• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.3
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• pp.229-236
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• 2009

Purpose: Some recent literatures report that it is possible to recover defected areas caused by enucleation of relatively large jaw cysts without using bone grafts. The aim was to find out whether spontaneous recovery of defected area with time occurred and what the contributing factors were. Materials and methods: In total, 194 patients were considered as patients. Out of these 194 patients, 74 patients who had no wound dehiscence and who were available for follow-up studies were selected. They were classified into two groups according to the size of radiolucent area in the preoperative panoramic radiographs: in one group, it was larger than $3{\times}4cm$, while in the other group, it was smaller than $3{\times}4cm$. Follow-up panoramic radiographs were taken immediately after the surgery, then after 3, 6, 9 and 12 months. On those radiographs, changes in size and density of the defected areas were observed using the Gray-level histogram of Adobe photoshop v7.0. Correlation between bone regeneration and factors such as the type and size of the cysts, age, sex, site of the cysts and systemic disease was evaluated using the General repeated measure and Mann-Whitney Test. Results: Analyses of panoramic radiographs showed that the recovery of radiopacity after 12 months was more than 97% on average in defected areas that were smaller than $3{\times}4cm$. in the defected areas that were larger than $3{\times}4cm$, considerable portion showed recovery of radiopacity. No statistically significant change was observed in bone density according to the type of cysts. Young patients under 20 years of age with highly active metabolism presented more significant bone regeneration than patients over 20 years of age. Bone regeneration was more hampered in patients who had medical disease, compared with patients who didn’t have any medical problem. No statistically significant change was seen in bone density according to sex. Changes in bone density according to the site of cysts such as maxilla, mandible, anterior or posterior region were not considered to be significant. Conclusion: Analyses of panoramic radiographs suggest that in approximately 12 months after the enucleation of cysts, clinically acceptable spontaneous bone regeneration can be observed even though normal bone graft procedures have not been applied.

• Archives of Craniofacial Surgery
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• v.17 no.4
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• pp.190-197
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• 2016

Background: The cheek rotation flap has sufficient blood flow and large flap size and it is also flexible and easy to manipulate. It has been used for reconstruction of defects on cheek, lower eyelid, or medial and lateral canthus. For the large defects on central nose, paramedian forehead flap has been used, but patients were reluctant despite the remaining same skin tone on damaged area because of remaining scars on forehead. However, the cheek flap is cosmetically superior as it uses the adjacent large flap. Thus, the study aims to demonstrate its versatility with clinical practices. Methods: This is retrospective case study on 38 patients who removed facial masses and reconstructed by the cheek rotation flap from 2008 to 2015. It consists of defects on cheek (16), lower eyelid (12), nose (3), medial canthus (3), lateral canthus (2), and preauricle (2). Buccal mucosa was used for the reconstruction of eyelid conjunctiva, and skin graft was processed for nasal mucosa reconstruction. Results: The average defect size was $6.4cm^2$, and the average flap size was $47.3cm^2$. Every flap recovered without complications such as abnormal slant, entropion or ectropion in lower eyelid, but revision surgery required in three cases of nasal side wall reconstruction due to the occurrence of dog ear on nasolabial sulcus. Conclusion: The cheek rotation flap can be applicable instead of paramedian forehead flap for the large nasal sidewall defect reconstruction as well as former medial and lateral canthal defect reconstruction.

• Journal of Periodontal and Implant Science
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• v.38 no.2
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• pp.163-170
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• 2008

Purpose: Biphasic calcium phosphates have been of great interest recently. Mixing adequate ratios of hydroxyapatite(HA) and beta-tricalcium phosphate($\beta$-TCP) allowed to control the resorption rate without distorting its osteoconductive property. This study evaluated the bone formation effect of newly developed biphasic calcium phosphate(BCP) in calvarial defect of rabbits. Materials and Methods: 6 male New Zealand rabbits were used. Four defects with 8mm in diameter were created on each animal. BCP with HA/$\beta$-TCP ratio of 7:3 and particle size of $0.5{\sim}1.0\;mm$ was used as the test group and bovine bone with $0.25{\sim}1.0\;mm$ particle size, as the control group. Both test and control group materials were randomly implanted in the calvarial defects and were covered witha polymer membrane. The animals were sacrificed after 12, 24, and 48 weeks of implantation under general euthanasia. Resin blocks were obtained and were stained by masson's trichrome for histological observation. Results: Overall results were uneventful without any defect exposure or inflammation. The amount of new bone formation and bone maturity increased with increase in healing period at both groups. New bone in test group was mostly formed along the material particle surrounded by osteoblasts, and observation of osteoblastic stream was also present. Bone maturity increased as it was closer to thedefect margins. Under the same healing period, the test group showed more bone formation than the control group with more stable bovine bone particles remaining even after 48 weeks, whereas considerable resorption took place in BCP. Almost total defect closure was observed in test group with new bone formation in the central part of the defect. However, limited new bone formation was observed in the control group. Conclusion: Within the limits of the study, the present study reveals the newly developed BCP to be a good osteoconductive material. However, further studies are needed to be conducted in a different study model with a larger sample size.

