• 대한두경부종양학회지
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• 제11권1호
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• pp.47-55
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• 1995

A large lateral facial defects especially a through and through defect of the cheek remains as challenging field of reconstruction for the head and neck surgeons. Closure of these wounds is technically troublesome due to the magnitude and location of the soft tissue and skin defect, functional and aesthetic consideration. optimal cancer surveillance, and desire for good nourishment. Most traditional methods dealing with these defects, including split-thickness skin graft, local and regional flaps as well as musculocutaneous flaps have their limitations. We applied four different methods for these reconstruction in four cases. We utilized temporal muscle flap, forearm free flap and secondary healing for repair of mucosal defects, and medial base cervicopectoral flap, pectoralis major myocutaneous flap and cervicofacial flap for the reconstruction of external skin defects. In one case, both sides were reconstructed with single forearm free flap. In our experiences, secondary healing could be one of the useful method for mucosal repair in the defect between upper and lower gingivobuccal sulcus. However, forearm free flap was thought to be more ideal for the cases with mandibulectomy. For the external repair, the regional skin flap was considered to be superior to pectoralis major myocutaneous flap or forearm free flap especially on color matching.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권5호
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• pp.380-390
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• 2004

Bone healing plays an important role in orthognathic and craniofacial surgery. Bone tissue repair and regeneration are regulated by an array of growth and morphogenetic factors. Bone formation and remodeling require continuous generation of osteoprogenitor cells from bone marrow stromal cells, which generate and respond to a variety of growth factors with putative roles in hematopoiesis and mesenchymal differentiation. In this study, the efficacy of a single application of hepatocyte growth factor to promote bone regeneration in 5-mm experimental calvarial defects of adult male rats was assessed histologically and immunohistochemically. The result of the experimental site were compared with those of the contralateral contral side. None of the control and experimental bone defects demonstrated complete bone closure. Bone regeneration was found close th the margine and central part of the defects. At 1, 2 weeks, there were found much significant cellural mitotic activity and many inflammatory cells and osteoblasts on the experimental site than control site. At 4, 6 weeks, new bone apposition was founded in both site but, more apposition was seen at experimental site. At 8, 12 weeks, also, some differences was found that more apposition of new bone and collagen fiber was seen on experimental site. Our results have some possibility that HGF do a early positive role to repair the bone defect. More study will be needed.

• Archives of Plastic Surgery
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• 제47권2호
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• pp.187-193
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• 2020

Upper limb nerve damage is a common condition, and evidence suggests that functional recovery may be limited following peripheral nerve repair in cases of delayed reconstruction or reconstruction of long nerve defects. A 26-year-old man presented with traumatic injury from a wide, blunt wound of the right forearm caused by broken glass, with soft tissue loss, complete transection of the radial and ulnar arteries, and a large median nerve gap. The patient underwent debridement and subsequent surgery with a microsurgical free radial fasciocutaneous flap to provide a direct blood supply to the hand; the cephalic vein within the flap was employed as a venous vascularized chamber to wrap the sural nerve graft and to repair the wide gap (14 cm) in the median nerve. During the postoperative period, the patient followed an intensive rehabilitation program and was monitored for functional performance over 5 years of follow-up. Our assessment demonstrated skin tropism and sufficient muscle power to act against strong resistance (M5) in the muscles previously affected by paralysis, as well as a good localization of stimuli in the median nerve region and an imperfect recovery of two-point discrimination (S3+). We propose a novel and efficient procedure to repair >10-cm peripheral nerve gap injuries related to upper limb trauma.

• 한국임상수의학회지
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• 제33권6호
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• pp.332-339
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• 2016

Polycaprolactone (PCL) scaffold have been developed as an alternative to natural donor tissue to repair a large osteochondral defect. The objective of this study is to evaluate efficacy and biocompatibility of bilayer PCL scaffold implanted for osteochondral repair in rabbit. Twenty-two male New Zealand White rabbits were used in this animal experiment. Rabbits were divided into three groups. Experimental surgery was carried out under general anesthesia. Osteochondral defects (5 mm diameter and 5 mm deep) were made in the center of the patellar groove using a 5 mm diameter biopsy punch. In group I (3D plotting) and group II (salt-leaching), the scaffold was implanted using the press-fitted technique into the defect. In control group, after osteochondral defect was created, the defect was left without implant. After four and eight weeks, rabbits were sacrificed and the defects were evaluated by macro -and microscopical methods. There were not found animal death and severe inflammatory evidence during the experimental periods. There were no significant differences between the experimental groups in gross evaluation. However the group I scored significantly higher than group II at 8 weeks in histological evaluation (P < 0.05). The 3-D plotting PCL scaffold was more suitable method for reconstruction of osteochondral defect than a salt-leaching PCL scaffold.

