• 대한치과교정학회지
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• 제25권1호
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• pp.73-85
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• 1995

교정치료시 치축의 개선을 위한 많은 연구와 노력이 이루어져 왔다. 본 교실에서는 치축개선을 위해 MEAW를 응용한 Multi-Vertical Loop Arch Wire(MVLAW : 엠빌로)를 수년 전부터 다수치아의 치축을 동시에 개선코자 사용해 왔다. MVLAW는 일종의 근심경사된 치아를 세우는 장치로써 open vertical loop를 3가지 종류로 변형시켜 적용시켜 왔으며 이를 각각 A, B, C형으로 명명하였다. 각 MVLAW는 .017"x.025" TMAwire로 제작되며, A형 MVLAW의 경우 각 open vertical loop의 apex를 10도 정도 벌려주어 활성화시키며(electric welding stop을 각 loop의 근심측에 위치시킨다), B형과 C형 MVLAW의 경우 open vertical loop의 원심측에 10도의 tip back bend를 형성함으로써 활성화시킨다(B형의 경우 electric welding stop이 각 loop의 원심측에 형성되는 반면 C형의 경우 electric welding stop을 형성하지 않는다). 본 연구는 구치부의 치축을 동시에 개선코자할 때 MVLAW를 3가지 종류로 분류한 후 각 MVLAW의 효과를 알아보고자 상하악 1/2악을 광탄성 모형에 재현하여 그 응력분포를 관찰하여 다음과 같은 결론을 얻었기에 보고하는 바이다. 1. A형 MVLAW의 경우 3급 견인고무를 걸지 않았을 경우 하악 제1대구치와 제2대구치 치근의 원심면에서 강한 응력분포를 나타내나 전치부에 발생한 미약한 응력분포는 3급 견인고무의 장착으로 상쇄되었다. 따라서 A형 MVLAW는 초기에 치관의 직립효과가 있는 것으로 보인다. 2. B형 MVLAW의 경우 3급 견인고무를 걸지 않았을 경우 각 치아의 근심측에 응력분포를 보이며 견인고무를 걸었을 때와 비교시 전치부에 증가된 응력분포를 보였다. 따라서 B형의 경우 초기에 치근의 직립효과가 있는 것으로 보인다. 3. C형 MVLAW의 경우 3급 견인고무를 걸지 않았을 경우 하악전치부를 제외하고는 응력분포를 나타내지 않았으나 견인고무를 걸었을 경우 주로 견치와 소구치 근심면에서 응력분포를 보였다. 따라서 C형의 경우 견인고무 사용시 초기에 견치와 소구치에서 치근의 직립효과가 있는 것으로 보인다.

• 대한족부족관절학회지
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• 제8권2호
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• pp.121-125
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• 2004

Purpose: We try to retrospectively evaluated the amount of dorsal angulation angle of the first metatarsal commonly occurring as the complication of proximal dome osteotomy for hallux valgus. Materials and Methods: Between January 2004 and March 2004, 34 patients who underwent proximal dome osteotomy for moderate to severe hallux valgus. Two of 34 patients were male, and thirty-two were female. The average age was 57.6 years. We measured and compared hallux valgus angle, 1st-2nd intermetatarsal angle, dorsal angulation angle of 1st metatarsal on preoperative, postoperative, postoperative 3 weeks', postoperative 3 months' X-ray. Results: Osteotomy sites were completely united on plane X-ray in all cases. The hallux valgus angle averaged $41.2^{\circ}$ ($30{\sim}60^{\circ}$) at preoperative, $4.3^{\circ}$ ($-10{\sim}20^{\circ}$) at postoperative, $5.5^{\circ}$ ($-1{\sim}20^{\circ}$) at 3 weeks after operation, $7.8^{\circ}$ ($-2{\sim}20^{\circ}$) at 3 months after operation. The 1st-2nd intermetatarsal angle averaged $17.1^{\circ}$ ($12{\sim}24^{\circ}$) at preoperative, $6.3^{\circ}$ ($0{\sim}13^{\circ}$) at postoperative, $7.2^{\circ}$ ($0{\sim}15^{\circ}$) at 3 weeks after operation, $8.7^{\circ}$ ($0{\sim}18^{\circ}$) at 3 months after operation. The dorsal angulation angle averaged $0.4^{\circ}$ ($0{\sim}3^{\circ}$) at postoperative, $1.6^{\circ}$ ($0{\sim}7^{\circ}$) at 3 weeks after operation, $2.1^{\circ}$ ($0{\sim}8^{\circ}$) at 3 months after operation. There were no statistically correlation between increase of dorsal angulation angle of the distal segment of the first metatarsal and increase of hallux valgus angle or 1st-2nd intermetatarsal angle. Conclusion: Our results shows that the dorsal angulation of distal fragment occurring after the proximal dome osteotomy in the treatment of hallux valgus may be minimized with meticulous surgery and patient's education.

