• Journal of International Society for Simulation Surgery
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• 제1권1호
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• pp.13-15
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• 2014

Nowadays, with advanced 3D printing techniques, the custom-made implant can be manufactured for the patient. Especially in skull reconstruction, it is difficult to design the implant due to complicated geometry. In large defect, an autograft is inappropriate to cover the defect due to donor morbidity. We present the process of manufacturing the 3D custom-made implant for skull reconstruction. There was one patient with skull defect repaired using custom-made 3D titanium implant in the plastic and reconstructive surgery department. The patient had defect of the left parieto-temporal area after craniectomy due to traumatic subdural hematoma. Custom-made 3D titanium implants were manufactured by Medyssey Co., Ltd. using 3D CT data, Mimics software and an EBM (Electron Beam Melting) machine. The engineer and surgeon reviewed several different designs and simulated a mock surgery on 3D skull model. During the operation, the custom-made implant was fit to the defect properly without dead space. The operative site healed without any specific complications. In skull reconstruction, autograft has been the treatment of choice. However, it is not always available and depends on the size of defect and donor morbidity. As 3D printing technique has been advanced, it is useful to manufacture custom-made implant for skull reconstruction.

• 한국CDE학회논문집
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• 제13권3호
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• pp.200-208
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• 2008

Total Hip Replacement(THR) is a surgical procedure that replaces a diseased hip joint with a prosthesis. A plastic or metal cup forms the socket, and the head of the femur is replaced by a metal ball on a stem placed inside the femur. Due to the various types and shapes of human hip joint of every individual, a selected commercial implant sometimes may not be the best-fit to a patient, or it cannot be applied because of its discrepancy. Hence extracting geometry parameters of hip joint is one of the most crucial processes in designing custom-made implants. This paper describes the framework of a methodology to extract the geometric parameters of the hip joint. The parameters include anatomical axis, femoral head, head offset length, femoral neck, neck shaft angle, anteversion, acetabulum, and canal flare index. The proposed system automatically recommends the size and shape of a custom-made hip implant with respect to the patient's individual anatomy from 3D models of hip structures. The proposed procedure creating these custom-made implants with some typical examples is precisely presented and discussed in this paper.

• 대한의용생체공학회:의공학회지
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• 제27권6호
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• pp.402-408
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• 2006

The choice of suitable hip implant is one of important factors in the total hip arthroplasty (THA). In clinical view point, an improper adaptation of hip implant might induce abnormal stress distribution to the bone, which can shorten the lifespan of replaced hip implant. Currently, interest in the custom-designed hip implants has increased as studies reveal the significance of geometric shape of patient's femur in modeling and designing the implants. In this study, we have developed custom-designed hip implant models with various sizes, and analyzed the stress distribution in the bone and bone cement using the Finite Element Method. It was found that minimizing the gap between implant stem and femoral cavity is crucial to minimize the stress concentration in the bone.

• 대한치과보철학회지
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• 제51권4호
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• pp.276-283
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• 2013

연구 목적: 본 연구에서는 기성 지대주와 맞춤형CAD-CAM 지대주의 적합성 및 나사 사이의 안정성 대해 알아보고자 한다. 연구 재료 및 방법: 오스템 임플란트 시스템을 이용하였다. 동일회사에서 제작된 기성 지대주(Transfer abutment, Osstem Implant Co. Ltd, Busan, Korea) 및 맞춤형CAD-CAM 지대주(CustomFit abutment, Osstem Implant Co. Ltd, Busan, Korea)와 국내 외주 제작된 맞춤형CAD-CAM 지대주(Myplant, Raphabio Co., Seoul, Korea)를 5개씩 선택, 제작하였으며 나사는 각 회사에서 제공되는 것을 사용하였다. 제조사의 지시에 따라 고정체와 지대주를 30 Ncm으로 조인 후 초기 풀림 토크를 3회 반복 측정한 후 통계 분석하였다(${\alpha}=.05$). 고정체-지대주 연결체를 에폭시 레진에 매몰 후 습식 절삭 및 연마하여 계면 사이의 적합성을 FE-SEM으로 관찰하였다. 결과: 지대주의 초기 풀림 토크 값은 각각 기성 지대주(Transfer abutment)에서 $26.0{\pm}0.30Ncm$, 동일 회사에서 제작된 맞춤형CAD-CAM 지대주(CustomFit abutment)에서 $26.3{\pm}0.32Ncm$, 외주로 제작된 맞춤형CAD-CAM 지대주(Myplant abutment)에서 $24.7{\pm}0.67Ncm$였다. 국내 외주 제작된 맞춤형CAD-CAM 지대주에서 유의적으로 낮은 초기 풀림 토크 값을 보였으며(P=.027), 고정체-지대주 계면에서 변연 간극이 관찰되었다. 결론: 본 실험의 한계 내에서 국내 외주 제작된 맞춤형CAD-CAM 지대주는 동일 회사에서 제작된 기성 지대주나 맞춤형CAD-CAM 지대주에 비해 더 낮은 나사 안정성 및 적합성을 보인다고 볼 수 있다.

