• Journal of dental hygiene science
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• v.21 no.4
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• pp.243-250
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• 2021

Background: Endodontic sealers or their toxic components may become inflamed and lead to delayed wound healing when in direct contact with periapical tissues over an extended period. Moreover, an overfilled sealer can directly interact with adjacent tissues and may cause immediate necrosis or further resorption. Therefore, the treatment outcome conceivably depends on the endodontic sealer's biocompatibility and osteogenic potential. This study aimed to evaluate the cell viability and osteogenic effects of four different sealers in osteoblastic cells. Methods: AH Plus (resin-based sealer), Pulp Canal Sealer EWT (zinc oxide-eugenol sealer), BioRoot RCS (calcium silicate-based sealer), and Well-Root ST (MTA-based calcium silicate sealer) were mixed strictly according to the manufacturer's instructions, and dilutions of sealer extracts (1/2, 1/5 and 1/10) were determined. Cell viability was measured using the water-soluble tetrazolium-8 (WST-8) assay. Differentiation was assessed by alkaline phosphatase (ALP) activity and mineralized nodule formation by Alizarin Red S staining. Results: The cell viability of the extracts derived from the sealers excluding Well-Root ST was concentration dependent, with sealer extracts having the least viability at a 1/2 dilution. At sealer extract dilution of 1/10, the test groups showed the same survival rate as that control group, with the exception of BioRoot RCS. Among all experimental groups, BioRoot RCS showed the highest cell viability after 48 hours. The ALP activity was significantly higher in a concentration-dependent manner. Furthemore, all four materials promoted ALP activity and mineralized nodule formation compared to the control at 1/10 dilutions. Conclusion: This is the first study to highlight the differences in biological activity of these four materials. These results suggest that the composition of root canal sealers appears to alter the form of biocompatibility and osteoblastic differentiation.

• Archives of Plastic Surgery
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• v.49 no.2
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• pp.227-239
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• 2022

Complications experienced during lymphatic surgery have not been ubiquitously reported, and little has been described regarding how to prevent them. We present a review of complications reported during the surgical management of lymphedema and our experience with technical considerations to reduce morbidity from lymphatic surgery. A comprehensive search across different databases was conducted through November 2020. Based on the complications identified, we discussed the best approach for reducing the incidence of complications during lymphatic surgery based on our experience. The most common complications reported following lymphovenous anastomosis were re-exploration of the anastomosis, venous reflux, and surgical site infection. The most common complications using groin vascularized lymph node transfer (VLNT), submental VLNT, lateral thoracic VLNT, and supraclavicular VLNT included delayed wound healing, seroma and hematoma formation, lymphatic fluid leakage, iatrogenic lymphedema, soft-tissue infection, venous congestion, marginal nerve pseudoparalysis, and partial flap loss. Regarding intra-abdominal lymph node flaps, incisional hernia, hematoma, lymphatic fluid leakage, and postoperative ileus were commonly reported. Following suction-assisted lipectomy, significant blood loss and transient paresthesia were frequently reported. The reported complications of excisional procedures included soft-tissue infections, seroma and hematoma formation, skin-graft loss, significant blood loss, and minor skin flap necrosis. Evidently, lymphedema continues to represent a challenging condition; however, thorough patient selection, compliance with physiotherapy, and an experienced surgeon with adequate understanding of the lymphatic system can help maximize the safety of lymphatic surgery.

• Journal of Korean Neurosurgical Society
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• v.57 no.4
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• pp.242-249
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• 2015