• Archives of Reconstructive Microsurgery
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• 제6권1호
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• pp.29-38
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• 1997

A peripheral nerve when approximation of the ends imparts tension at the anastomosis and with a relatively long segment defect after excision of neuroma and neurofibroma cannnot be repaired by early primary suture. The one of the optimistic reconstruction method of severed peripheral nerves is to restore tension-free continuity at the repair site putting an autogenous nerve graft into the neural gap despite of ancipating motor or sensory deficit of the donor nerve area. To overcome the deficit of the autogenous nerve graft, several other conduits supplying a metabolically active environment which is able to support axon regeneration and progression, providing protection against scar invasion, and guiding the regrowing axons to the distal stump of the nerve have been studied. An author have used ipsilateral femoral vein, ipsilateral femoral vein filled with fresh thigh muscle, and autogenous sciatic nerve for the sciatic nerve defect of around 10 mm in length to observe the regeneration pattern in rat by light and electron microscopy. The results were as follows. 1. Light microscopically regeneration pattern of nerve fibers in the autogenous graft group was more abundant than vein graft and vein filled with muscle group. 2. On ultrastructural findings, the proxial end of the graft in various groups showed similar regenerating features of the axons, myelin sheaths, and Schwann cells. The fascicular arrangement of the myelinated and unmyelinated fibers was same regardless of the type of conduits. There were more or less increasing tendency in the number and the diameter of myelinated fibers correlated with the regeneration time. 3. In the middle of the graft, myelinated nerve fibers of vein filled with muscle group were more in number and myelin sheath was thinner than in the venous graft, but the number of regenerating axons in autogenous nerve graft was superior to that in both groups of the graft. The amount of collagen fibrils and amorphous materials in the endoneurial space was increased to elapsed time. 4. There was no difference in regenerating patterns of the nerve fibers of distal end of the graft. The size and shape of the myelinated nerve fbers were more different than that of proximal and middle portion of the graft. From the above results, the degree of myelination and regenerating activity in autogenous nerve is more effective and active in other types of the graft and there were no morphological differences in either ends of the graft regardless of regeneration time.

• Archives of Reconstructive Microsurgery
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• 제6권1호
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• pp.9-28
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• 1997

Adequate vascularization is pivotally essential for a successful nerve graft. Theoretically, the immediate vascularization will inhibit fibroblast infiltration and stimulate nerve cell regeneration. In this study, histomorphological and electrophysiological studies were performed to determine if vascularized grafts are functionally superior. In rat model, a 4cm segment of the sciatic nerve was obtained and placed as a non vascularized graft on one side, and as a vascularized graft connected to the inferior gluteal vessels on the opposite side. To determine the compound action potential of the gastrocnemius muscle, electromyography was done after 2, 3 and 4 months. Histomorphologically, the distribution of myelinated nerve fibers and Schwann cell were evaluated after toluidine blue staining, The following resutls were obtained: 1. The electrophysiological studies showed no difference between the nonvascularized and vascularized grafts. 2. Two and three months after grafting, myelinated nerve fibers were more abundant in the vascularized proximal, middle and distal areas in all nerve fibers of varying diameters. 3. In the post-nonvascularized graft 2-month group, a few myelinated nerve fibers were present in the proximal and middle areas, but none distally. In the post-vascularized graft 2 month group, myelinated nerve fibers ranging $2-8{\mu}m$ were present in all three areas. 4. In the post-nonvascularized graft 3 month group, a few myelinated nerve fibers ranging in $2-6{\mu}m$ were present in all three areas, but in the post-vascularized graft 3 month group, many myelinated nerve fibers ranging in $2-10{\mu}m$ were present in all three areas. 5. In the post-graft 4-month group, more myelinated nerve fibers were present in all three areas of the vascularized grafts. However, nerve fibers of less than $2{\mu}m$ in diameter were more abundant in the non vascularized grafts. 6. Schwann cells were more abundant in the proximal, middle and distal areas of the post-vascularized 2, 3 and 4-month grafts. Based on these findings, the immediate restoration of circulation in vascularized nerve grafts allows for the increased number of surviving Schwann cells, rapid healing of the axon and myelin sheath changes which occur during Wallerian degeneration, and thus is able to stimulate a morphologically optimal regeneration.

