• 대한치과보철학회지
• /
• 제56권1호
• /
• pp.70-76
• /
• 2018

과도한 치아 마모는 수직 고경 감소를 초래하고 구강 환경과 저작계의 병적 변화를 유발할 수 있다. 수직 고경과 교합을 회복시켜주기 위해서는 정확한 진단과 분석이 필수적이다. 본 증례에서는, 75세 여성환자로 구치부 지지 상실로 인한 치아 심한 마모가 관찰되었다. 따라서 수직 고경 거상을 동반한 전악 재건 수복을 계획하였다. 정확한 임상적 방사선학적 검사, 수직 고경 평가 후 진단 납형을 제작하였고 임시보철수복을 통해 환자의 적응여부를 평가하였다. 최종 수복은 환자의 경제적 상황을 고려하여 가철성 국소의치를 제작하였으며 하악 좌우측 구치부에 임플란트를 한 개씩 식립하여 국소의치의 지지와 유지를 보강하였다. 최종 수복물 장착 후 1년 간의 경과관찰 기간 동안 기능적, 심미적으로 만족할 만한 결과를 보였다.

• 구강회복응용과학지
• /
• 제33권2호
• /
• pp.135-142
• /
• 2017

컴퓨터를 이용한 CAD/CAM milling 방식이 치과 분야에도 적용됨에 따라 보다 분석적이고 정밀한 보철물이 제작 가능하게 되었다. 특히, 국소의치의 지대치로 사용되는 서베이드 크라운을 제작하는데 있어 이러한 디지털 방식의 정밀함은 국소의치의 삽입철거로와 언더컷 등이 정확하게 부여될 수 있게 한다. 본 증례는 상악의 다수 치아 상실을 보이는 환자에서 CAD/CAM을 이용하여 전자 서베잉을 통해 적절한 삽입철거로를 부여하고 지르코니아 서베이드 크라운을 제작하였다. 국소의치의 적합도는 우수했으며, 장착 후 안정성과 착탈 시의 유지력 또한 임상에서 적용하는 데에 문제가 없었다.

• 대한치과보철학회지
• /
• 제40권5호
• /
• pp.429-440
• /
• 2002

Current dental restorations present a relatively weak resistance to fracture. Owing to their unique mechanical properties, fibre-reinforced polymers are now being considered. Unidirectional or woven continuous fibres, made of glass, polyethylene, carbon or Kevlar, have been evaluated. This study focused on the use of glass fibre knitted fabrics to reinforce acrylate resins, in order to investigate the possibility to construct single crowns as well as three unit bridges. Some points affecting the final composite system were tested ; 1) static strength, with focus on the stress transfer under a occlusal contact point ; 2) modelling of a three nit bridge ; 3) fatigue strength as a posterior three unit bridge material. The study demonstrated that knitted fabric reinforcements are showing an interesting compromise between stiffness, static strength for single crown. For three unit bridge applications in the posterior arch, however knitted glass fabric reinforcements were not strong enough in fatigue An additional reinforcement in the posterior arch fixed partial denture design was recommended.

• 구강회복응용과학지
• /
• 제22권4호
• /
• pp.301-307
• /
• 2006

The subgingival fracture near the alveolar bone is difficult to treat. This fractured tooth will be treated by many methods. First approach is to preserve the fractured tooth. Periodontal surgery has been used to lengthen the clinical crown, thereby allowing the tooth to be restored. Another method is erupting the tooth with orthodontic eruption (forced eruption) or surgical extrusion. Second approach is the restoration after extraction of the subgingivally fractured tooth. This is restorative with conventional fixed partial denture or implant. This article presents the variable restorative approach of subgingivally fractured upper incisor.

• Archives of Reconstructive Microsurgery
• /
• 제8권1호
• /
• pp.1-9
• /
• 1999

Surgical treatment was performed on the 39 cases out of 76 cases of entrapments of the thoracic outlet. The remaining 36 cases of entrapments were treated by conservatively. The operated cases were categorized as follows. They were 34 cases of scalenus anticus syndrome, 1 of cervical rib syndrome, 2 of costoclavicular syndrome, and 2 of hyperabduction syndrome. 1. Scalenus anticus syndrome : Anterior scalenotomy was performed by simple sectioning of the attachment to the first rib. 2. Cervical rib syndrome : Complete decompressive resection of cervical rib sometimes required both anterior and posterior approaches to avoid over-retraction of the brachial plexus. 3. Costoclavicular syndrome : Partial decompressive claviculectomy was undergone instead of conventional total claviculectomy. 4. Hyperabduction syndrome : The resection of coracoid process was performed as well as conventional tenotomy of pectoralis minor muscle to insure free up-and-down moving of neurovascular bundle at the time of hyperabduction. Every diagnostic maneuver was tested at the time of operation to observe whether or not neurovascular decompression including restoration of radial pulse was sufficient. Despite of the postoperative vascular restoration was inmediate, neurogenic symptoms were improved slowly. Because this entity is essentially chronic nerve injnry, its recovery needed a couple of months or several. Although improvement was slow, ultimate results were definite. Complication was not observed.