Objective : The timing of cranioplasty and method of bone flap storage are known risk factors of non-union and resorption of bone flaps. In this animal experimental study, we evaluated the efficacy of cranioplasty using frozen autologous bone flap, and examined whether the timing of cranioplasty after craniectomy affects bone fusion and new bone formation. Methods : Total 8 rabbits (male, older than 16 weeks) were divided into two groups of early cranioplasty group (EG, 4 rabbits) and delayed cranioplasty group (DG, 4 rabbits). The rabbits of each group were performed cranioplasty via frozen autologous bone flaps 4 weeks (EG) and 8 weeks (DG) after craniectomy. In order to obtain control data, the cranioplasty immediate after craniectomy were made on the contralateral cranial bone of the rabbits (control group, CG). The bone fusion and new bone formation were evaluated by micro-CT scan and histological examination 8 weeks after cranioplasty on both groups. Results : In the micro-CT scans, the mean values of the volume and the surface of new bone were $50.13{\pm}7.18mm^3$ and $706.23{\pm}77.26mm^2$ in EG, $53.78{\pm}10.86mm^3$ and $726.60{\pm}170.99mm^2$ in DG, and $31.51{\pm}12.84mm^3$ and $436.65{\pm}132.24mm^2$ in CG. In the statistical results, significant differences were shown between EG and CG and between DG and CG (volume : p=0.028 and surface : p=0.008). The histological results confirmed new bone formation in all rabbits. Conclusion : We observed new bone formation on all the frozen autologous bone flaps that was stored within 8 weeks. The timing of cranioplasty may showed no difference of degree of new bone formation. Not only the healing period after cranioplasty but the time interval from craniectomy to cranioplasty could affect the new bone formation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.3
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• pp.257-265
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• 1999

To investigate the sequential changes in microvascular architecture and osseous regeneration during the bony healing after an application of the guided tissue regeneration method, we made artificial defects measuring $0.7cm{\times}0.3cm$ in size on femoral bones of rats measuring about 200gm and applied non-absorbable TEFE membrane at experimental sites but not at control sites. Then we observed the sequential changes and correlations between new vacuolation and bony regeneration using microvascular corrosion cast method and routine light microscopic observation at 1, 2 and 3 weeks after operation, respectively. The results showed that there were close relationships between regeneration of microvasculature and bone. In early phase, the invasion of granulation tissue at control sites delayed bony regeneration, however, in later phase, there was no remarkable differences in bony regeneration between control and experimental sites. The placement of barrier also affected in revascularization of regenerating bony defects. This is, the experimental sites showed parallel arranged nutritional vessels along long axis with well developed retiform plexus whereas the control revealed vertical invasion of microvasculature from outside of marrow space through bony defects which was also rearrange with time into parallel pattern with a vertical plexus but lesser organized than that of experimental sites. These findings suggest that the reconstruction of regenerating vasculature within the marrow cavity only may be sufficient and/or more be efficient in regeneration of bony defects.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.6
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• pp.397-402
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• 2009

The purpose of this study is to investigate the effects of alendronate and pamidronate on proliferation and the alkaline phosphatase activity of human bone marrow derived mesenchymal stem cells and to relate the results with bisphosphonate related osteonecrosis of the jaw(BRONJ). With the consent of patients with no systemic disease and undergoing iliac bone graft, cancellous bone was collected to obtain human bone marrow derived mesenchymal stem cells through cell culture. 96 well plate were prepared with a concentration of $10^4$cell/ well. Alendronate and pamidronate were added to each well with the concentration of $10^{-6}M$, $10^{-8}M$ and $10^{-10}M$, respectively. Then proliferation capacity of each well was evaluated with the cell counting kit. 24 well plates were prepared with a concentration of $10^5$cell/ml/well and with the bone supplement, alendronate and pamidronate were added with the concentration of $10^{-6}M$, $10^{-8}M$ and $10^{-10}M$, respectively on each plate. The plates were cultured for either 24 or 72 hours. Then the cells were sonicated to measure the alkaline phosphatase activity and protein assay was done to standardize the data for analysis. As the concentration of alendronate or pamidronate added to the culture increased, the proliferation capacity of the cells decreased. However, no statistical significance was found between the group with $10^{-10}M$ of bisphophonate and the control group. Pamidronate was not capable of increasing the alkaline phosphatase activity in all trials. However, alkaline phosphatase activity increased with 24 hours of $10^{-8}M$ of alendronate treatment and with 48 hours of $10^{-10}M$ of alendronate treatment. Cell toxicity increased as the bisphosphonate concentration increased. This seems to be associated with the long half life of bisphosphonate, resulting in high concentration of bisphosphonate in the jaw and thus displaying delayed healing after surgical procedures. Alendronate has shown to increase the alkaline phophatase activity of human bone marrow derived mesenchymal stem cells. However, this data is insufficient to conclude that alendronate facilitates the differentiation of human bone marrow derived mesenchymal stem cells. Further studies on DNA level and animal studies are required to support these results.