• 대한족부족관절학회지
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• 제15권2호
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• pp.51-57
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• 2011

Pilon fractures involving distal tibia remain one of the most difficult therapeutic challenges that confront the orthopedic surgeons because of associated soft tissue injury is common. To introduce and describe the diagnosis, current treatment, results and complications of the pilon fractures. In initial assessment, the correct evaluation of the fracture type through radiographic checkup and examination of the soft tissue envelope is needed to decide appropriate treatment planning of pilon fractures. Even though Ruedi and Allgower reported 74% good and excellent results with primary open reduction and internal fixation, recently the second staged treatment of pilon fractures is preferred to orthopedic traumatologist because of the soft tissue problem is common after primary open reduction and internal fixation. The components of the first stage are focused primarily on stabilization of the soft tissue envelope. If fibula is fractured, fibular open reduction and internal fixation is integral part of initial management for reducing the majority of tibial deformities. Ankle-spanning temporary external fixator is used to restore limb alignment and displaced intraarticular fragments through ligamentotaxis and distraction. And the second stage, definitive open reduction and internal fixation of the tibial component, is undertaken when the soft tissue injury has resolved and no infection sign is seen on pin site of external fixator. The goals of definitive internal fixation should include absolute stability and interfragmentary compression of reduced articular segments, stable fixation of the articular segment to the tibial diaphysis, and restoration of coronal, transverse, and sagittal plane alignments. The location, rigidity, and kinds of the implants are based on each individual fractures. The conventional plate fixation has more advantages in anatomical reduction of intraarticular fractures than locking compression plate. But it has more complications as infection, delayed union and nonunion. The locking compression plate fixation provides greater stability and lesser wound problem than conventional implants. But the locking compression plate remains poorly defined for intraarticular fractures of the distal tibia. Active, active assisted, passive range of motion of the ankle is recommended when postoperative rehabilitation is started. Splinting with the foot in neutral is continued until suture is removed at the 2~3 weeks and weight bearing is delayed for approximately 12 weeks. The recognition of the soft tissue injury has evolved as a critical component of the management of pilon fractures. At this point, the second staged treatment of pilon fractures is good treatment option because of it is designed to promote recovery of the soft tissue envelope in first stage operation and get a good result in definitive reduction and stabilization of the articular surface and axial alignment in second stage operation.

• Journal of Chest Surgery
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• 제38권8호
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• pp.583-588
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• 2005

선천성 기관 협착증은 드문 질환이며, 장분절성 기관 협착은 아주 치명적이다. 신생아나 영아에서 심한 호흡 부전이 발생하고 복합 심기형이 동반되면 수술 교정이 쉽지 않다. 선천성 심기형을 동반한 장분절성 기관 협착으로 인공 호흡기 이탈이 불가능한 2.6 kg 체중의 어린 영아 1예와 신생아 1예에 서 기관성형술을 시행하였다. 심실중격결손증 수술 후 미만성 기관 협착이 발견된 어린 영아는 기관 절제술 및 좌측 주 기관지로의 확장 문합술을 시행받았으며, 미만성 근위부 기관 협착과 팔로사징을 동반한 신생아는 활주 기관성형술과 팔로사징 완전 교정술을 동시에 시행받았다. 두 환아 모두 술후 컴퓨터 단층 촬영에서 양호한 결과를 보였으며, 현재 증상 없이 건강한 상태이다.

• Journal of Korean Neurosurgical Society
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• 제63권2호
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• pp.137-152
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• 2020

In spite of the developing endovascular era, large (15-25 mm) and giant (>25 mm) wide-neck cerebral aneurysms remained technically challenging. Intracranial flow-diverting stents (FDS) were developed to address these challenges by targeting aneurysm hemodynamics to promote aneurysm occlusion. In 2011, the first FDS approved for use in the United States market. Shortly thereafter, the Pipeline of Uncoilable or Failed Aneurysms (PUFS) study was published demonstrating high efficacy and a similar complication profile to other intracranial stents. The initial FDA instructions for use (IFU) limited its use to patients 22 years old or older with wide-necked large or giant aneurysms of the internal carotid artery (ICA) from the petrous segment to superior hypophyseal artery/ophthalmic segment. Expanded IFU was tested in the Prospective Study on Embolization of Intracranial Aneurysms with PipelineTM Embolization Device (PREMIER) trial. With further post-approval clinical data, the United States FDA expanded the IFU to include patients with small or medium, wide-necked saccular or fusiform aneurysms from the petrous ICA to the ICA terminus. However, IFU is more restrictive in South Korea than in United States. Several systematic reviews and meta-analyses have sought to evaluate the overall efficacy of FDS for the treatment of cerebral aneurysms and consistently identify FDS as an effective technique for the treatment of aneurysms broadly with complication rates similar to other traditional techniques. A growing body of literature has demonstrated high efficacy of FDS for small aneurysms; distal artery aneurysms; non-saccular aneurysms posterior circulation aneurysms and complication rates similar to traditional techniques. In the short interval since the Pipeline Embolization Device was first introduced, FDS has been firmly entrenched as a powerful tool in the endovascular armamentarium. As new FDS are developed, established FDS are refined, and delivery systems are improved the uses for FDS will only expand further. Researchers continue to work to optimize the mechanical characteristics of the FDS themselves, aiming to optimize deploy ability and efficacy. With expanded use for small to medium aneurysms and posterior circulation aneurysms, FDS technology is firmly entrenched as a powerful tool to treat challenging aneurysms, both primarily and as an adjunct to coil embolization. With the aforementioned advances, the ease of FDS deployment will improve and complication rates will be further minimized. This will only further establish FDS deployment as a key strategy in the treatment of cerebral aneurysms.

