• Maxillofacial Plastic and Reconstructive Surgery
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• 제38권
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• pp.50.1-50.6
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• 2016

Background: The aim of this study was to evaluate the clinical outcomes of implants that were placed within the maxillary sinus that has a perforated sinus membrane by the lateral window approach. Methods: We examined the medical records of the patients who had implants placed within the maxillary sinus that has a perforated sinus membrane by the lateral approach at the Department of Oral and Maxillofacial Surgery of Chonnam National University Dental Hospital from January 2009 to December 2015. There were 41 patients (male:female = 28:13). The mean age of patients was $57.2{\pm}7.2years$ at the time of operation (range, 20-76 years). The mean follow-up duration was 2.1 years (range, 0.5-5 years) after implant placement. Regarding the method of sinus elevation, only the lateral approach was included in this study. Results: Ninety-nine implants were placed in 41 patients whose sinus membranes were perforated during lateral approach. The perforated sinus membranes were repaired with a resorbable collagen membrane. Simultaneous implant placements with sinus bone grafting were performed in 37 patients, whereas delayed placements were done in four patients. The average residual bone height was $3.4{\pm}2.0mm$ in cases of simultaneous implant placement and $0.6{\pm}0.9mm$ in cases of delayed placement. Maxillary bone graft with implant placement, performed on the patients with a perforated maxillary sinus membrane did not fail, and the cumulative implant survival rate was 100%. Conclusions: In patients with perforations of the sinus mucosa, sinus elevation and implant placement are possible regardless of the location and size of membrane perforation. Repair using resorbable collagen membrane is a predictable and reliable technique.

• 대한치과의사협회지
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• 제57권3호
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• pp.149-160
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• 2019

Atrophic alveolar ridge of maxillary anterior area is commonly observed after the extraction of teeth in patients with severely compromised periodontal disease, causing difficulties with implant placement. Successful esthetics and functional implant rehabilitation rely on sufficient bone volume, adequate bone contours, and ideal implant positioning and angulation. The present case report categorized the ridge augmentation techniques using guided bone regeneration (GBR) on the maxillary anterior site by Seibert classification. Case I patient presented for implant placement in the position of tooth #11. The alveolar ridge was considered a Seibert classification I ridge defect. Simultaneous implant placement and GBR were performed. Eight months after implantation, clinical and radiological examinations were performed. Case III patient presented with discomfort due to mobility of the upper maxillary anterior site. Due to severe destruction of alveolar bone, teeth #11 and #12 were extracted. After three months, the alveolar ridge was considered a Seibert classification III ridge defect. A GBR procedure was performed; implantation was performed 6 months later. Approximately 1-year after implantation, clinical and radiological examinations were performed. During the whole treatment period, healing was uneventful without membrane exposure, severe swelling, or infection in all cases. Radiographic and clinical examinations revealed that atrophic hard tissues and buccal bone contour were restored to the acceptable levels for implant placement and esthetic restoration. In conclusion, severely resorbed alveolar ridge of the maxillary anterior area can be reconstructed with ridge augmentation using the GBR procedure so that dental implants could be successfully placed.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권3호
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• pp.249-255
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• 2011

Purpose: Placement of endosseous implants in the atrophic maxilla is often restricted because of the lack of supporting bone. In this article, augmentation of the maxillary sinus floor with deproteinized bovine bone to enable insertion of endosseous implants is described. The technique is aimed at providing a cortical layer on top of the graft to ensure a reliable seal of the maxillary sinus and to achieve optimal stability of the bone graft in case of simultaneously placement of dental implants. Methods: The procedure was used in 200 patients (839 implants), using deproteinized bovine bone. The mean follow-up was 28.5 months. No inflammation of the bone grafts nor of the maxillary sinus occurred. The patients received implant supported overdentures or bone-anchored bridges. Results: The survival rate of implant restoration of this study was 97.6%. The total average of marginal bone loss in radiographs was $0.20{\pm}0.38$ mm. Insufficient primary stability, bony quality, and infection were thought to be associated factors in the failed cases. Conclusion: This study documented that deproteinized bovine bone, when used as a grafting material for augmentation of the sinus floor, may lead to proper osseointegration of a endosseous implant.

• Communications for Statistical Applications and Methods
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• 제19권1호
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• pp.33-45
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• 2012

신약 개발 연구 또는 임상시험에서 개발된 약이 0용량 대조군과 비교해 효과 차이가 있는 가장 작은 용량을 최소 효과 용량(MED)이라 한다. 본 논문에서는 다중 그룹 상황에서 동시적(simultaneous)으로 각 각 그룹의 최소 효과 용량을 확인하기 위하여 위치(placement)에 기초한 비모수적 방법을 제시하였다. 또한 Monte Carlo 모의실험을 통하여 기존에 제시된 검정법과 본 논문에서 제안한 검정법의 검정력(power)과 FWE(Family-wise Error Rate)를비교하였다.

