• Archives of Plastic Surgery
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• 제33권4호
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• pp.445-448
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• 2006

Purpose: The nose is the most prominent skeletal feature of the face and is thus prone to frequent injury. Closed reduction of nasal bone fractures can be performed under general or local anesthesia. However, the benefits and the drawbacks in either form of anesthesia chosen are seldom perceived by the surgeon. A retrospective study was performed to assess the differences in the outcome among the two groups subjected to surgery under different type of anesthesia and to introduce our method of local anesthesia and its adequacy. Methods: Two hundred and fifteen patients during a 2-year period were included in the study. 2% Lidocaine mixed with 1:100,000 epinephrine was injected on the anterior ethmoid nerve and the periosteum. Assessment factors included intra-operative adequacy of analgesia, post-operative analgesic requirement and functional and aesthetic outcome of surgery. Results: 19 patients were manipulated under general anesthesia and 196 patients were manipulated under local anesthesia on the anterior ethmoidal nerve and dorsal periosteum. No statistically signigicant variable in performance of surgery could be attributed to the mode of anesthesia employed(p > 0.05). Four patients experienced complications after reduction. One developed septal deviation and three nasal obstruction. But, no secondary operations were needed. Conclusion: Anterior ethmoidal nerve block and dorsal periosteal injection of 2% Xylocaine, combined with topical intranasal 4% lidocaine and epinephrine provided sufficient analgesia comparable to that of general anesthesia.

• 대한치과의사협회지
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• 제44권2호통권441호
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• pp.115-122
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• 2006

Objective : The purpose of this study was to evaluate the dimensional errors between real tooth, 3D CT image and CARP model. Materials and Methods : Two maxilla and two mandible block bones with intact teeth were taken from two cadavers. Computed tomography was taken either in dry state and in wet state. After then, all teeth were extracted and the dimensions of the real teeth were measured using a digital caliper at mesio-distal and bucco-lingual width both in crown and cervical portion. 3D CT image was generated using the V-works $4.0^{TM}$ (Cybemed Inc., Seoul, Korea) software. Twelve teeth were randomly selected for CARP model fabrication. All the measurements of 3D Ct images and CARP models were made in the same manner of the real tooth group. Dimensional errors between real tooth, 3D CT image model and CARP model was calculated. Results : 1) Average of absolute error was 0.199 mm between real teeth and 3D CT image model, 0.169 mm between 3D CT image model and CARP model and 0.291 mm between real teeth and CARP model, respectively. 2) Average size of 3D CT image was smaller than real teeth by 0.149 mm and that of CARP model was smalier than 3D CT image model by 0.067mm. Conclusion : Within the scope of this study, CARP model with the 0.291 mm average of absolute eror can aid to enhance the success rate cf autogenous tooth transplantation due to the increased accuracy of recipient bone and donor tooth.

• 대한치과보철학회지
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• 제33권1호
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• pp.130-143
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• 1995

The purpose of this study was to analyze the magnitude and distribution of stress using photoelastic model with the rigid connection using T-block attachment and non-rigid connection using key & keyway attachment. The vertical load of 16 Kg was applied on the central fossa of the tooth, the pontic and the implant, and the pattern and distribution under each condition was analyzed. The following results were obtained : 1. In case of vertical load on the central fossa of the implant, the stress was concentrated at the apex of the implant involving the mesial alveolar bone in both fixed partial denture with the rigid connection and that with the nonrigid connection and the stress concentration at the mesial cervical area of the implant was a little more in the nonrigid connection than in the rigid connection. 2. In case of vertical load on the central fossa of the pontic, the stress was concentrated at the apex of 2nd bicuspid in both 3 unit fixed partial denture with nonrigid connection and that with the rigid connection. The stress was more concentrated at the mesial alveolar bone of the implant, but the stress distribution at the natural teeth more favorable at the rigid connection than at the non-rigid connection in case of 4 unit fixed partial denture. 3. In case of vertical load of the central fossa of the 2nd bicuspid, much stress with 3 fringe order was observed at the apex of the 2nd bicuspid in the 3 unit fixed partial denture, but relatively even stress distribution was observed at the apex of the implant, the 1st and 2nd bicuspid, and the adjacent cuspid in the 4 unit fixed partial denture.