• Structural Engineering and Mechanics
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• 제86권4호
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• pp.487-501
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• 2023

Nanoparticles have lower size and larger specific surface area, good stability and less toxic and side effects. In recent years, with the development of nanotechnology, its application range has become wider and wider, especially in the field of biomedicine, which has received more and more attention. Bone defect repair materials with high strength, high elasticity and high tissue affinity can be prepared by nanotechnology. The purpose of this paper was to study how to analyze and study the composite materials for sports bone injury based on multifunctional nanomaterials, and described the electrospinning method. In this paper, nano-sized zirconia (ZrO₂) filled micro-sized hydroxyapatite (HAP) composites were prepared according to the mechanical properties of bone substitute materials in the process of human rehabilitation. Through material tensile and compression experiments, the performance parameters of ZrO₂/HAP composites with different mass fraction ratios were analyzed, the influence of filling ZrO₂ particles on the mechanical properties of HAP matrix materials was clarified, and the effect of ZrO₂ mass fraction on the mechanical properties of matrix materials was analyzed. From the analysis of the compressive elastic modulus, when the mass fraction of ZrO₂ was 15%, the compressive elastic modulus of the material was 1222 MPa, and when 45% was 1672 MPa. From the analysis of compression ratio stiffness, when the mass fraction of ZrO₂ was 15%, the compression ratio stiffness was 658.07 MPa·cm³/g, and when it was 45%, the compression ratio stiffness is 943.51MPa·cm³/g. It can be seen that by increasing the mass fraction of ZrO₂, the stiffness of the composite material can be effectively increased, and the ability of the material to resist deformation would be increased. Typically, the more stressed the bone substitute material, the greater the stiffness of the compression ratio. Different mass fractions of ZrO₂/HAP filling materials can be selected to meet the mechanical performance requirements of sports bone injury, and it can also provide a reference for the selection of bone substitute materials for different patients.

• Restorative Dentistry and Endodontics
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• 제46권4호
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• pp.48.1-48.10
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• 2021

Objectives: This study aimed to evaluate the effects on bone repair of different concentrations of mineral trioxide aggregate (MTA) added to AH Plus. Materials and Methods: Bone tissue reactions were evaluated in 30 rats (Rattus norvegicus) after 7 and 30 days. In the AH + MTA10, AH + MTA20, and AH + MTA30 groups, defects in the tibiae were filled with AH Plus with MTA in proportions of 10%, 20% and 30%, respectively; in the MTA-FILL group, MTA Fillapex was used; and in the control group, no sealer was used. The samples were histologically analyzed to assess bone union and maturation. The Kruskal-Wallis and Mann-Whitney tests were performed for multiple pairwise comparisons (p ≤ 0.05). Results: At the 7-day time point, AH + MTA10 was superior to MTA-FILL with respect to bone union, and AH + MTA20 was superior to MTA-FILL with respect to bone maturity (p < 0.05). At the 30-day time point, both the AH + MTA10 and AH + MTA20 experimental sealers were superior not only to MTA-FILL, but also to AH + MTA30 with respect to both parameters (p < 0.05). The results of the AH + MTA10 and AH + MTA20 groups were superior to those of the control group for both parameters and experimental time points (p < 0.05). Conclusions: The results suggest the potential benefit of using a combination of these materials in situations requiring bone repair.

• 대한물리의학회지
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• 제9권2호
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• pp.133-140
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• 2014

PURPOSE: The purpose of this study was to compare the effect of current density on penetration depth, tissue concentration and transdermal transport of methylene blue(MB) by iontophoretic transdermal delivery. METHODS: Twenty-four male Sprague-Dawley rats were randomly divided into 1 mA($0.11mA/cm^2$), 2 mA($0.22mA/cm^2$), 4 mA($0.44mA/cm^2$), and 8 mA($0.89mA/cm^2$) groups. These rats were exposed to anodic iontophoresis of 1% MB using a direct current for 15 minutes. The penetration depth were measured using light microscopy from cryosections of skin tissue. The tissue concentration and transdermal transport were measured using biochemical analysis from target skin tissues. The data were analyzed with one-way analysis of variance. RESULTS: The significant differences in the penetration depth, tissue concentration and transdermal transport were detected among the groups(p<.001). Post hoc comparisons of the penetration depth, tissue concentration and transdermal transport of he 2 mA, 4 mA, and 8 mA iontophoresis groups were greater than in the 1 mA iontophoresis group(p<.05). There was no significant difference, however, among 2 mA, 4 mA, and 8 mA iontophoresis group. CONCLUSION: There was no difference in the efficiency of iontophoresis from 2 mA($0.22mA/cm^2$) to 8 mA($0.89mA/cm^2$). Higher current density can cause skin injury and discomfort sensation. In general, $0.5mA/cm^2$ is proposed to be the maximum iontophoretic current which should be used on human. The appropriate current amplitude should be selected by considering the safety current density and the depth of the target tissue.