• Polymer(Korea)
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• v.32 no.3
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• pp.246-250
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• 2008

Colloidal stability of the biodegradable nanoparticle was characterized by measuring the variation of particle size with time using photon correlation spectroscopy. Three kinds of polymers, namely, poly(D,L-lactide-co-glycolide)(PLGA), PLGA/poly(L-lactide) blends, and PLGA/poly(L-lactide)-g-poly(ethylene glycol) blends were used as matrix material for nanoparticle preparation. Nanoparticles were prepared with or without using poly(vinyl alcohol)(PVA) as suspension stabilizer to evaluate the condition of preparation. Nanoparticles from the blend of amphiphilic graft copolymer with short poly(ethylene glycol) chain and PLGA maintained suspension for 1 day when protein stock solution was introduced. This is somewhat improvement in colloidal stability against protein adsorption compared with that of nanoparticles without PEG moiety. Suspension stabilizer, PVA, had a significant effect on the colloidal stability against freezing and protein adsorption which led to coagulation of nanoparticles. It is important to consider effect of suspension stabilizer as well as materials used to prepare nanoparticle on the colloidal stability.

• Archives of Plastic Surgery
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• v.38 no.5
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• pp.699-702
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• 2011

Purpose: Venous stasis ulcer is the most severe form of chronic venous insufficiency and this commonly appears in the lower limb. Pharmacological therapy, reconstruction of the venous system, surgical management, cellular therapy and compression therapy are known as the treatments of venous stasis ulcer, but relapses are common, which make it a typical chronic wound. We report here on a case of recurrent venous stasis ulcer that healed with compression therapy without any other treatment. Methods: A 35-year-old man with a 13 years history of venous stasis had developed an ulcer on the distal third portion of the lower left limb which was developed 12-year before enrollment in this study. He had been treated with vacuum assist closure, 2 times of cell therapy and 3 times of skin graft for 8 years, but the lesion recurred. From November, 2008 compression therapy was done with the 3M $Coban^{TM}$ 2 Layer Compression System (3M, St. Paul, USA). The ulcer at that time was oval shaped and $3{\times}4$ cm in size. A comfort layer bandage was applied from the proximal phalanx of the great toe to the knee. A compression layer bandage was applied on the previous layer with it being overlapped one half the width of the comfort layer bandage. The dressing was changed every 4 days and the change was recorded with photography. Results: A total of 12 $Coban^{TM}$ 2 Layer Compression Systems were used. The size of the ulcer decreased to $2.5{\times}2.5$ cm in one month, to $2{\times}2$ cm in 2 months, it was $1{\times}1.8$ cm in size at 3 months and it completely healed in 4 months. Conclusion: The venous stasis ulcer was completely healed using the 3M $Coban^{TM}$ 2 Layer Compression System. This method was easy to apply, made the patient comfortable and it provided an excellent compression effect. As in the previous studies, this compression therapy has been proven to play an important role for the treatment and prevention of venous stasis ulcer.

• Journal of Chest Surgery
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• v.30 no.4
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• pp.378-382
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• 1997

To evaulate the effectiveness and risk factors for shunt failure of the Blalock-Taussig shunt in neonates, we analyzed the 21 neonates who were undergone Blalok-Taussig shunt operation at Dong-A University Hospital from December 1991 to Feburary 1996. We evaluated operative mortality, patency of the shunt. and distortion of pulmonary artery. We also determined the risk factors for the shunt failure. Age at operation was from 1 day to 30 days(mean 11.7 days). We ghts were 2.4 to 4.5kg(mean 3.1 kg). The underlying lesions included severe tetralogy of Fallot with pulmonary stenosls or atresia(N=11) and single ventricle varieties with. pulmonary stenosis or atresia(N=10). Prostaglandin El was given in 13 neonates prior to operation. The mean preoperative(prior to prostaglandin El therapy) and postoperative arterial oxygen tension were 30.1 mmHg and 46.3 mmHg respectively(P(0.01). The shunt was performed through a left thoracotomy in 11 patients and through a right thoracotomy In 10. A 5 mm graft was used in 15 patients and a 4 mm graft in 6 patients. The incidence of early shunt occlusion was 9.5%(2 patients). The hospital mortality was 9.5%(2 patients with early shunt occlusion). Univariate analysis revealed that body weight of 2.6 kg or less(p=0.021), pulmonary artery size of 3mm or less(p=0.008), and 4 mm graft (p=0.021) were risk factors predictive of early shunt failure. The patency rate of the shunt in hospital survivors was 100% at mean ollow-up of ll.3 months(There was not death or reoperation related to shunt failure). 10 patients were catheterized during postoperative follow-up. There was no significant distorsion of pulmonary artery. So we concluded that the modified Blalock-Taussig shunt in neonates was excellent in the hospital survivors.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.42 no.2
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• pp.77-83
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• 2016