• Journal of Periodontal and Implant Science
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• 제30권4호
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• pp.793-803
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• 2000

Procedures for treatment of molar furcation invasion defects range from open flap debridement, apically repositioned flap surgery, hemisection, tunneling or extraction, to regenerative therapies using bone grafting or guided tissue regenerative therapy, or a combination of both. Several clinical evaluations using regenerative techniques have reported the potential for osseous repair of treated furcation invasions. Regenerative treatment of maxillary molars are more difficult due to the multiple root anatomy and multiple furcation entrances therefore, purpose of this study was to evaluated histologically self-curing glass-ionomer cement and light-curing glass-ionomer cement as a barrier in the treatment of a bi-furcated maxillary premolar. Five adult beagle dogs were used in this experiment. With intrasulcular and crestal incision, mucoperiosteal flap was elevated. Following decortication with 1/2 high speed round bur, degree II furcation defect was made on maxillary third(P3), forth(P4) and fifth(P5) premolar. 2 month later experimental group were self-curing glassionomer cement and light-curing glassionomer cement. After 4, 8 weeks, the animals were sacrificed by vascular perfusion. Tissue block was excised including the tooth and prepared for light microscope with Gomori's trichrome staining. Results were as follows. 1. In all experiment group, there were not epithelial down growth and glass ionomer cement were encapsulated connective tissue. 2. In 4 weeks experiment I group slighly infiltrated inflammatory cells but not disturb the new bone or new cementum formation. 3. In 8 weeks, experiment groups I, II were encapsulated fine connective tissue. 4. Therefore glass-ionomer cement filling to the grade III maxillary furcations with multiple root anatomy and multiple furcation entrances were possible clinical methods and this technique is useful method for Maxillary furcation involvement.

• Investigative Magnetic Resonance Imaging
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• 제8권2호
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• pp.100-108
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• 2004

목적 : Trypsin으로 관절연골의 변성을 인공적으로 유도한 뒤 관절연골의 구성성분인 glycosaminoglycan(GAG)의 소실을 생화학적으로 정량분석하고 $Gd(DTPA)^{2-}$-(gadolinium diethylene triamine pentaacetic acid)조영증강, 그리고 T1, T2, rho 이완시간등과 어떤 상관관계가 있는지를 조사함으로써 관절연골의 초기 퇴행성 변화에 대해서 자기공명영상(MRI)으로 관찰이 가능한 지를 알아보고자 하였다. 대상 및 방법 : 적출된 3개의 돼지 슬개골에서 실험에 사용될 관절연골조각을 폭 8 mm, 길이 10 mm 크기의 관절연골조각을 3개 만들었다. 분광광흡수계(spectrophotometry)에서 dimethylmethylene blue를 이용한 chondroitin sulfate standard의 흡수도를 측정하여 GAG을 정량분석 하였다. 관절연골을 배양할 용액은 0.2 mg/ml trypsin, 1 mM $Gd(DTPA)^{2-}$ 첨가된 trypsin, 그리고 대조군용 인산염완충식염수(phosphate buffered saline, PBS)의 3가지를 준비하였다. 배양시간은 1시간에서 5시간까지는 매시간마다 배양하였고 24시간과 48시간까지 배양하였다. MRI촬영은 1시간에서 5시간까지만 매시간마다 배양후 시행하였다. 1.5T 기기에서 MRI촬영은 T1강조영상(TR/TE, 450/22)과 혼합에코기법(mixed echo sequence) (TR/TE, 760/21-168, 8 echoes)등을 시행하였다. 모든 촬영에서 영상영역은 50 mm, 절편두께는 2 mm, 그리고 매트릭스는 $256\times512$ 였다. MRI촬영자료에서 관절연골부위를 픽셀단위로 비교분석 하였다. 배양이 끝난 관절연골은 hematoxylin & eosin, toluidine blue, alcian blue, trichrome 염색 등을 시행하여 관찰하였다. 결과 : Dimethylmethylene blue를 이용한 GAG의 정량분석결과 배양시간증가에 따라 GAG의 농도가 비례적으로 증가하였다. $Gd(DTPA)^{2-}$ 첨가된 trypsin배양에서 관절연골의 T1 강조 영상에서의 신호강도는 trypsin 배양에 비하여 평균 $42.0\%$ 증가하였고 4시간과 5시간배양에서는 trypsin에서만 배양한 관절연골에 비하여 신호강도가 더욱 뚜렷하게 증가되었다 (p<0.05). 관절연골의 T1, T2, rho 이완시간은 배양시간에 따라 유의성 있는 차이가 관찰되지 않았으나 $Gd(DTPA)^{2-}$ 첨가된 trypsin배양에서 T1이완시간의 증가가 관절연골의 표층부와 이행부에서 측정되었다. 조직검사결과 trypsin 배양의 관절연골에서 toluidine blue와 alcian blue염색에서 결손이 관찰되었다. 결론 : Trypsin 배양시간에 따라 관절연골의 GAG결손을 정량적으로 확인할 수 있었고 픽셀크기 $97.9\times195\;{\mu}m$인 MRI로 $Gd(DTPA)^{2-}$-조영증강 및 이완시간을 측정할 수 있었다. 배양시간에 따른 GAG결손은 T1, T2, rho 이완시간보다 $Gd(DTPA)^{2-}$-조영증강에서 유의한 차이를 관찰할 수 있었다. 그러므로 관절연골의 초기 퇴행성 변화를 진단하는 데는 T1강조영상에서 $Gd(DTPA)^{2-}$-조영증강정도를 비교하는 것이 가장 유용할 것으로 사료된다.

