• Archives of Reconstructive Microsurgery
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• v.17 no.2
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• pp.82-86
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• 2008

Purpose: Soft tissue defect can occur on the posterior aspect of the elbow after trauma or fracture fixation. To cover the defect and maintain elbow functions, various flap surgeries including latissimus dorsi muscle flap, lateral arm flap and radial forearm flap can be performed. We present the clinical results of transposition lateral arm flap for coverage of the elbow defect and discuss the cause of posterior soft tissue necrosis after fracture fixation. Materials and Methods: Two patients who had posterior soft tissue defect of the elbow after open reduction of the fractures around the elbow were treated with transposition lateral arm flap. The mean size of skin defect was 20 $cm^2$. The flap was elevated with posterior radial collateral artery pedicle and transposed to the defect area. Donor defect was covered with split thickness skin graft. The elbow was immobilized for 1 week in extended position and active range of motion was permitted. Results: All two cases of transposition lateral arm flap survived without marginal necrosis. The average range of motion of the elbow was 10~115 degrees. Mayo elbow performance score was 72 and Korean DASH score was 23. Conclusion: When elbow fractures are fixed with three simultaneous plates and screws, skin necrosis can occur on the posterior aspect of the elbow around olecranon area. If the size of skin defect is relatively small, transposition lateral arm flap is very useful option for orthopaedic surgeons without microsurgical technique.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.4
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• pp.485-489
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• 2008

Basal cell nevus syndrome is a hereditary disease of an autosomal dominant trait with variable conditions such as basal cell carcinomas of the skin, deformity of rib, fusion of vertebrae, mental retardation, hypertelorism, and multiple odontogenic keratocysts. A 32 years old man with pus discharge from fistula on the vestibule of left upper 1st molar visited to Chosun University Dental Hospital. Radiographic evaluation revealed multiple maxillary and mandibular cysts that had multilocular radiolucency on left mandibular body area, thining of inferior border of left border of ramus and well defined unilocular radiolucency above right upper 1st and 2nd molar and from left upper 1st premolar to 2nd molar. In chest PA view, he had a forked rib in the left 4th rib and in skull PA view the calcification of falx cerebri was observed. There was not any skin lesion. After the preliminary evaluation, the patient was diagnosed with basal cell nevus syndrome and he underwent marsupialization for decreasing the size of cystic lesion and came to hospital for dressing 3days a week. As time goes by, the size of lesion decreased. So, one and half year after marsupialization, he underwent cyst enucleation and iliac bone graft for the mandibular lesion and buccal fat pad grafts for the maxillary lesions. After the surgery, the patient experienced normal healing without any complications and he is on long-term follow-up.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.7
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• pp.940-945
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• 2021

Future network architectures such as Named Data Networking (NDN) were born to change the way data can be transmitted from current host-centric network technologies to information-centric network technologies. Recently, many studies are being conducted to graft Vehicular NDN to the communication network technology of smart vehicles including connected vehicles. Explosion of data traffic due to Interest/Data packet broadcasting in Vehicular NDN environment is a very important problem to be solved in order to realize VNDN-based data communication. In this paper, the generation of data packet copies according to the increase in network size, vehicle speed, and frequency of interest packets in VNDN network is simulated and evaluated using ndnSIM, in order to show how severe the data broadcast storm phenomenon. The CDP(Copies of Data Packets) increased proportionally in the increase of network size or Interest frequency.