• The korean journal of orthodontics
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• v.27 no.6 s.65
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• pp.955-961
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• 1997

Nicotine is one of the major components of cigarette smoking which causes various systemic and local diseases to human body. Mitogenic effects of nicotine to systemic disease are interesting factors in the results of cellular Proliferation especially to vascular and pulmonary tissue or cells. The study of local effects concerns with destruction of tissue and delayed healing rate after various surgical treatment. Platelet-Derived Growth factor(PDGF) and Insulin-like growth factor(IGF) are blown as major mitogens to human PDL cells. The purpose of this study was to investgate the mitogenic effects of nicotine to human PDL cells. We studied the expression of PDGF-$\alpha$ receptor, PDGF-$\beta$receptor, and IGF-l receptor mRNA from the nicotine treated human PDL cells by northern analysis. The experimental groups were divided into different serum($1\%,\;10\%$) and nicotine (100ng/m1,1000ng/m1) concentrations and each group was studied by time course. The results of this study showed upregulation of PDGF-${\alpha},\;{\beta}$ receptor and IGF-l receptor mRNA at 100ng/ml nicotine concentration and $10\%$ serum group to the time course. These results suggest that physiologically attainable nicotine concentrations may stimulate the mitogenic gene synthesis to human PDL cells in vitro.

• Archives of Reconstructive Microsurgery
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• v.8 no.1
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• pp.35-43
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• 1999

There are lots of reconstructive ways like direct closure, skin graft, local flap, regional flap, distant flap, free flap and so on. Microsurgical reconstruction is regarded as the last step in various reconstructive methods. So the failure of this last step causes the troublesome situation for both of patients and surgeon. The purpose of this paper is to investigate the problems in failed free flap surgery and to introduce the strategy of appropriate management in wound of free flap failure. We performed 252 cases of free flap surgeries from May, 1988 to June, 1998. Among these cases, we failed 9 cases of free flaps. Patients' age ranged from 19 to 63. There were 7 males and 2 females. Site of failure were 3 head and neck areas, 2 hands, and 4 lower extremities. However there was no failure in breast, trunk, buttock, and genitalia. 7 patients who had region of head and neck, and lower extremity underwent the second free flap surgery successfully in postoperative 4 to 16 days following debridement of necrotic tissue. However 2 patients who had region in hand were managed with conventional treatment like skin graft and distant flap. Vein grafts were needed in 3 cases of 7 second free flaps, and 1 patients needed sequentially-linked free flaps with two flaps. The second free flaps were inevitable for head and neck area because the large complex wound may cause the lifethreatening condition without immediate coverage with well vascularized flap. Lower extremity also needed second free flap for limb salvage. Hand could be managed with conventional method, even though healing time was quite delayed. We thought second free flap surgery in free flap failure cases should be performed with more careful preoperative evaluation and refined surgery. Success of second free flap surgery could recover the very difficult situation due to previously failed operation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.1
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• pp.10-18
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• 2011

Purpose: The purpose of this study is to find out the effects of bisphosphonates (BPs) on the proliferation and the alkaline phosphatase (ALP) activity of human bone marrow derived mesenchymal stem cells (hMSCs), and thus state its correlation with bisphosphonate related osteonecrosis of the jaw (BRONJ). Methods: hMSCs was obtained by collecting and culturing cancellous bone fragments from a patient undergoing iliac bone graft. Alendronate (Aln) and Pamidronate (Pam), Ibandronate (Ibn) were added to the culture media in the concentration from $10^{-3}$ M to $10^{-11}$ M and cell toxicity, viability were measured. For ALP activity evaluation, Aln and Pam were added to the culture media in the concentration from $5{\times}10^{-7}$ M to $1{\times}10^{-8}$ M and were cultured for 1 week, 2 weeks and 3 weeks. ALP activity data were standardized using protein assay. Control groups were prepared for each examination. Results: Aln, Pam and Ibn all failed to increase the proliferation of hMSCs. With 1 week, 2 weeks of $5{\times}10^{-8}$M of Aln treatment, the ALP activity increased. Pam treatment increased the ALP activity with 2 weeks of $5{\times}10^{-8}$ M and$1{\times}10^{-8}$M. Also Ibn treatment increased the ALP activity with 2 weeks of $5{\times}10^{-8}$ M and $1{\times}10^{-8}$ M. Conclusion: It is considered that BPs are not capable of improving the proliferation of hMSCs. Also, after a transient increase in the ALP activity with the lower concentration of BPs, the activity decreased again. Therefore, in patients on long-term medication of BPs, the proliferation and osteoblast differentiation of hMSCs are restrained, and thus delayed wound healing and increase in BRONJ complications may occur.

