut sized peripheral giant cell granuloma on the upper gingiva. After surgical removal of the tumor, patient's biochemical findings of the serum and urine were returned to the normal limits 12 days later, and clinical symptoms were marked relieved at 6 weeks later. The dental radiograms which were obtained 4 months later revealed remarkable bone regeneration and newly formed alveolar lamina dura.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.2
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• pp.254-261
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• 2000

Since callus distraction technique was applied clinically for the correction of dentofacial deformity to the patients with hemifacial dysplasia by McCarthy in 1992, many surgeons have tried to apply this method to the maxillofacial region. But this technique has some drawbacks. One of the disadvantages of this technique is extensive scar formation in the facial area, which is a sequelae of extraoral approach for supraperiosteal dissection of the periosteum overlying the mandible. Recently, we have made an effort to perform this technique through intraoral approaches to prevent scar formation on the submandibular area and modified the design of the osteotomy, that is step osteotomy technique, to increase the raw bone surface on both osteotomized segments. The rationale for the application of this step osteotomy technique is to increase the amount of regenerated bone and the length of distraction, to avoid damage of inferior alveolar neurovascular bundle, and to increase initial stability of the splitted segments. Step osteotomy procedure can be done with fine micro-osteotomy saw through subperiosteal tunneling. Extraoral pins should be inserted before making the osteotomy. Since 1994 we have applied this technique at 8 sites In 5 patients with mandibular deficiencies: 2 cases of hemifacial microsomia, 1 case of developmental facial asymmetry and 2 cases of mandibular bony defect. Mandibular elongation have been achieved from 12 to 20mm in length. 1 out of 8 site, we experienced non-union in the case of mandibular body defect. Some skeletal relapse and growth retardation phenomenon have been observed in some cases with the longest follow-up of 48 months.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.5
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• pp.415-423
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• 2005

Distraction osteogenesis (DO) is frequently used technique in reconstruction of bony defects resulted from tumor resection, congenital deformity, and trauma in the maxillofacial region. Although the histologic and ultrastructural changes associated with distraction osteogenesis have been extensively described, the exact changing of the surrounding tissues, such as nerve tissues, were still unclear. This study observed the histological changes and the expression of nerve growth factor (NGF) in the inferior alveolar nerve (IAN) after distraction osteogenesis. Unilateral mandibular distraction (0.5 mm twice per day for 10 days) was performed in eight mongrel dogs. Two animals were sacrificed at 7, 14, 28 and 56 days after completion of distraction, respectively. The distracted IAN and contralateral control nerve were harvested and processed for histological and innunohistochemical examinations. The signs of acute nerve injuries, such as demyelination and partial discontinuation of nerver fiber, were observed in the distracted IAN on 7 and 14 days after distraction. The initial remyelination and regeneration of distracted IAN were showed at 14 days after completion of distraction. At 56 days later, the histologic features of distracted IAN was similar to those of the normal control IAN. The expression of NGF was significantly increased in most distracted nerve tissues on 7, 14 and 28 days after distraction. On 56 days after distraction, the expression of NGF returned to the normal level. This study suggested that the acute IAN injury caused by mandibular distraction were mostly recovered during consolidation period. The NGF was seemed to be induced from Schwann cell and damaged nerve tissues, and it may have important roles in the initial healing of damaged nerves.