• Journal of Periodontal and Implant Science
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• v.52 no.4
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• pp.325-337
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• 2022

Purpose: The aim of this study was to investigate the effect of (1) the size of the bony access window and (2) collagen membrane coverage over the window in sinus floor elevation in a rabbit sinus model. Methods: Small bony access windows (SW; ø 2.8 mm) were made in 6 rabbits and large windows (LW; ø 6 mm) in 6 other rabbits. Both sinuses in each rabbit were allocated to groups with or without coverage of a collagen membrane (CM) on the window, resulting in 4 groups: SW, LW, SW+CM, and LW+CM. After 4 weeks of healing, micro-computed tomographic, histologic, and histomorphometric analyses were performed. Results: Bony healing in the window area was incomplete in all groups, but most bone graft particles were well confined in the augmented cavity. Histologically, the pattern of new bone formation was similar in all groups. Histomorphometrically, the percentage of newly formed bone was greater in the groups with CM than in the groups without CM, and in the groups with SW than in the groups with LW (12.92%±6.40% in the SW+CM group, 4.21%±7.73% in the SW group, 10.45%±4.81% in the LW+CM group, 11.77%±3.83% in the LW group). The above differences were not statistically significant (P>0.05). Conclusions: The combination of a small bony access window and the use of a collagen membrane over the window favored new bone formation compared to other groups, but this result should be further investigated due to the limitations of the present animal model.

• Archives of Plastic Surgery
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• v.49 no.6
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• pp.729-739
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• 2022

Cranioplasties are common procedures in plastic surgery. The use of tissue expansion (TE) in staged cranioplasties is less common. We present two cases of cranioplasties with TE and systematically review literature describing the use of TE in staged cranioplasties and postoperative outcomes. A systematic review was performed by querying multiple databases. Eligible articles include published case series, retrospective reviews, and systematic reviews that described use of TE for staged bony cranioplasty. Data regarding study size, patient demographics, preoperative characteristics, staged procedure characteristics, and postoperative outcomes were collected. Of 755 identified publications, 26 met inclusion criteria. 85 patients underwent a staged cranioplasty with TE. Average defect size was 122 cm², and 30.9% of patients received a previous reconstruction. Average expansion period was 14.2 weeks. The most common soft tissue closures were performed with skin expansion only (75.3%), free/pedicled flap (20.1%), and skin graft (4.7%). The mean postoperative follow-up time was 23.9 months. Overall infection and local complication rates were 3.53 and 9.41%, respectively. The most common complications were cerebrospinal fluid leak (7.1%), hematoma (7.1%), implant exposure (3.5%), and infection (3.5%). Factors associated with higher complication rates include the following: use of alloplastic calvarial implants and defects of congenital etiology (p = 0.023 and 0.035, respectively). This is the first comprehensive review to describe current practices and outcomes in staged cranioplasty with TE. Adequate soft tissue coverage contributes to successful cranioplasties and TE can play a safe and effective role in selected cases.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.5
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• pp.366-374
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• 2010

