• 대한치과보철학회지
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• 제44권5호
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• pp.584-593
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• 2006

Statement of problem : Dental implant which has been developed gradually through many experiments and clinical applications is presently used to various dental prosthetic treatments. To conduct a successful function of implant prosthesis in oral cavity for a long time, it is important that not only structure materials must have the biocompatibility, but also the prosthesis must be designed for the stress, which is occurred in occlusion, to scatter adequately of load support. Therefore, it is essential to give the consideration about the stress analysis of supporting tissues for higher successful rates. Purpose : Recently, many implant manufacturing company produce various taper design of root form implant, the fixture is often selected. However, the stress analysis of taper form fixture still requires more studies. Material and method : This study we make the element models that five implant fixture; Branemark system(Nobel Biocare, Gothenberg, Sweden), Camlog system(Altatec, Germany), Astra system(Astra Tech, Sweden), 3i system(Implant Innovations Inc, USA), Avana system(Osstem, Korea) were placed in the area of mandibular first premolar and prosthesis fabricated, which we compared with stress distribution using the three-dimension finite element analysis under two loading condition. Results : This study compares the aspect of stress distribution of each system with the standard of Von mises stress, among many resulted from finite element analysis so that this research gets the following results. 1. In all implant system, oblique loading of maximum Von mises stress of implant, alveolar bone and crown is higher than vertical loading of those. 2. Regardless of loading conditions and type of system, cortical bone which contacts with implant fixture top area has high stress, and cancellous bone has a little stress. under the vertical loading, maximum Von mises stress is more higher in order of Branemark, Camlog, Astra, 3i, Avana. under the horizontal loading, maximum Von mises is more higher in order of Camlog, Branemark, Astra, 3i, Avana.

• 대한치과보철학회지
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• 제52권3호
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• pp.252-257
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• 2014

완전 무치악 환자에서 전악 수복시 환자 고유의 악간관계, 교합평면의 위치, 구순지지, 치아형태와 교합양상을 알 수 없기 때문에 그 모든 것을 임시의치에 기록한 후 이것을 최대한 최종 보철물에 반영하여 이상적인 보철물을 제작해 주어야 한다. 본 증례의 환자는 치주질환에 의한 다수 치아 동요가 존재하여 예후가 불량한 잔존치아 전악 발거 후 임플란트 식립하여 임시치아에 환자의 수직 및 수평 악간관계, 교합평면의 위치, 수직 및 수평 피개의 양, 치아 크기, 전치부 길이를 기록하였다. 그 후 임시치아를 스캐너와 CAD/CAM 기술을 이용하는 double scanning technique로 복제하여 임시치아와 동일한 형태의 단일 구조 지르코니아 브릿지 보철물을 제작하였다. 치료 이후 4개월간의 임상 관찰에서 환자는 심미적, 기능적으로 만족하고 안정적으로 유지되었기에 이를 보고하고자 한다.

• 구강회복응용과학지
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• 제24권3호
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• pp.299-310
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• 2008

경부골 최대응력을 안정적으로 산출하기 위해서, 경부 디자인 형상이 비교적 단순한 메가젠 임플란트 모델을 대상으로, 유한요소 모델링을 통하여 경부골의 응력분포를 계산하였다. 그리고 산출된 응력분포를 회귀분석법으로 통계 처리하여 응력 집중점의 응력을 정량화 하였다. 결과는 모든 모델에서 경부골 응력은 치밀골 외면에 집중되었으며, 그 범위는 0.5mm 이내였다. 회귀분석법을 활용하기 위해서는 mesh 정밀도가 높아야 했으며, 이 경우 특이점의 최대 응력을 안정적으로 산출 할 수 있었다.

• 대한한의학회지
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• 제28권4호
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• pp.8-12
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• 2007

Objectives : This study aimed to investigate the circadian variation in stroke types, ischemic stroke subtypes, and Sasang constitutions. Methods : 295 patients with acute stroke within 14 days onset were included, who were admitted to Kyunghee Oriental Medical Center from October 2005 to May 2007. The stroke onset time was subdivided into four groups of 6-hour intervals in a day. Stroke types, ischemic stroke subtypes, and Sasang constitutions in four groups were examined. Results : Most ischemic stroke occurred between 6:01-12:00 hours (30.2%). For ischemic stroke subtypes, the peak period of small-vessel occlusion was between 6:01-12:00 hours (33.2%), large-artery atherosclerosis was most common between 12:01-18:00 hours (39.5%), and cardiac embolism was most frequent between 18:01-24:00 hours (50%). In terms of Sasang constitution, Soyeumin and Taeyeumin were most common between 6:01-12:00 hours (36.4% versus 41.5%, respectively), but the peak time of Soyangin was between 12:01-18:00 hours (35.2%). Conclusion :Most ischemic stroke events occurred in the mid-to-late morning hours in the present study and there was a circadian variation of onset in ischemic stroke subtypes and Sasang constitution.

