• Journal of Korean Dental Science
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• 제15권1호
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• pp.84-91
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• 2022

An all-on-4 restoration allows edentulous patients to use a fixed prosthesis with a minimum number of implants. These implant-supported fixed complete dentures have traditionally been fabricated as screw-retained or cement-retained prostheses. However, it is difficult to passively fit the long-span full-arch prosthesis using the screw-retained type restoration, and predictable retrievability is not obtained with the cement-retained type. This case report describes a prosthesis fabricated using a combination of the two retention types. The screwmentable method allows the implant-supported fixed complete denture to achieve a passive fit at the connection with retrievability. In addition, a framework with an optimized size was designed by using digital dental technology.

• Geomechanics and Engineering
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• 제20권6호
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• pp.485-495
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• 2020

Based on the movement characteristics of overlying strata with gangue backfilling, the compression test of gangue is designed. The deformation characterristics of gangue is obtained based on the different Talbot index. The deformation has a logarithmic growth trend, including sharp deformation stage, linear deformation stage, rheological stage, and the resistance to deformation changes in different stages. The more advantageous Talbot gradation index is obtained to control the surface subsidence. On the basis of similarity simulation test with gangue backfilling, the characteristics of roof failure and the evolution of the supporting force are analyzed. In the early stage of gangue backfilling, beam structure damage directly occurs at the roof, and the layer is separated from the overlying rock. As the working face advances, the crack arch of the basic roof is generated, and the separation layer is closed. Due to the supporting effect of filling gangue, the stress concentration in gangue backfilling stope is relatively mild. Based on the equivalent mining height model of gangue backfilling stope, the relationship between full ratio and mining height is obtained. It is necessary to ensure that the gradation of filling gangue meets the Talbot distribution of n=0.5, and the full ratio meets the protection grade requirements of surface buildings.

• 대한치과기공학회지
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• 제34권2호
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• pp.121-128
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• 2012

Purpose: The aim of this study was to determine the reliability and accuracy of measurements in digital models(CEREC$^{(R)}$ AC) compared to stone models. Methods: A master model(500B-1, Nissin Dental Product, Japan) with the prepared upper full arch tooth was used. Conventional impression and then stone model(n=10) were produced from this master model, and on the other hands, digital impressions were made with the CEREC$^{(R)}$ AC intra-oral scanner(n=10). One examiner measured two times the intercanine, intermolar distance, dental arch length. The stone model were measured using a digital caliper. The t-student test for paired samples and intraclass correlation coefficient(ICC) were used for statistical analysis. Results: The measurement of two methods showed very good reliability. At the intra-examiner reliability of measurement, ICC at the stone and CEREC$^{(R)}$ AC model were 0.81 and 0.94. The mean difference between measurements made directly on the stone models and those made on the CEREC$^{(R)}$ AC model was 0.20~0.28mm, and was statistically significant(P=0.001). Conclusion: These in vitro studies show that accuracy of the digital impression is similar to that of the conventional impression. These results will have to be confirmed in further clinical studies.

• 구강회복응용과학지
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• 제30권4호
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• pp.339-349
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• 2014

상악과 하악의 크기부조화가 있거나 악간관계가 불안정한 환자의 치료목적은 안정적인 교합접촉을 부여하는 것이다. 중등도의 정신지체 환자로 부족한 수직고경, 수평적 악골관계 부조화, 광범위한 치질소실로 인하여 보철치료가 필요하였다. 두부계측학적 평균치를 기준으로 악골위치를 판별하고, 연조직 측모분석 후 수평 골삭제량을 결정하였다. 수술 부위의 안정적인 치유 및 설정된 상하악관계에 대한 의치 적응여부를 평가하였다. 만족할만한 심미성과 안정적 교합상태를 얻었으나, 추가적인 교합변화의 가능성을 고려한 정기적인 관리가 필요할 것으로 사료된다.