• Journal of Yeungnam Medical Science
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• 제8권1호
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• pp.79-85
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• 1991

정상대조군 20 hands와 수근관증후군환자 40 hands를 대상으로 각 1분, 2분, 5분간 수근관절굴곡 후의 신경전도속도의 변화를 측정하여 수근관증후군의 진단에 도움을 줄 수 있는지를 알아보고자 운동신경은 belly-tendon방법을, 감각신경은 역방향전도검사법을 각각 이용하여 wrist to finger segment에서 수근관절굴곡 전후의 정중신경의 SNCV와 MNDL을 측정하여 아래와 같은 결과를 얻었다. 대조군에서 수근관절굴곡 후의 신경전도속도의 변화가 있었던 경우는 감각신경에서 2 hands, 운동신경에 1 hands였으며 환자군에서는 감각신경에서 3 hands, 운동신경에서 2 hands였다. 그리고 1분, 2분 및 5분간 수근관절굴곡 후의 SNCV와 MNDL의 평균과 표준편차를 구해본 결과 대조군과 환자군에서 모두 유의한 변화가 없었다. Phlaen's wrist flexion검사에서 대조군은 5%에서 양성이었으며 환자군에서는 60%에서 양성이었다. Tinel징후는 대조군에서는 10%에서 양성이었으며 환자군에서는 33%에서 양성이었다.

• 방송공학회논문지
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• 제24권4호
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• pp.592-601
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• 2019

관상동맥 시술을 위해 혈관 조영 X-선 영상은 시술 진단 및 보조에 유용하게 활용된다. 삼차원의 복잡한 구조를 가진 관상동맥을 이차원 X-선 영상에서 기존의 단일기법만을 사용하여 정확히 분할하는 것에 어려움이 있으며, 특히 혈관이 중간에 끊어지거나 말단부위혈관이 유실되는 현상으로부터 오차가 크게 발생하는 경향이 있었다. 이러한 문제를 해결하기 위하여 기존 단일기법으로 초기분할 단계를 거친 후, 초기분할결과를 기반으로 정교한 보정영역을 설정하는 단계, 보정영역을 대상으로 패치기반 지역보정을 수행하는 단계가 수행된다. 본 연구를 통해 끊긴 혈관을 보완한 분할 결과를 구할 수 있을 뿐만 아니라 미세혈관까지 포함하지 못한 참 값의 한계점을 해결할 수 있다. 또한, 존재하는 기존 관상동맥 분할방법들에 융합하여 추가적인 성능개선을 얻어낼 수 있다. 본 논문에서는 Fully convolutional network 기반 깊은 신경망 네트워크인 U-net을 활용하였으며, 제안된 보정방법을 융합하여 기존 U-net 단일 모델 대비 성능이 상당히 개선된다는 것을 실제 여러 환자들의 데이터 셋을 통하여 증명하였다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제16권1호
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• pp.33-42
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• 1994

본교실에서는 심한 하악골 전동증 환자 5례에서 Obwegeser II method와 과두 위치 보존술 및 견고한 골간 고정을 상요하여 추적조사결과 다음과 같은 결과를 얻었다. 1. Obwegeser II method는 15mm이상의 하악골 후방이동이 요구되거나 심한 개교합의 외과적교정시에 원심골편을 수동적으로 이동시킬 수 있는 방법이라 판단된다. 2. 술후 하악과두의 위치 변화가 많은 증례 V에서 술직후 비교적 많은 재발을 경험하였다. 3. 하악과두위치의 보존과 견고한 골간고정을 통하여 악간고정기간의 단축과 술후 안정성 및 심미적 기능적 개선을 얻었다.