• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.1
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• pp.49-58
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• 2008

Objective: The Purpose of the study was to investigate the bone morphogenic protein expression of rhBMP-2(recombinant human bone morphogenic protein-2) as singnaling molecule and ${\beta}-TCP$(Tricalcium phosphate) as a bone substitute and carrier medium of rhBMP-2. Materials and Methods: 16 rabbits divided into 2 group of each 8 rabbit. Two standardized bone defect, round bilateral defect was made in the cranium of the 8 rabbit of first group, and was grafted with $150{\sim}500{\mu}m$ diameter ${\beta}-TCP$ 0.25g in one side, which was soaked with rhBMP-2, and autogenous bone was grafted on another side as a positive control. Second group of 8 rabbit, only ${\beta}-TCP$ was grafted with same size and same manner. After 2, 4, 8, and 12 weeks, specimen was taken for microscopic immunohiostochemical and histomorphometric analysis. Result: Grafting ${\beta}-TCP$ with rhBMP show the early formation of the bone regenerative factor (BMP-4) and more quantity of new bone formation than only use of ${\beta}-TCP$ (8,12 week), even show less new bone formation than autogenous bone. Conclusion : The experimental study result that ${\beta}-TCP$ graft combination with rhBMP-2 as a delivery system is an effective with osteoinductive capacity and biodegradable properties, so that provide clinical availibility of composite use in reconstruction of bony defect.

• Journal of Periodontal and Implant Science
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• v.38 no.sup2
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• pp.273-298
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• 2008

Purpose: The aim of this review is to introduce a novel bone-graft material for hard-tissue regeneration based on the calcium phosphate glass(CPG). Materials and Methods: CPG was synthesized by melting and subsequent quenching process in the system of CaO-$CaF_2-P_2O_5$-MgO-ZnO having a much lower Ca/P ratio than that of conventional calcium phosphates such as HA or TCP. The biodegradability and bioactivity were performed. Effects on the proliferation, calcification and mineralization of osteoblast-like cells were examined in vitro. Influence in new bone and cementum formations was investigated in vivo using calvarial defects of Sprague-Dawley rats as well as 1-wall intrabony defect of beagle dogs. The application to the tissue-engineered macroporous scaffold and in vitro and in vivo tests was explored. Results: The extent of dissolution decreased with increasing Ca/P ratio. Exposure to either simulated body fluid or fetal bovine serum caused precipitation on the surface. The calcification and mineralization of osteoblast-like cells were enhanced by CPG. CPG promoted new bone and cementum formation in the calvarial defect of Sprague-Dawley rats after 8 weeks. The macroporous scaffolds can be fabricated with $500{\sim}800{\mu}m$ of pore size and a three-dimensionally interconnected open pore system. The stem cells were seeded continuously proliferated in CPG scaffold. Extracellular matrix and the osteocalcin were observed at the $2^{nd}$ days and $4^{th}$ week. A significant difference in new bone and cementum formations was observed in vivo (p<0.05). Conclusion: The novel calcium phosphate glass may play an integral role as potential biomaterial for regeneration of new bone and cementum.

• Journal of Biomedical Engineering Research
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• v.17 no.3
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• pp.337-346
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• 1996

The patency of small size vascular grafts is poor, and the blood flow characteristics in the artery graft anastomosis are suspected as one of the important factors influencing intimal hyperplasia. Disturbed flow patterns caused by sixte and compliance mismatch generate unfavorable flow environment which promotes intimal thickening. Tapered vascular yuts are suggested in order to reduce sudden expansion near the anastomosis. The photochromic flow visualization method is used to measure the flout fields in the end-to-end anastomosis model under the carotid and femoral artery flow wave form. The results show that flow disturbance near the anastomosis is diminished in the tapered grafts comparing to the tubular graft. As the divergent ang1e decreases, we can reduce the low and oscillatory wall shear stress zone which is prone to intimal hyperplasia. The flow wave form effects the wall shear rate dis- tribution significantly. The steep deceleration and back flow in the femoral flow wAve form cause low mean wall shear rate and high oscillatory shear index.

• The Journal of Advanced Prosthodontics
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• v.2 no.1
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• pp.7-13
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• 2010