• 한국운동역학회지
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• 제17권3호
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• pp.81-94
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• 2007

The purpose of this study was to critically review biomechanical studies on foot orthoses (FO) in normal and diseased foot and provide beneficial information obtained from researches until now and future researching focus. The search was performed by Medline and Embase database including studies published in English from January 1980 to April 2007. The searching terms were foot orthoses, foot orthotics, insoles and shoe insert. 57 studies including 54 journal articles and 3 abstracts were finally selected under the conditions of having clinical trials, FO, control condition, movement, scientific measuring system. The reviewed studies were divided into 10 categories according to subject characteristics; healthy normal, excessive pronation or flexible flat foot, rheumatoid arthritis, diabetes, medial knee osteoarthritis, forefoot varus, plantar fasciitis, patellofemoral syndrome, cavus foot and finite element model. In summary, first, soft and semirigid FOs with some degree of cushioning showed much higher comfort and efficacy than rigid FO. Second, no big differences between prefabricated and custom FO were shown. Third, the full length's FO was preferable to the half length's FO or simple arch supports. Fourth, the wearing of FO combining medial arch supports and metatarsal dome made positive roles to enhance comfort and functionality and redistribute plantar pressure under the foot. Fifth, for patients with knee-related diseases lateral wedges were preferable. Sixth, measuring systems were properly applied according to the types of foot diseases.

• 대한심미치과학회지
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• 제27권2호
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• pp.82-96
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• 2018

3D 프린팅은 삼차원 이미지 정보를 이용하여 레이어로 분할한 후 선택한 소재를 적층하여 가공하는 방법을 말한다. 소재를 적층하는 방법에 따라 다양한 종류의 3D 프린팅이 존재하는데 최근 치과분야에서는 SLA방식과 DLP방식으로 광원을 이용한 경화를 통해 적층 가공하는 3D 프린팅이 널리 보급되어 사용되고 있다. 전악 범위의 3D프린팅 치과용 모델은 전통적인 인상 채득으로 제작된 스톤모델보다는 다소 정확성이 부족한 것으로 보고되었으나, 같은 STL파일을 이용하여 4분악 범위를 3D 프린팅한 모델은 밀링 방법으로 가공한 모델보다 정확하였다. 디자인 소프트웨어의 활용도에 따라 보철치료의 진단, 임시 보철물의 제작, 의치의 제작이 가능하였다. 교정에서는 투명 교정 모델과 브라켓 간접 부착을 위한 트레이 제작이 가능하였다. 임플란트 수술에 있어서 CT를 기반으로 한 정확한 위치에 임플란트를 식립하는 가이드 제작에 활용하고 있다. 출력 방식의 발전으로 인하여 3D 프린터의 출력시간이 계속적으로 단축되고 있으며, 이로 인해 치과 진료실 내에서 3D 프린터가 기존의 전통적인 가공 방법을 대체할 수 있을 것으로 기대한다.

• Korean Journal of Radiology
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• 제22권5호
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• pp.829-839
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• 2021

Objective: To compare the diagnostic performance of contrast-enhanced radial T1-weighted gradient-echo 3-tesla (3T) magnetic resonance imaging (MRI) and computed tomography (CT) for the detection of visceral pleural surface invasion (VPSI). Visceral pleural invasion by non-small-cell lung cancer (NSCLC) can be classified into two types: PL1 (without VPSI), invasion of the elastic layer of the visceral pleura without reaching the visceral pleural surface, and PL2 (with VPSI), full invasion of the visceral pleura. Materials and Methods: Thirty-three patients with pathologically confirmed VPSI by NSCLC were retrospectively reviewed. Multidetector CT and contrast-enhanced 3T MRI with a free-breathing radial three-dimensional fat-suppressed volumetric interpolated breath-hold examination (VIBE) pulse sequence were compared in terms of the length of contact, angle of mass margin, and arch distance-to-maximum tumor diameter ratio. Supplemental evaluation of the tumor-pleura interface (smooth versus irregular) could only be performed with MRI (not discernible on CT). Results: At the tumor-pleura interface, radial VIBE MRI revealed a smooth margin in 20 of 21 patients without VPSI and an irregular margin in 10 of 12 patients with VPSI, yielding an accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and F-score for VPSI detection of 91%, 83%, 95%, 91%, 91%, and 87%, respectively. The McNemar test and receiver operating characteristics curve analysis revealed no significant differences between the diagnostic accuracies of CT and MRI for evaluating the contact length, angle of mass margin, or arch distance-to-maximum tumor diameter ratio as predictors of VPSI. Conclusion: The diagnostic performance of contrast-enhanced radial T1-weighted gradient-echo 3T MRI and CT were equal in terms of the contact length, angle of mass margin, and arch distance-to-maximum tumor diameter ratio. The advantage of MRI is its clear depiction of the tumor-pleura interface margin, facilitating VPSI detection.