Objectives: To evaluate the effectiveness of regenerative tissue matrix (Alloderm) as an oral layer for difficult anterior palatal fistula closure. Materials and Methods: The authors have tested the feasibility of a novel surgical technique of adding a regenerative tissue matrix (Alloderm) as an oral layer for closure of recalcitrant large anterior palatal fistulae and report the outcome of the first 12 patients in this pilot study. Patients with recurrent large fistula who otherwise would require either a local pedicled flap, free flap, or an obturator were treated with this technique and followed up for at least 6 months to monitor the progress of healing. Results: Of the 12 patients, 8 patients (66.7%) had complete closure of the fistula, and 2 patients (16.7%) showed reduction in size of the fistula to the extent that symptoms were eliminated, for an overall success rate of 83.3% (10/12 patients). Premature graft loss and recurrence of the fistula were noted in 2 patients (16.7%). Conclusion: Alloderm provided an adequate barrier allowing healing to occur unimpeded and allowed closure of the palatal fistula. In our experience, this new technique using regenerative tissue matrix as an adjunct to the oral layer in large anterior palatal fistula has an advantage compared to other more invasive complex procedures and has been shown to provide satisfactory results.

• Journal of Chest Surgery
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• v.50 no.6
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• pp.430-435
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• 2017

Background: Mycotic aortic aneurysms are rare and life-threatening. Unfortunately, no established guidelines exist for the treatment of patients with mycotic aortic aneurysms. The purpose of this study was to evaluate the midterm outcomes of the open repair of mycotic thoracic and thoracoabdominal aneurysms and suggest a therapeutic strategy. Methods: From 2006 to 2016, 19 patients underwent open repair for an aortic aneurysm. All infected tissue was extensively debrided and covered with soft tissue. We recorded the clinical findings, anatomic location of the aneurysm, bacteriology results, antibiotic therapy, morbidity, and mortality for these cases. Results: The median age was $62{\pm}7.2years$ (range, 16 to 78 years), 13 patients (68%) were men, and the mean aneurysm size was $44.5{\pm}4.9mm$. The mean time from onset of illness to surgery was $14.5{\pm}2.4days$. Aortic continuity was restored in situ with a Dacron prosthesis (79%), homograft (16%), or Gore-Tex graft (5%). Soft-tissue coverage of the prosthesis was performed in 8 patients. The mean follow-up time was $43.2{\pm}11.7months$. The early mortality rate was 10.5%, and the 5-year survival rate was $74.9%{\pm}11.5%$. Conclusion: This study showed acceptable early and midterm outcomes of open repair of mycotic aneurysms. We emphasize that aggressive intraoperative debridement with soft-tissue coverage results in a high rate of success in these high-risk patients.

• Journal of Preventive Medicine and Public Health
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• v.49 no.4
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• pp.230-239
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• 2016

Objectives: We aimed to evaluate the effect of geographic units of analysis on measuring geographic variation in medical services utilization. For this purpose, we compared geographic variations in the rates of eight major procedures in administrative units (districts) and new areal units organized based on the actual health care use of the population in Korea. Methods: To compare geographic variation in geographic units of analysis, we calculated the age-sex standardized rates of eight major procedures (coronary artery bypass graft surgery, percutaneous transluminal coronary angioplasty, surgery after hip fracture, knee-replacement surgery, caesarean section, hysterectomy, computed tomography scan, and magnetic resonance imaging scan) from the National Health Insurance database in Korea for the 2013 period. Using the coefficient of variation, the extremal quotient, and the systematic component of variation, we measured geographic variation for these eight procedures in districts and new areal units. Results: Compared with districts, new areal units showed a reduction in geographic variation. Extremal quotients and inter-decile ratios for the eight procedures were lower in new areal units. While the coefficient of variation was lower for most procedures in new areal units, the pattern of change of the systematic component of variation between districts and new areal units differed among procedures. Conclusions: Geographic variation in medical service utilization could vary according to the geographic unit of analysis. To determine how geographic characteristics such as population size and number of geographic units affect geographic variation, further studies are needed.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.2
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• pp.177-183
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• 1996

With the increasing esthetic requirement in orthognathic surgeries, midfacial corrective surgeries were developed to improve the paranasal depression. Augmentation with autogenous bones has long been the standard in facial reconstruction, however limited graft availability, donor site morbidity, and difficulties in 3-dimensional shaping were led to limited use. Porous high density polyethylene$(Medpor{(R)})$ was introduced in the 1970s as an alloplastic implants. It can be used in various size and shapes, and shortend operation time. The purpose of this study is to determine, by means of cephalometrics, the degree of long term stability and gaining of the overlying soft tissue thickness. The results were as followings : 1. There was no evidence of foreign body reaction, infection, and tissue necrosis. 2. $(Medpor{(R)})$ implants had an advantage of clinical use ; easy to contour and adapt to obtain a precise 3-dimensional construction. 3. Cephalometric study of 16 cases of paranasal augmentation revealed an overall increase of soft tissue thickness of approximately 82.1% in 6-months following. 4. The successful results could be obtained under the aseptic handling.