• Journal of Periodontal and Implant Science
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• 제32권1호
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• pp.89-112
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• 2002

The earliest reports of the use of electrical energy to directly stimulate bone healing seem to be in 1853 from England, the techniques involved the introduction of direct current into the non-united fracture site percutaneously via metallic needles, with subsequent healing of the defect. One endpoint of the periodontal therapy is to generate structure lost by periodontal diseases. Several procedural advances may support regeneration of attachment, however, regeneration of alveolar bone does not occur consistently. Therefore, factors which stimulate bone repair are areas for research in periodontal reconstructive therapy. Effects of cytokines or growth factors on bone repair are examples of such areas. Another one is electrical current which occurs in bone naturally, so that such bone may be particularly susceptible to electrical therapy. The purposes of this study were to observe the effects of electrical stimulation on the normal periodontium, to determine whether the electricity is the useful means for periodontal regeneration or not. Forty rats weighted about 100 gram were used and divided into 4 groups, the first group, there was no electrical stimulation with the connection of electrodes only. In the second group, there was stimulated by the 10 mA during 10 minutes per a day, in the third group was stimulated by the 25 mA , and the fourth by the 50 mA. At 3, 5, 10 and 15 days post-appliance , two rats in each group were serially sacrificed. and the maxillae and the mandible processed to paraffin, and the specimens were prepared with Hematoxylin-Eosin stain for the light microscopic evaluation. The results of this study were as follows : 1. There was the distinct reversal line on the lingual alveolar crest, whereas a little changes in the labial alveolarcrest to the duration and amount of currents. 2. In 50 mA group, the cells were highly concentrated at the apex of anterior teeth, and was observed the necrotic tissue. In posterior root apex, the hypercementosis was appeared, and newly formed cementum layer has been increased continuously with the time. 3. The periodontal ligament fiber and Sharpey's fiber were arranged in order, and the bone trabeculae were increased as the experiment proceeded by, relatively the bone marrows were decreased. 4. In the pulp tissue, the blood vessels were increased with blood congestion in the experimetal specimens remarkably, and the dentinal tubules were obstructed . 5. The osteoblasts in alveolar bone proper had been showed highly activity, and also observed the formation of bone trabeculea. In the conclusion, it was suggested that the electrical stimulation has influence on the periodontium and the pulp tissue. However, there might be the injurious effects.

• Animal cells and systems
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• 제2권1호
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• pp.1-8
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• 1998

Hepatocyte growth factor (HGF), originally discovered and cloned as a powerful mitogen for hepatocytes, is a four kringle-containing growth factor which specifically binds to membrane-spanning tyrosine kinase, c-Met/HGF receptor. HGF has mitogenic, motogenic (enhancement of cell movement), morphogenic (e.g., induction of branching tubulogenesis), and anti-apoptotic activities for a wide variety of cells. During embryogenesis, HGF supports organogenesis and morphogenesis of various tissues, including liver, kidney, lung, gut, mammary gland, and tooth. In adult tissues HGF elicits an organotrophic function which supports regeneration of organs such as liver, kidney, lung, and vascular tissues. HGF is also a novel member of neurotrophic factor in nervous systems. Together with the preferential expression of HGF in mesenchymal or stromal cells, and c-Met/HGF receptor In epithelial or endothelial cells, the HGF-Met coupling seems to orchestrate dynamic morphogenic processes through epithelial-mesenchymal (or-stromal) interactions for organogenesis and organ regeneration. HGF or HGF gene may well become unique therapeutic tools for treatment of patients with various organ failure, through its actions to reconstruct organized tissue architectures. This review focuses on recently characterized biological and physiological functions integrated by HGF-Met coupling during organogenesis and organ regeneration.

• 대한족부족관절학회지
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• 제1권1호
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• pp.65-73
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• 1997

Hallux valgus deformity has been slowly getting popular in Korea. Many surgical procedures are available for treating the hallux valgus, but it is still controversial for the best treatment. We operated 25 feet(15 patients) of hallux valgus between May. 88 and December. 94. The clinical results were as follow ; 1. Age distribution was 25 to 82, and all female. 10 patients have bilateral hallux valgus. 2. 19 feet were treated by soft tissue procedures only and 6 feet by combined soft tissue and bony procedures. 3. Bunion deformity was recurred in 2 feet (1 Patient) which were treated with modified McBride Method. 4. Lateral sesamoidectomies were performed in 7 feet without development of hallux varus. 5. The cosmetic and functional results were good in 6 cases treated by proximal metatarsal osteotomy. 6. 9 feet had other digits deformities, which need surgical correction. 7. Tightening repair of medial capsule seems to be important for prevention of recurrence of bunion.