• 대한치과교정학회지
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• 제21권2호
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• pp.259-272
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• 1991

Orthodontic traction has been suggested as the treatment of choice for intrusive luxation injuries. Prior research has shown orthodontic forces to be ineffective in the presence of ankylosis or in cases with zero mobility following the injury. If orthodontic traction is to be effective, it must be initiated prior to the onset of ankylosis. The purpose of this study was to describe the effects of intrusive luxation at various times following the injury, and to determine the time of the onset of ankylosis, and to examine what effect immediate partial luxation has on the onset of ankylosis. Eight young mongrel dogs were utilized for this study. Intrusive luxation was produced with an axial impact using a gravity hammer and a specially designed holding device on 4 teeth (2 max. and 2 man. first premolars) in each dog. The teeth were intruded approximately 3-4mm in an axial direction. One maxillary and one mandibular premolars were partially luxated with the other two teeth being untouched. Pre and posttrauma tooth position was documented with plaster models and radiographs taken with an individualized X-ray jig. Dogs were sacrificed immediately following the injury and at 1, 2, 4, 7, 10, 14 and 21 days respectively. Tetracycline was administered as a vital bone marker 24 hours before sacrifice. Block sections of the tooth and alveolus were prepared for decalcified and non decalcified histologic sections. The effects of traumatic intrusion were analyzed by means of model casts, radiographs, tetracycline bone marking and histologic preparations. The results obtained were as follows: 1. The animal sacrificed immediately following the injury displayed alveolar fractures, torn periodontal ligaments, and areas of direct tooth-bone contact. 2. The odontoblastic layer of the pulp was disorganized as early as 24 hours after the injury. 3. Bony remodeling was noted at 4 days along with active surface resorption. 4. Ankylosis was first seen 7 days after the injury. 5. Osteogenesis in the dentin (thick tetracycline bands) was observed 7 days after the injury. 6. There was no progressive root resorption and ankylosis where the periodontal ligament has been healed. 7. The Luxated group showed significantly more root resolution and ankylosis than the Nonluxated group with increased observation periods. The results suggest that ankylosis may occur within the first week following the injury, and hence orthodontic traction should be initiated as soon after the injury as possible.

• Journal of Periodontal and Implant Science
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• 제30권2호
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• pp.257-277
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• 2000

New techniques for regenerating the destructed periodontal tissue have been studied for many years. Current acceptable methods of promoting periodontal regeneration are basis of removal of diseased soft tissue, root treatment, guided tissue regeneration, graft materials, and biological mediators. Platelet Rich Plasma has been reported as a biological mediator which regulates activities of wound healing progress including cell proliferation, migration, and metabolism. The purpose of this study is to evaluate the effects of using the Platelet Rich Plasma as a regeneration promoting agent for furcation involvement defect. Five adult beagle dogs were used in this experiment. The dogs were anesthetized with Ketamin HCl(0.1 ml/kg, IV)and Xylazine hydrochloride($Rompun^{(R)}$, Bayer, 0.1 ml/kg, IM) and conventional periodontal prophylaxis were performed with ultrasonic scaler and hand instruments. With intrasulcular and crestal incision, mucoperiosteal flap was elevated. Following decortication with 1/2 high speed round bur, degree II furcation defect was made on mandibular third(P3), forth(P4) and fifth(P5) premolar, and stopping was inserted. After 4 weeks, stopping was removed, and bone graft was performed. Ca-P was grafted in P3(experimental group I), Combination of Ca-P and plasma rich platelet were grafted in P4(experimental group II), and P5 was remained at control group.Systemic antibiotics(gentamicin sulfate)and anlgesics(phenyl butazone) were administrated intramuscular for 2 weeks after surgery. Irrigation with 0.1% Chlorhexidine Gluconate around operate sites was performed during the whole experimental period except one day immediate after surgery. Soft diets were fed through the whole experiment period. After 4, 8 weeks, the animals were sacrificed by perfusion technique. Tissue block was excised including the tooth and prepared for light microscope with Gomori's trichrome staining. At 4 weeks after surgery, there were rapid osteogenesis phenomenon on the defected area of the Platelet Rich Plasma plus Ca-P BBP group and early trabeculation pattern was made with new osteoid tissue produced by activated osteoblast. Bone formation was almost completed to the fornix of furcation by 8 weeks after surgery. In conclusion, Platelet Rich Plasma can promote rapid osteogenesis during healing of periodontalregeneration.