Although most researchers agree that platelet-rich plasma (PRP) is a good source of autogenous growth factors, its effect on bone regeneration is still controversial. The purpose of this study was to evaluate whether increasing angiogenic factors in the human PRP to enhance new bone formation through rapid angiogenesis. MATERIAL AND METHODS. In vitro, the human platelets were activated with application of shear stress, $20\;{\mu}g/ml$ collagen, 2 mM $CaCl_2$ and 10U thrombin/$1\;{\times}\;10^9$ platelets. Level of vascular endothelial growth factor (VEGF) and platelet microparticle (PMP) in the activated platelets were checked. In the animal study, human angiogenic factors-enriched PRP was tested in 28 athymic rat's cranial critical bone defects with $\beta$-TCP. Angiogenesis and osteogenesis were evaluated by laser Doppler perfusion imaging, histology, dual energy X-ray densinometry, and micro-computed tomography. RESULTS. In vitro, this human angiogenic factors-enriched PRP resulted in better cellular proliferation and osteogenic differentiation. In vivo, increasing angiogenic potential of the PRP showed significantly higher blood perfusion around the defect and enhanced new bone formation around acellular bone graft material. CONCLUSION. Angiogenic factor-enriched PRP leads to faster and more extensive new bone formation in the critical size bone defect. The results implicate that rapid angiogenesis in the initial healing period by PRP could be supposed as a way to overcome short term effect of the rapid angiogenesis.

• Archives of Plastic Surgery
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• v.36 no.5
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• pp.571-577
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• 2009

Purpose: The Provision of thin and pliable tissue and the adequate coverage of tendon - gliding surface is necessary for a soft tissue defect of the hand with exposure of bone, tendon and muscle. This report will discuss our experience with anterolateral thigh fascial free flap for the reconstruction of the soft tissue defect of the hand. Methods: Between February 2004 and August 2008, seven patients with full - thickness soft tissue defects of the hand were reconstructed by means of a composite anterolateral thigh fascial free flap. There were soft tissue defects associated with trauma (n=5), scar contracture (n=1) and necrosis due to ischemia (n=1). Flaps were harvested from the anterolateral thigh as adipofascial flaps with only a small sheet of fascia and fatty tissue above it. The fascia and the skin of the donor site was closed directly and delayed split - thickness skin graft was performed. Result: All flaps survived completely. The size of the transferred flap ranged from $2{\times}4cm$ to $5{\times}8cm$. Thin flap coverage was possible without secondary debulking operations. It left minimal donor site morbidity with a linear scar. In one case, the thigh muscle herniation in the donor site was developed. Conclusion: The anterolateral thigh fascial free flap provided thin and pliable tissue which can establish a tendon - gliding mechanism, minimal bulk, minimal donor site morbidity. The disadvantages of this technique were the need for a skin graft and the muscle herniation of donor site.

• FLOWER RESEARCH JOURNAL
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• v.16 no.4
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• pp.321-324
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• 2008

A new yellow graft cactus Gymnocalycium mihanovichii ${\times}$ marsoneri cv. 'Hangseong' was developed by the National Institute of Horticultural &Herbal Science, Rural Development Administration in 2005. 'Hangseong' was selected from a interspecific crossing between Gymnocalycium mihanovichii and G. marsoneri. In 1998, 2 lines of '9834024' and '9834036' were selected from a crossing between G. mihanovichii 'IG-124' and G. marsoneri 'IG-223'. The 2 lines were crossed between them. In 2001, progenies produced from a crossing of the 2 lines were nursed and, finally yellow colored 'Wonkyo G1-169' was selected through 3 times of characteristic trials. It was named as 'Hangseong' and applied for a variety protection. Characteristics of 'Hangseong' is as follows: The color of body and tubercles is yellow. The shape of glove is flat with 7 to 9 deep ribs. Spine is medium straight with long size and brown color. Growth is fast as to reach 49.5 mm in diameter at 10 month after planting. Propagation ability is good as to set as many as 7.2 tubercles. 'Hangseong' is suitable for export to European countries or America. Characteristics of the cultivar can be maintained by vegetative propagation.

• Archives of Plastic Surgery
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• v.46 no.2
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• pp.129-134
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• 2019

Background Nipple-areolar complex (NAC) reconstruction is the final stage of breast reconstruction. Ideal reconstruction of the NAC requires symmetry in position, size, shape, texture, pigmentation, and permanent projection, and although many technical descriptions of NAC reconstruction exist in the medical literature, there is no gold standard technique. The technique devised by the authors is very versatile, with excellent results, and it enables 1-step reconstruction with optimal results in terms of shape and nipple projection. Methods Our technique consists of a combination of modified local flaps and a full-thickness skin graft. Patients were observed for 18 months to estimate the amount of retraction. This procedure was performed in 40 patients, four of them bilaterally. The duration of the follow-up was 30 months. Complications occurred in 10% of patients, and included infections (5%), ischemia (2.5%), and hematoma (2.5%). Results No cases of total nipple necrosis were reported. The NAC shape remained optimal in all cases, with a very small reduction of the vertical and horizontal diameters of the areola, which maintained its designed round shape well, and negligible retraction in the diameter and projection of the nipple. Conclusions The oval technique represents a major step forward, involving a combination of existing techniques, such as the C-V flap and the cutaneous graft, to achieve excellent results regarding areola shape and nipple projection, significantly reducing the cases of nipple ischemia. These results were substantially obtained through subcutaneous equatorial sutures, skin grafting, and flattening of the apexes of the flap.