• Archives of Plastic Surgery
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• 제44권1호
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• pp.19-25
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• 2017

Background Numerous condylar repositioning methods have been reported. However, most of them are 2-dimensional or are complex procedures that require a longer operation time and a highly trained surgeon. This study aims to introduce a new technique using a condylar repositioning plate and a centric relation splint to achieve a centric relationship. Methods We evaluated 387 patients who had undergone surgery for skeletal jaw deformities. During the operation, a centric relation splint, intermediate splint, final centric occlusion splint, and condylar repositioning plate along with an L-type mini-plate for LeFort I osteotomy or a bicortical screw for bilateral sagittal split ramus osteotomy were utilized for rigid fixation. The evaluation included: a physical examination to detect preoperative and postoperative temporomandibular joint dysfunction, 3-dimensional computed tomography and oblique transcranial temporomandibular joint radiography to measure 3-dimensional condylar head movement, and posteroanterior and lateral cephalometric radiography to measure the preoperative and postoperative movement of the bony segment and relapse rate. Results A 0.3% relapse rate was observed in the coronal plane, and a 2.8% relapse rate in the sagittal plane, which is indistinguishable from the dental relapse rate in orthodontic treatment. The condylar repositioning plate could not fully prevent movement of the condylar head, but the relapse rate was minimal, implying that the movement of the condylar head was within tolerable limits. Conclusions Our condylar repositioning method using a centric relation splint and miniplate in orthognathic surgery was found to be simple and effective for patients suffering from skeletal jaw deformities.

• Journal of Chest Surgery
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• 제39권10호
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• pp.791-794
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• 2006

슬와동맥 포착증후군은 젊은 남성군에서 슬와동맥과 비복근, 섬유띠, 슬와근 간의 이상 관계로 하지의 파행과 혈류 장애를 유발하는 드문 질환이다. 명확한 진단이 어려우며, 대부분의 경우 수술적 치료가 병변의 결정적인 진단을 제공하며, 환자의 회복에 필수적이다. 34세 남자가 좌측 하지의 파행과 동통을 주소로 입원하였다. 상하지 지수, 혈관 초음파, 전산화 단층 혈관 조영술, 자기 공명 영상 검사상 좌측 슬와동맥 근위부의 폐쇄소견이 관찰되었다. 환자는 수술장에서 슬와동맥이 슬와근 주변의 섬유띠에 의해 둘러 싸여 폐쇄된 4형 슬와동맥 포착증후군으로 확인되었다. 완전히 폐쇄된 슬와동맥을 제거하고 동측의 대복재정맥을 이용한 치환 수술을 시행하였다. 수술 후 환자의 증상은 호전되었다.

• Journal of Chest Surgery
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• 제26권1호
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• pp.32-35
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• 1993

During the period from September 1989 through December 1992, 118 cases of coronary arterial bypass graft were performed at Department of Cardiothoracic Surgery, Asan Medical Center. Twenty-one of these had history of recent or remote percutaneous transluminal coronary angioplasty. They consisted of 13 males[age,58.7 + 5.4 years] and 8 females[age, 63.6 + 2.8years] with the mean age of 60.6. History of old myocardial infarction was noted in 24%[5/21] of the patients and congestive heart failure in 2 cases. The angina by type of presentation is unstable in all of the patients. The patterns of involvement of coronary arterial disease were left main disease[1], single vessel disease[5], double vessel involvement[10], and triple vessel involvement[5]. We performed 4 cases of single bypasses, 7 cases of double, 8 cases of triple, and 2 cases of quadruple bypasses. Total of 51 grafts[LIMA:12, RSVG:39] were inserted in 21 cases with average of 2.4 grafts per patient. The methods of myocardial protection were cold blood cardioplegia[8 cases], intermittent aortic occlusion[11], and continuous coronary perfusion with local coronary sharing[2]. There were no operative or late death. The only cardiac complication was 1 case of low cardiac output required IABP. The other complications were 1 case of sternal wound infection and 1 case of postoperative bleeding required reoperation. And there was no case of perioperative myocardial infarction. Postoperatively, 3 cases of recurrent angina were detected at 5, 7, and 18months after surgery. One of them was managed successfully with repeat PTCA[who was recurred 18 months postoperatively], and the other two with medication. I conclude that we can approach the patients more aggressively with PTCA, because of our acceptable operative risks.