• 대한치과보철학회지
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• 제56권1호
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• pp.88-94
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• 2018

최근 치과치료의 영역에서 디지털 임플란트 시스템은 그 영역을 넓혀 나가고 있다. 디지털 장비들의 기술적 발전에 힘입어 한계점들이 하나 둘씩 극복되었다. 초기 단일치아 수복 정도에나 사용되었던 디지털 임플란트 시스템은 임플란트 수술에서부터 보철물 제작까지 무치악의 영역에서도 사용되고 있다. 본 증례에서는 50세의 하악 무치악 환자가 임플란트를 이용한 교합 재건을 원하였다. 하악의 임플란트 수복을 위해서 "All-on-4" 개념의 디지털 임플란트 시스템 사용을 계획하였고, 무절개 수술을 위한 가이드 장치를 제작하여 수술을 시행하였다. 수술 후, 전악 보철을 디지털 장비를 이용하여 제작하였다. 전체 치료 과정에서 기존의 아날로그 방식(인상채득, 납형 제작, 주조 등)을 가능한 배제하고 디지털 시스템을 이용하여 기공과정 및 임상과정을 최소화하기로 계획하였고 만족할만한 결과를 얻었기에 보고하는 바이다.

• Archives of Plastic Surgery
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• 제34권3호
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• pp.325-329
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• 2007

Purpose: Mobius syndrome is a rare congenital disorder characterized by facial diplegia and bilateral abducens palsy, which occasionally combines with other cranial nerve dysfunction. The inability to show happiness, sadness or anger by facial expression frequently results in social dysfunction. The classic concept of cross facial nerve grafting and free muscle transplantation, which is standard in unilateral developmental facial palsy, cannot be used in these patients without special consideration. Our experience in the treatment of three patients with this syndrome using transfer of muscles innervated by trigeminal nerve showed rewarding results. Methods: We used bilateral temporalis muscle elevated from the bony temporal fossa. Muscles and their attached fascia were folded down over the anterior surface of the zygomatic arch. The divided strips from the attached fascia were passed subcutaneously and anchored to the medial canthus and the nasolabial crease for smiling and competence of mouth and eyelids. For the recent 13 years the authors applied this method in 3 Mobius syndrome cases- 45 year-old man and 13 year-old boy, 8 year-old girl. Results: One month after the surgery the patients had good support and already showed voluntary movement at the corner of their mouth. They showed full closure of both eyelids. There was no scleral showing during eyelid closure. Also full closure of the mouth was achieved. After six months, the reconstructed movements of face were maintained. Conclusion: Temporalis muscle transfer for Mobius syndrome is an excellent method for bilateral reconstruction at one stage, is easy to perform, and has a wide range of reconstruction and reproducibility.

• 구강회복응용과학지
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• 제30권1호
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• pp.71-80
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• 2014

골흡수가 심한 환자에서 임플란트를 이용한 전악 수복의 경우 치은과 치아의 외형을 심미적이면서도 기능적으로 회복하기 위해서는 보철물 제작에 있어 신중을 기해야 한다. 이러한 전악 수복 증례에서 CAD/CAM 시스템이 높은 정확성을 가지는 보철물 제작을 가능하게 함으로써 사용이 증가하고 있다. 최근에 임상에서 티타늄이나 지르코니아의 단점을 보완하면서 높은 생체적합성을 가지고 CAD/CAM 시스템으로 제작할 수 있는 팔라듐-은(Pd-Ag) 합금이 개발되어 사용되고 있다. 본 증례에서는 상악 전부 무치악 환자에서 임플란트를 식립하고 도재의 chipping이나 파절의 위험을 감소시키기 위해 Pd-Ag 합금을 이용해 제작된 임플란트 고정성 보철물로 수복한 환자에 대해 보고하고자 한다.