• Journal of Chest Surgery
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• v.31 no.10
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• pp.1004-1008
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• 1998

We report a case of heart-lung transplantation in a 32 year-old female with Eisenmenger syndrome secondary to patent ductus arteriosus. She has been suffered from congestive heart failure since June 1996 and repeatedly treated at Intensive Care Unit with intravenous inotropic support since July 1997. Preoperative echocardiography showed a patent ductus arteriosus with right to left shunt, severe regurgitation of tricuspid valve and estimated right ventricular systolic pressure of 100mmHg. The brain-dead donor was an 18 year-old male with head trauma from traffic accident 3 days ago. Heart-lung block procurement was performed at another general hospital and was transported to the Seoul National University Hospital by ambulance. Total ischemic time of the transplanted heart and lung were 249 minutes and 270 minutes, respectively. The immunosuppressive therapy was commenced preoperatively with cyclosporine and azathioprine. Corticosteroid was not used until postoperative 3 weeks in order to avoid infection and delayed healing at the tracheal anastomotic site. The patient was discharged at 31st postoperative day, and has been regularly followed up at outpatient clinic without specific complication. The follow-up bronchoscopy, performed 2 weeks and 4 months after surgery, revealed no evidence of cellular rejection.

• Archives of Reconstructive Microsurgery
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• v.15 no.2
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• pp.92-100
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• 2006

Radial forearm free flap (RFFF) has been established itself as a versatile and widely used method for reconstruction of the head and neck, although it is still criticized for high mortality of donor site. Delayed wound healing, cosmetic deformity, vascular compromise and potentially reduced wrist function have many plastic surgeons hesitate to adapt it as a first choice in micro-reconstruction. To overcome these drawbacks, some techniques for donor-site repair such as V-Y advancement with full thickness skin graft (FTSG), application of artificial dermis ($Terudermis^{(R)}$) or acellular dermal matrix ($AlloDerm^{(R)}$), and double-opposing rhomboid transposition flap have been reported. Authors performed 4 cases of RFFF in old-aged patients of the head and neck cancer from April 2005 to February 2006. We compared the outcomes of donor site of RFFF which were resurfaced with split thickness skin graft (STSG) only and STSG overlying an $AlloDerm^{(R)}$. Patients were all males ranging from 59 to 74 years old (mean, 67.5). Three of them had tongue cancers, and the other showed hypopharyngeal cancer. All cases were pathologically confirmed as squamous cell carcinomas. We included the deep fascia into the flap, so called subfascially elevated RFFF in three cases, and in the other one, we dissected the RFFF suprafascially leaving the fascia intact. The donor site of the suprafascially elevated RFFF was resurfaced with STSG only. Among three of subfascially elevated RFFFs, donor-sites were covered with thin STSG only in one case, and STSG overlying $AlloDerm^{(R)}$ in two cases. All RFFFs were survived completely without any complication. The donor site of the suprafascially elevated RFFF was taken well with STSG only. But, the partial graft loss exposing brachioradialis and flexor carpi radialis muscle was unavoidable in all the subfascially elevated RFFFs irregardless of $AlloDerm^{(R)}$ application. Considering that many patients of the head and neck cancer are in old ages, we believe the RFFF is still a useful and versatile choice for resurfacing the head and neck region after cancer ablation. Its reliability and functional characteristics could override its criticism for donor site in old-aged cancer patients.