• 구강회복응용과학지
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• 제22권1호
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• pp.101-110
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• 2006

This study was performed to investigate the surface properties and in vitro biocompatibility of electrochemically oxidized Ti-6Al-7Nb alloy by anodic spark discharge technique. Discs of Ti-6Al-7Nb alloy of 20 mm in diameter and 2 mm in thickness were polished sequentially from #300 to 1000 SiC paper, ultrasonically washed with acetone and distilled water for 5 min, and dried in an oven at $50^{\circ}C$ for 24 hours. Anodizing was performed using a regulated DC power supply. The applied voltages were given at 240, 280, 320, and 360 V and current density of $30mA/cm^2$. Hydrothermal treatment was conducted by high pressure steam at $300^{\circ}C$ for 2 hours using a autoclave. Samples were soaked in the Hanks' solution with pH 7.4 at $36.5^{\circ}C$ during 30 days. The results obtained were summarized as follows; 1. The oxide films were porous with pore size of $1{\sim}5{\mu}m$. The size of micropores increased with increasing the spark forming voltage. 2. The main crystal structure of the anodic oxide film was anatase type as analyzed with thin-film X-ray diffractometery. 3. Needle-like hydroxyapatie (HA) crystals were observed on anodic oxide films after hydrothermal treatment at $300^{\circ}C$ for 2 hours. The precipitation of HA crystals was accelerated with increasing the spark forming voltage. 4. The precipitation of the fine asperity-like HA crystals were observed after being immersed in Hanks' solution at $37^{\circ}C$. The precipitation of HA crystals was accelerated with increasing the spark forming voltage and the time of immersion in Hanks' solution. 5. The Ca/P ration of the precipitated HA layer was equivalent to that of HA crystal as increasing the spark forming voltage and the time of immersion in Hanks' solution.

• 구강회복응용과학지
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• 제30권2호
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• pp.176-183
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• 2014

심하게 흡수된 치조제는 기능적인 하중을 견디기 어렵고 구강 조직의 유해 변화와 더불어 환자의 의치 적응을 어렵게 한다. 환자의 불편감을 해소하고 의치의 안정성과 유지력을 증가시키기 위해 임플란트를 이용한 피개의치가 치료 방법으로 선택될 수 있다. 로케이터 부착장치는 사용상의 편리성이 높으며 다양한 유지력을 갖는 남자부를 보유함으로써 임상에서 볼 형태 부착장치대용으로 많이 사용되고 있다. 본 증례는 77세 여자환자로서 낮은 수직고경과 심한 치조제 흡수를 보이는 상하악 무치악 상태였다. 이에 하악에 4개의 임플란트를 식립하고, 상악은 총의치, 하악은 로케이터 부착장치를 이용한 임플란트 피개의치로 수복하여 기능 및 심미적으로 만족할 만한 결과를 얻었기에 이를 보고하고자 한다.

• 대한구순구개열학회지
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• 제15권2호
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• pp.69-82
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• 2012

Our Team Approach consists of following five stages; (1) Peri-natal care until lip repair After ultrasound diagnosis, some obstetricians recommend the mother with CL/P fetus to undergo prenatal counseling in our CLP clinic. On the day the CL/P baby was born, our oral surgeon, nurse, and pedodontist visit the maternity clinic, and take counseling and take impression for a feeding plate. The cheiloplasty is performed in three months old. (2) From lip repair to palatal repair At one year of age, Otorhinolaryngologist checks middle-ear disease. Palatoplasty is carried out at 1.5 - 2 years old. (3) In deciduous and early mixed dentitions Speech is the most important issue in social life for the CL/P subjects, therefore the training of velopharyngeal function is essential. Orthodontist monitors dentofacial development from 5 years of age. In the case of severe maxillary under-growth or severe collapse, maxillary protractor or lateral expansion is indicative, respectively. In early mixed dentition, upper central incisor on the cleft area erupts with some torsion, and then the traumatic occlusion with tooth torsion must be corrected. (4) In mixed dentition Right before the eruption of upper canines, secondary bone grafting is performed. One year prior to the operation, maxillary fan-type expansion is carried out to correct the collapse of maxillary segments. Following the surgical operation, the erupted canine will be moved into the transplanted bone to avoid alveolar resorption. (5) In permanent dentition Final tooth alignment is carried out after eruption of second molars. Some cases may require orthognathic surgery after physical maturation. Prosthetic oral rehabilitation including the dental-implant is carried out after age eighteen.