• 대한두개안면성형외과학회지
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• 제19권2호
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• pp.135-138
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• 2018

Parry-Romberg syndrome is a rare neurocutaneous syndrome characterized by progressive shrinkage and degeneration of the tissues usually on only one side of the face. It is usually difficult to restore the facial contour due to skin tightness. In this case report, we report a forehead reconstruction with custom-made three-dimensional (3D) titanium implant of a Parry-Romberg syndrome patient who was treated with multiple fat grafts but had limited effect. A 36-year-old man presented with hemifacial atrophy. The disease progressed from 5 to 16 years old. The patient had alopecia on frontal scalp and received a surgery using tissue expander. The alopecia lesion was covered by expanded scalp flap done 22 years ago. Also, he was treated with fat grafts on depressed forehead 17 years ago. However, it did not work sufficiently, and there was noted depressed forehead. We planned to make 3D titanium implant to cover the depressed area (from the superior orbital rim to the vertex). During the operation, we confirmed that the custom-made 3D implant accurately fit for the depressed area without any dead spaces. Previously depressed forehead and glabella were elevated, and the forehead contour was improved cosmetically. A custom-made 3D titanium implant is widely used for skull reconstruction and bring good results. In our case, the depressed forehead of a Parry-Romberg syndrome patient was improved by a 3D titanium implant.

• 대한두개안면성형외과학회지
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• 제16권1호
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• pp.11-16
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• 2015

Background: Source material used to fill calvarial defects includes autologous bones and synthetic alternatives. While autologous bone is preferable to synthetic material, autologous reconstruction is not always feasible due to defect size, unacceptable donor-site morbidity, and other issues. Today, advanced three-dimensional (3D) printing techniques allow for fabrication of titanium implants customized to the exact need of individual patients with calvarial defects. In this report, we present three cases of calvarial reconstructions using 3D-printed porous titanium implants. Methods: From 2013 through 2014, three calvarial defects were repaired using custom-made 3D porous titanium implants. The defects were due either to traumatic subdural hematoma or to meningioma and were located in parieto-occipital, fronto-temporo-parietal, and parieto-temporal areas. The implants were prepared using individual 3D computed tomography (CT) data, Mimics software, and an electron beam melting machine. For each patient, several designs of the implant were evaluated against 3D-printed skull models. All three cases had a custom-made 3D porous titanium implant laid on the defect and rigid fixation was done with 8 mm screws. Results: The custom-made 3D implants fit each patient's skull defect precisely without any dead space. The operative site healed without any specific complications. Postoperative CTs revealed the implants to be in correct position. Conclusion: An autologous graft is not a feasible option in the reconstruction of large calvarial defects. Ideally, synthetic materials for calvarial reconstruction should be easily applicable, durable, and strong. In these aspects, a 3D titanium implant can be an optimal source material in calvarial reconstruction.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제37권
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• pp.1.1-1.6
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• 2015

The restoration of extensive zygomatic complex defects is a surgical challenge owing to the difficulty of accurately restoring the normal anatomy, symmetry, proper facial projection and facial width. In the present study, an extensive post-traumatic zygomatic bone defect was reconstructed using a custom-made implant that was made with a selective laser melting (SLM) technique. The computer-designed implant had the proper geometry and fit perfectly into the defect without requiring any intraoperative adjustments. A one-year follow-up revealed a stable outcome with no complications.