• 한국컴퓨터정보학회논문지
• /
• 제3권2호
• /
• pp.139-146
• /
• 1998

비촛점흐려짐과 가산잡음에 의해 훼손된 영상을 정칙화 공액경사법을 이용하여 복원하는 방법을 제안하였다. 기존의 반복복원방법에 비하여 공액경사법은 초선형적인 수렴속도로 해에 수렴할 뿐 아니라 한정된 반복 횟수 내에 원래의 해에 수렴할 수 있다는 장점을지닌다. 본 논문은 반복복원시 잡음의 증폭을 억제하기 위하여 정칙화 공액 경사법에 구속조건을 적용함으로써 적응적으로 윤곽부분과 평면부분의 복원을 행하는 정칙화 공액경사법을 제안하였다. 제안한 방법은 기존의 방법에 비해, 윤곽부분에서는 1에 근사한 구속조건의값을 적용함으로서 윤곽의 복원을 행하고, 평면부분에서는 0에 근사하는 구속조건을 정칙화 공액경사법에 적용함으로써 잡음을 증폭을 억제할 수 있다는 장점을 지닌다.

• 구강회복응용과학지
• /
• 제23권2호
• /
• pp.145-155
• /
• 2007

The advent of osseointegration and advances in biomaterials and techniques have contributed to increased application of dental implants in the restoration of maxillary partial edentulous patients. Often, in these patients, soft and hard tissue defects result from a variety of causes, such as infection, trauma, and tooth loss. These create an anatomically less favorable foundation for ideal implant placement. Reconstruction of the atrophic maxillary alveolar bone through a variety of regenerative surgical procedures has become predictable; it may be necessary prior to implant placement or simultaneously at the time of implant surgery to provide a restoration with a good long-term prognosis. Regenerative procedures are used for horizontal and vertical ridge augmentation. Many different techniques exist for effective bone augmentation. The approach is largely dependent on the extent of the defect and specific procedures to be performed for the implant reconstruction. It is most appropriate to use an evidenced-based approach when a treatment plan is being developed for bone augmentation cases. The cases presented in this article clinically demonstrate the efficacy of using a autogenous block graft, guided bone regeneration, ridge split, immediated implant placement technique on the atrophic maxillary area.

• Restorative Dentistry and Endodontics
• /
• 제39권3호
• /
• pp.220-225
• /
• 2014

A fiber-reinforced composite (FRC) fixed prosthesis is an innovative alternative to a traditional metal restoration, as it is a conservative treatment method. This case report demonstrates a detailed procedure for restoring a missing anterior tooth with an FRC. A 44-year-old woman visited our department with an avulsed tooth that had fallen out on the previous day and was completely dry. This tooth was replanted, but it failed after one year. A semi-direct technique was used to fabricate a FRC fixed partial prosthesis for its replacement. The FRC framework and the pontic were fabricated using a duplicated cast model and nanofilled composite resin. Later on, interproximal contact, tooth shape, and shade were adjusted at chairside. This technique not only enables the clinician to replace a missing tooth immediately after extraction for minimizing esthetic problems, but it also decreases both tooth reduction and cost.

• 대한원격탐사학회지
• /
• 제38권1호
• /
• pp.33-43
• /
• 2022

This study presents a method to restore an optical satellite image with distortion and occlusion due to fog, haze, and clouds to one that minimizes degradation factors by referring to the same type of peripheral image. Specifically, the time and cost of re-photographing were reduced by partially occluding a region. To maintain the original image's pixel value as much as possible and to maintain restored and unrestored area continuity, a simulation restoration technique modified with the Cycle Generative Adversarial Network (CycleGAN) method was developed. The accuracy of the simulated image was analyzed by comparing CycleGAN and histogram matching, as well as the pixel value distribution, with the original image. The results show that for Site 1 (out of three sites), the root mean square error and R² of CycleGAN were 169.36 and 0.9917, respectively, showing lower errors than those for histogram matching (170.43 and 0.9896, respectively). Further, comparison of the mean and standard deviation values of images simulated by CycleGAN and histogram matching with the ground truth pixel values confirmed the CycleGAN methodology as being closer to the ground truth value. Even for the histogram distribution of the simulated images, CycleGAN was closer to the ground truth than histogram matching.

• 한국컴퓨터정보학회논문지
• /
• 제28권3호
• /
• pp.59-65
• /
• 2023

다양한 분야에서 블록체인을 적용한 연구가 활발하게 증가함에 따라 블록체인의 사용자를 증명하는 개인키의 관리가 중요하게 되었다. 개인키를 분실하게 되면 본인의 모든 데이터에 대한 권한을 잃게 된다. 이에 대한 문제점을 해결하고자 기존에는 블록체인 지갑, 부분 정보를 이용한 개인키 복구, 분산 저장을 통한 개인키의 복구 등을 제안하였다. 본 논문에서는 Shamir's Secrete Sharing(SSS) 스킴과 생체정보를 이용하여 안전한 개인키의 백업 및 복구 방안을 제안하고 이에 대한 안전성을 메시지 교환시의 견고성, 재생공격, 중간자 공격 및 위변조 공격에 대해 평가한다.