Introduction: This study evaluated the capability of silk fibroin (SF) and recombinant human bone morphogenetic protein-2 loaded SF (SF-BMP) as a bone defect replacement matrix when grafted in a calvarial bone defect of rats in vivo. Materials and Methods: A total 70 calvarial critical size defects (5.0 mm in diameter) made on 35 adult female Sprague-Dawley rats were used in this study. The defects were transplanted with (1) rhBMP-2 loaded silk fibroin graft (SF-BMP: 0.8+$10\;{\mu}g$), (2) Silk fibroin (SF: $10\;{\mu}g$), and (3) no graft material (Raw). The samples were evaluated with soft x-rays, alkaline phosphatase activity, calcium/phosphate quantification, histological and histomorphometric analysis at postoperative 4 and 8 weeks. Results: The SF-BMP group ($48.86{\pm}14.92%$) had a significantly higher mean percentage bone area than the SF group ($24.96{\pm}11.01%$) at postoperative 4 weeks.(P<0.05) In addition, the SF-BMP group ($40.01{\pm}12.43%$) had a higher % bone area at postoperative 8 weeks than the SF group ($33.26{\pm}5.15%$). The mean ratio of gray scale levels to the host bone showed that the SF-BMP group ($0.67{\pm}0.08$) had a higher mean ratio level than the SF group ($0.61{\pm}0.09$) at postoperative 8 weeks. These differences were not statistically significant.(P=0.168 and P=0.243, respectively) The ratio of the calcium and phosphate contents of the SF-BMP ($0.93{\pm}0.22$) group was lower than that of the SF ($1.90{\pm}1.42$) group at postoperative 4 weeks. However, the SF-BMP group ($0.75{\pm}0.31$) had a higher Ca/$PO_4$ ratio than the SF ($0.68{\pm}0.04$) at postoperative 8 weeks. These differences were not statistically significant.(P=0.126 and P=0.627, respectively) For the bone-specific alkaline phosphatase (ALP) activity, which is recognized as a reliable indicator of the osteoblast function, the SF-BMP ($23.71{\pm}8.60\;U/L$) groups had a significantly higher value than the SF group ($12.65{\pm}6.47\;U/L$) at postoperative 4 weeks.(P<0.05) At postoperative 8 weeks, the SF-BMP ($21.65{\pm}10.02\;U/L$) group had a lower bone-specific ALP activity than the SF group ($16.72{\pm}7.35\;U/L$). This difference was not statistically significant.(P=0.263) For the histological evaluation, the SF-BMP group revealed less inflammation, lower foreign body reactions and higher bone healing than the SF group at postoperative 4 and 8 weeks. The SF group revealed more foreign body reactions at postoperative 4 weeks. However, this immunogenic reaction decreased and the remnant of grafted material was observed at postoperative 8 weeks. For histomorphometric analysis, the SF-BMP group had a significantly longer bone length to total length ratio than those of the SF group at postoperative 4 and 8 weeks.(P<0.05) Conclusion: The rhBMP-2 loaded silk fibroin graft revealed fewer immunoreactions and inflammation as well as more new bone formation than the pure silk fibroin graft. Therefore, silk fibroin may be a candidate scaffold for tissue engineered bone regeneration.

• Journal of Chest Surgery
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• v.41 no.4
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• pp.417-422
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• 2008

Background: The aim of this study is to evaluate the long term results of creating various right ventricle to pulmonary artery conduits for treating complex congenital heart disease. Material and Method: Between June 1986 and July 2006, we retrospectively reviewed 245 patients who underwent reconstruction of the right ventricular outflow tract with various kinds of conduits. 410 operations were done in 245 patients, the mean age at operation was $3.2{\pm}4.9$ years (range: 7 days$\sim$45 years) and the mean body weight was $12.5{\pm}8.7\;kg$ (range: $2.4\sim76.3\;kg$). Result: We used the following conduits: Polystan conduit, Shelhigh conduit, Carpenter-Edward conduit, Dacron graft with an artificial valve, valveless Gore Tex vascular graft, homograft and hand-made bovine or autologous pericardial conduit. The mean follow up duration was $6.3{\pm}5.2$ years. Redo operation for RV-PA conduit dysfunction was performed in 131 patients, a second redo was done in 31 and a third redo was done in 3. The reoperation free rates were 67.3%, 48.5% and 39.4% for 5 years, 10 years and 15 years, respectively. The homograft showed the best durability, followed by the Dacron graft with artificial valve and the Carpentier-Edward conduit. The larger sized conduit showed better durability. Conclusion: The homograft showed lowest reoperation rate and a smaller size of conduit showed the highest reoperation rate. The reoperation rate for the RV-PA conduit was about 35% at 5 years, so it is mandatory to develop the more durable conduit for RV outflow.

• Journal of Chest Surgery
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• v.50 no.6
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• pp.436-442
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• 2017