• Archives of Plastic Surgery
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• v.48 no.6
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• pp.691-698
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• 2021

Background The reverse sural artery (RSA) flap is widely used for lower extremity reconstruction. However, patients sometimes suffer from donor site complications such as scar contracture and paresthesia, resulting in dissatisfaction with the aesthetic outcomes. This study investigated the characteristics of donor site morbidity associated with RSA flaps and described our experiences of dealing with complications by performing resurfacing surgery using thoracodorsal artery perforator (TDAP) flaps. Methods From April 2008 to August 2018, a total of 11 patients underwent contracture release and resurfacing surgery using TDAP flaps due to donor morbidity associated with RSA flaps. All affected donor sites were covered with a skin graft, the most common of which was a meshed split-thickness skin graft (six cases). Results Eight of the 11 patients (72.7%) suffered from pain and discomfort due to scar contracture, and seven (63.6%) complained of a depression scar. The donor sites were located 6.3±4.1 cm below the knee joint, and their average size was 140.1 cm². After resurfacing using TDAP flaps, significant improvements were found in the Lower Extremity Functional Scale (LEFS) scores and the active and passive ranges of motion (AROM and PROM) of the knee joint. The LEFS scores increased from 45.1 to 56.7 postoperatively (P=0.003), AROM increased from 108.2° to 118.6° (P=0.003), and PROM from 121.4° to 126.4° (P=0.021). Conclusions Planning of RSA flaps should take into account donor site morbidity. If complications occur at the donor site, resurfacing surgery using TDAP flaps achieves aesthetic and functional improvements.

• Archives of Plastic Surgery
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• v.49 no.6
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• pp.704-709
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• 2022

Background The scar alopecia after cranioplasty (SAC) may decrease the patient's quality of life. We have treated SAC using follicular unit extraction (FUE). The aim of this study was to discuss that efficacy of FUE and how much hair follicular unit (FU) should be transplanted intraoperatively for the treatment of SAC. Methods We treated 10 patients (4 men and 6 women) who had SAC using FUE. Results The average age, alopecia size, and intraoperative hair density on the graft area were 29.8 ± 12.1 years, 29.8 ± 44.5 cm², and 34.6 ± 11.8 FU/cm², respectively. One year postoperatively, the average hair survival rate on the graft area was 66.3 ± 6.1%. Hair appearance was rated as good in six, fair in three, and poor in one. Among patients whose 1-year postoperative hair density was ≥ 20 FU/cm², five of six patients achieved good results. However, among patients whose 1-year postoperative hair density was < 20 FU/cm², all four patients achieved fair or poor results. The postoperative hair density was significantly higher in patients whose 1-year postoperative hair density was ≥ 20 FU/cm² than in patients whose 1-year postoperative hair density was< 20 FU/cm². The rate of achieving fair or poor results was significantly higher if the postoperative hair density was < 20 FU/cm² than if it was ≥ 20 FU/cm² (p = 0.047). Conclusions FU excision is useful for the treatment of scar alopecia after craniotomy. Our results suggest that the 1-year postoperative hair density should exceed 20 FU/cm² to achieve good outcomes.

• Journal of Periodontal and Implant Science
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• v.52 no.6
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• pp.466-478
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• 2022

Purpose: Coronally advanced split-or full-thickness (CAST or CAFT) flaps in combination with subepithelial connective tissue grafts (SCTGs) are commonly used in root-coverage procedures despite postoperative pain and bleeding from the graft donor site. Therefore, the modified vestibular incision subperiosteal tunnel access procedure (VISTAX) uses a novel collagen matrix (VCMX) instead of autogenous tissue to address the limitations associated with autogenous tissue grafting. This retrospective study compared the clinical outcomes of VISTAX to the results obtained after using a CAST or CAFT flap in combination with SCTG for root coverage. Methods: Patients with single or multiple adjacent recession I/II defects were included, with 10 subjects each in the VISTAX, CAFT, and CAST groups. Defect coverage, keratinized tissue width, esthetic scores, and patients' perceived pain and dentinal hypersensitivity (visual analogue scale [VAS]) were assessed at baseline, 3 months, and 6 months. Results: All surgical techniques significantly reduced gingival recession (P<0.0001). Defect coverage, esthetic appearance, and the reduction in dentinal hypersensitivity were comparable. However, the VAS scores for pain were significantly lower in the VISTAX group than in the CAFT and CAST groups, which had similar scores (P<0.05). Furthermore, the clinical results of VISTAX and CAFT/CAST generally remained stable at 6 months. Conclusions: The clinical outcomes of VISTAX, CAFT, and CAST were comparable. However, patients perceived significantly less pain after VISTAX, indicating a potentially higher patient acceptance of the procedure. A prospective trial with a longer follow-up period and a larger sample size should therefore evaluate VISTAX further.