• Archives of Hand and Microsurgery
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• 제23권4호
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• pp.248-253
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• 2018

목적: 변형-내초점 핀 고정술을 통한 골성 망치 수지의 해부학적인 직접 정복에 대한 임상적 결과를 알아보고자 한다. 방법: 2014년 3월부터 2017년 10월까지 18명의 골성 망치 수지 환자를 대상으로 K-강선을 이용하여 골편을 직접 정복하는 방법인 변형-내초점 핀 고정술을 시행하였다. 수술 후 통증, 관절 운동 범위, 방사선적인 평가를 시행하였다. 또한 골유합 시기, 기능 회복 정도, 합병증 발생률을 평가하였고, 수술 후 기능적 예후를 판정하기 위해 Crawford의 평가 기준을 이용하였다. 결과: 평균 6주(5-7주)에 방사선적 골유합을 얻었다. 전체 환자에서 평균 $2.8^{\circ}$ ($0^{\circ}-10^{\circ}$)의 신전 소실(extension loss)이 발생하였다. 모든 환자에서 관절면의 일치와 만족스러운 관절면의 재형성이 관찰되었으며, 최종 외래 추시에서 원위지간 관절의 평균 굴곡각은 $72.2^{\circ}$ ($70^{\circ}-75^{\circ}$)였다. Crawford의 평가 기준으로 아주 만족이 12명(66.7%), 만족이 6명(33.3%)이었다. 결론: 변형-내초점 핀 고정술은 골편을 직접 정복 후 고정하여 해부학적 정복을 얻는 방법으로 기존의 다른 경피적 핀 고정술들과 결합하여 적절한 적응증에 적용한다면 좋은 결과를 얻을 수 있을 것으로 기대한다.

• Clinics in Shoulder and Elbow
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• 제2권1호
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• pp.8-13
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• 1999

The results of the operative treatment of the Grade III acromioclavicular joint injury is defined by the durability of the reduced joint and free of exertional pain. Several surgical techniques have been applied to reduce and stabilize the joints effectively. Resection of clavicular lateral end and subacromial decompression also could be applied to prevent post-operative arthritic change. Biomechanical studies reveals the role of clavicular elevation and rotation to achieve more than 90 degrees of elevation. It also serves as a attachment site of deltoid and trapezius muscle. The stability and mobility of the both acromioclavicular and coracoclavicular joint are important to get full functional recovery. We modified the methods of coracoacromial ligament transfer described by Weaver-Dunn and by Shoji et a!. to pre­vent pullout of the transferred ligament and to get more improved functional results. Main technical point was harvesting full thickness bone block and fix it through the key-hole to reduce pull out angle.

• Journal of Welding and Joining
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• 제21권2호
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• pp.50-56
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• 2003

Metal matrix composites(MMC) consist of metal matrix into which is distributed a second solid phase. The normal intension is to develop a material with superior mechanical properties (for example increased toughness, stiffness and wear resistance) compared to those inherent in the matrix component. In this study, WC-12%Co/low carbon steel MMC overlays have been prepared by Gas Metal Arc Welding(GMAW) according to feeding rate of WC-12%Co grit. The macro and microstructures were examined using optical microscopy (OM) and scanning electron microscopy(SEM) each other. The characteristics of hardness and wear resistance have been investigated. WC-12%Co/low carbon steel MMC overlays which have been taken good beads without porosity and cracks were manufactured by method of GMAW. Matrix of overlayed surface was seen as fish bone and faceted dendrite structures. It was known that structures were iron tungsten carbides, Fe$_{6}$W$_{6}$C which have been occurred by melting of WC-12%Co grits. After MMC had been tested by block-roll wear test it was known that WC-12%Co/low carbon steel MMC has a excellent wear resistance by exiting Fe6w6c and WC-12%Co grit. The consequence was that region of overlay with Fe$_{6}$W$_{6}$C phase has been showed a model of adhesive wear, but region of overlay with WC-12%Co grit was restrained as a result of mechanism that wear of WC-12%Co grit is not adhesive but fracture.racture.