• 대한치과보철학회지
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• 제50권2호
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• pp.128-134
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• 2012

연구 목적: 본 연구는 국내 개발된 맞춤형 임플란트 지대주와 기성 임플란트 지대주의 반복 하중 전과 후의 나사 풀림 토크 값을 측정, 비교하여 나사 결합부 안전성에 차이가 있는지를 알아보고자 하였다. 연구 재료 및 방법: 총 12개의 임플란트 고정체(Implantium, Dentium Co., Seoul, Korea)를 알루미늄 원통에 레진으로 고정하고, 그것을 각각 4개씩, 3개의 군으로 나눠서 각 군별로 기성 티타늄 지대주(Implantium, Dentium Co., Seoul, Korea), 캐드캠 맞춤형 티타늄 지대주(Myplant, Raphabio Co., Seoul, Korea), 그리고 금속 연결부가 있는 캐드캠 맞춤형 지르코니아 지대주(Zirconia Myplant, Raphabio Co., Seoul, Korea)를 제작하여 임플란트에 연결하였다. 금속관은 지대주에 맞춰서 티타늄을 밀링해서 제작한뒤 지대주에 합착하였다. 반복 하중을 가하기 전에 지대주 나사를 30 Ncm 토크로 조이고 약 30분 후 나사의 초기 풀림 토크값을 측정하였다. 그 후 반복 하중을 30 N에서 120 N의 싸인 곡선을 이루는 압축력으로 2 Hz의 빈도로 50만 싸이클을 가하고 하중 후 풀림 토크값을 측정하였으며, 풀림 토크 상실률을 구하여서 군끼리 비교하였다. 나사의 풀림 토크값의 상실률의 비교를 위해 Kruskal-Wallis test를 이용해서 유의수준 .05에서 분석하였다. 결과: 반복하중 후 나사 풀림 상실률에서 기성 티타늄 지대주 군에 비해 맞춤형 티타늄 지대주는 높은 값을 보였으나 유의성 있는 차이를 보이지 않았다($P$>.05). 반면, 맞춤형 지르코니아 지대주는 기성 티타늄 지대주에 비해 유의하게 높은 값을 보였다($P$=.014). 결론: 본 실험의 한계 내에서 캐드캠 맞춤형 티타늄 임플란트 지대주는 기성 임플란트 지대주 에 비해 나사 안정성이 떨어진다고 볼 수 없다. 반면, 캐드캠 맞춤형 지르코니아 지대주 는 기성 임플란트 지대주에 비해 나사 안정성이 다소 떨어진다고 볼 수 있다.

• 한국CDE학회논문집
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• 제21권4호
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• pp.426-432
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• 2016

Designing a morphologically well-fitted hip implant to a patient anatomy is desirable to improve surgical outcomes since a commercial ready-made hip implant may not well conform to the patient joint. In this study, biomechanical stability of patient-specific hip implants with two different stem lengths was compared and discussed using a 3D finite element analysis (FEA). The FEA results in this study showed that an increase in stem length brings about more the peaked von-Mises stress (PVMS) in the prosthesis and less in the femur. However the decrease in von-Mises stress in the femur causes stress shielding phenomenon that usually leads to considerable bone resorption. Although, in biomechanical stability point of view, this work recommends the use of smaller stems, the length of stem must be determined by considering both the von-Mises stress and the stress-shielding phenomenon.

• 대한치과보철학회지
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• 제54권4호
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• pp.370-378
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• 2016

목적: Biomet 3i 시스템과 Astra 시스템의 내측 연결형 임플란트 고정체에 국내에서 제작된 맞춤형 CAD-CAM 지대주를 체결하여 구성 성분 간의 적합성과 나사의 안정성을 평가하고자 하였다. 재료 및 방법: 24개 3i 임플란트 중 12개의 임플란트에 기성 지대주를 연결하고, 나머지 임플란트에는 맞춤형 CAD-CAM 지대주를 연결하여 각각 Group 1과 Group 2로 분류하였다. 동일 개수와 동일한 방법으로 Astra 임플란트를 각각 Group 3와 Group 4로 분류하였다. 각각의 고정체에 지대주를 장착하여 각 계면 사이의 적합성을 micro-CT로 관찰하고 초기 풀림 토크를 측정한 후 평가하였다. 결과: 고정체-지대주의 접촉길이는 Group 1과 Group 2 사이 뿐만 아니라 Group 3와 Group 4 사이에도 유의한 차이가 없었다(Mann-Whitney test, P>.05). 하지만, 지대주와 나사의 계면 및 고정체와 나사의 계면에서 Group 2와 Group 4가 Group 1와 Group 3에 비해 각기 더 큰 접촉양상을 보여주었다(Mann-Whitney test, P<.05). 또한, Group 2와 Group 4가 Group 1과 Group 3에 비해 각기 더 낮은 나사의 초기 풀림 토크를 기록하였다(Student t-test, P<.05). 결론: CAD-CAM지대주는 임상에 적용할 만한 적합성을 지니고 있으나, 광범위한 임상 적용을 위해서는 풀림 토크가 향상되어야 할 것으로 사료된다.