Background: Dissection flaps in acute type A aortic dissection typically extend into the root, most frequently into the non-coronary sinus (NCS). The weakened root can be susceptible not only to surgical trauma, but also to future dilatation because of its thinner layers. Herein, we describe a new technique that we named the "neo-adventitia" technique to strengthen the weakened aortic root. Methods: From 2012 to 2016, 27 patients with acute type A aortic dissection underwent supracommissural graft replacement using our neo-adventitia technique. After we applied biologic glue between the dissected layers, we wrapped the entire NCS and the partial left and right coronary sinuses on the outside using a rectangular Dacron tube graft that served as neo-adventitia to reinforce the dissected weakened wall. Then, fixation with subannular stitches stabilized the annulus of the NCS. Results: There were 4 cases of operative mortality, but all survivors were discharged with aortic regurgitation (AR) classified as mild or less. Follow-up echocardiograms were performed in 10 patients. Of these, 9 showed mild or less AR, and 1 had moderate AR without root dilatation. There were no significant differences in the size of the aortic annulus (p=0.57) or root (p=0.10) between before discharge and the last follow-up echocardiograms, and no reoperations on the aortic roots were required during the follow-up period. Conclusion: This technique is easy and efficient for reinforcing and stabilizing weakened roots. Furthermore, this technique may be an alternative for restoring and maintaining the geometry of the aortic root. An externally reinforced NCS could be expected to resist future dilatation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.1
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• pp.22-29
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• 2008

Purpose: The purpose of this study is to test the efficacy of various methods of fat harvesting in animal model by viability comparison with assay including cell counting, MTT assay, and histologic evaluation. Materials and methods: New Zealand white rabbits experiments were used. Groin fat pads were subjected to different harvest method varying ingredients of solution(Experiment 1: T1 solution= lidocaine 1000mg/L, epinephrine 1mg/L, sodium bicarbonate 10mgEq/L, Triamcinolone 10mgEq/L; T2 solution=lidocaine 1000mg/L, epinephrine 1mg/L, sodium bicarbonate 0mgEq/L, Triamcinolone 0mgEq/L) and pressure exerted on harvesting with Luer-Lock syringe connected to suction cannula.(Experiment 2: P1 group=3cc intermittent pressure; P2 group=10cc sustained pressure) Fat cell viability was assessed with cell counting with a hemocytometer, MTT assay, and histologic evaluation. Results: Experiment 1 Cell count: T1=2.4/3.4/4.2, T2=9.6/8.4/7.2($\times10^5$ per mL); MTT assay: T1=0.516/0.41/0.453/0.412/0.421, T2=0.925/0.765/0.54/0.634/0.614 in 21 days(absorbance); Histology: T1 showed elongated and, different in size and shape, and ruptured adipocytes with only a few normal adipocytes whereas T2 showed central core of fat with almost intact fat cells Experiment 2 Cell count: P1=1.2/3.2/4.2, P2=1.2/2.4/3.8($\times10^5$ per mL); MTT assay:P1=0.256/0.245/0.258/0.21/0.264, P2=0.12/0.231/0.245/0.313/0.281 in 21 days(absorbance); Histology: P1 showed somewhat evenly distributed normal-looking fat cells and P2 showed relatively irregular shape of fat cells with small blood vessel amongst adiopocytes. Conclusion: Viability was higher in ‘modified tumescent solution’without sodium bicarbonate and triamcinolone and we also found no significantly different viability between using intermittent pressure and using sustained pressure. But in terms of initial viability of fat cell, we can assume that lower intermittent pressure would make better clinical results.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.42.1-42.7
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• 2016

Background: The purpose of this retrospective study was to evaluate the clinical utility of an implant with a sandblasted, large-grit, acid-etched (SLA) surface and internal connection. Methods: Six patients who received dental implants in the Department of Oral and Maxillofacial Surgery, Chonnam National University Dental Hospital, were analyzed by factors influencing the success rate and marginal bone loss. Factors included patient's age, sex, implant installation site, whether bone graft was done, type of bone graft materials, approaching method if sinus lift was done, and the size of the fixture. In addition, the marginal bone loss was analyzed by using a radiograph. Results: All implants were successful, and the cumulative survival rate was 100 %. Average marginal bone loss of 6 months after the installation was 0.52 mm and 20 months after the functional loading was 1.06 mm. Total marginal bone resorption was 1.58 mm on average. There was no statistically significant difference in mesial and distal marginal bone loss. Conclusions: The short-term clinical success rate of the implant with an SLA surface and internal connection was satisfactory. Moreover, the marginal bone loss was also consistent with the implant success criteria.