• Journal of Electrical Engineering and Technology
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• 제10권2호
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• pp.474-486
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• 2015

This paper proposes a multi-objective optimal placement method of Phasor Measurement Units (PMUs) in large electric transmission systems. It is proposed for minimizing the number of PMUs for complete system observability and maximizing measurement redundancy of the buses, simultaneously. The measurement redundancy of the bus indicates that number of times a bus is able to monitor more than once by PMUs set. A high level of measurement redundancy can maximize the system observability and it is required for a reliable power system state estimation. Therefore, simultaneous optimizations of the two conflicting objectives are performed using a binary coded firefly algorithm. The complete observability of the power system is first prepared and then, single line loss contingency condition is added to the main model. The practical measurement limitation of PMUs is also considered. The efficiency of the proposed method is validated on IEEE 14, 30, 57 and 118 bus test systems and a real and large- scale Polish 2383 bus system. The valuable approach of firefly algorithm is demonstrated in finding the optimal number of PMUs and their locations by comparing its performance with earlier works.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권3호
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• pp.117-122
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• 2014

Objectives: The purpose of this study was to evaluate the sinus bone graft resorption over 3 years after two-stage implant placement. Materials and Methods: The subjects for this study included 30 patients whose maxillary posterior ridges were too atrophic for implants. Bone-added osteotome sinus floor elevation was used in 15 maxillary sinuses, while the bone graft by lateral approach technique was used in 25 maxillary sinuses. The height from the top of the fixture to the sinus floor was estimated immediately after implant placement and the follow-up period was over 3 years. The surgery was classified with two groups: sinus bone grafting with and without autogenous bone. All implants were placed simultaneously. Results: The mean vertical bone loss was $3.15{\pm}2.95mm$. The survival rate of implants was 94.7%. Conclusion: The amount of bone resorption was not significantly associated with the surgical methods, the type of bone graft materials used, or sinus perforation during surgery.

• Clinical Endoscopy
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• 제56권2호
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• pp.135-142
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• 2023

Endoscopic biliary drainage strategies for managing unresectable malignant hilar biliary obstruction differ in terms of stent type, drainage area, and deployment method. However, the optimal endoscopic drainage strategy remains unclear. Uncovered self-expandable metal stents (SEMS) are the preferred type because of their higher functional success rate, longer time to recurrent biliary obstruction (RBO), and fewer cases of reintervention than plastic stents (PS). Other PS subtypes and covered SEMS, which feature a longer time to RBO than PS, can be removed during reintervention for RBO. Bilateral SEMS placement is associated with a longer time to RBO and a longer survival time than unilateral SEMS placement. Unilateral drainage is acceptable if a drainage volume of greater than 50% of the total liver volume can be achieved. In terms of deployment method, no differences were observed in clinical outcomes between side-by-side (SBS) and stent-in-stent deployment. Simultaneous SBS boasts a shorter procedure time and higher technical success rate than sequential SBS. This review of previous studies aimed to clarify the optimal endoscopic biliary drainage strategy for unresectable malignant hilar biliary obstruction.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제18권2호
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• pp.236-244
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• 1996

The maxillary sinus elevation for simultaneous placement of dental implants and combination grafts of autogenous bone harvested from the maxillary tuberosity and demineralized freeze dried bone and HA is relatively easy and safely done under local anesthesia in out patients clinic. This article is to introduce the sinus floor elevation method which has been performed to 5 patients in the department of Dentistry/Oral & Maxillofacial Surgery, Kangnam Sacred Heart Hospital, Hallym University, from 1993.

• 대한치과의사협회지
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• 제39권12호통권391호
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• pp.996-1005
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• 2001

• Archives of Plastic Surgery
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• 제49권5호
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• pp.652-655
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• 2022

Patients with advanced malignant tumors, including both jaws, is a challenging task for a head and neck surgeon. Current treatment landscape demonstrates good functional, anatomical, and aesthetic results in patients who could previously receive only palliative care. The extensive tissue defects resulting from oncological resections in the head and neck region require immediate reconstruction due to the exposure of vital structures and their contact with the external environment. A patient was operated using a three-team multidisciplinary approach involving simultaneous work of three specialized teams of maxillofacial and reconstructive microsurgeons, as well as an implantologist and a prosthodontist. This approach allowed simultaneous tumor resection with subsequent reconstruction of the intraoperative defect involving bilateral harvesting of two revascularized free fibular osteomusculocutaneous flaps with dental implantation and simultaneous rehabilitation of dentition with crowns.