• Steel and Composite Structures
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• v.1 no.1
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• pp.17-32
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• 2001

The Rosette-joining system is a completely new press-joining method for cold-formed steel structures. One Rosette-joint has a shear capacity equal to that of approximately four screws or rivets. The Rosette thin-walled steel truss system presents a new fully integrated prefabricated alternative to light-weight roof truss structures. The trusses are built up on special industrial production lines from modified top hat sections used as top and bottom chords and channel sections used as webs which are joined together with the Rosette press-joining technique to form a completed structure easy to transport and install. A single web section is used when sufficient but can be strengthened by double-nesting two separate sections or by using two lateral profiles where greater compressive axial forces are met. An individual joint in the truss can be strengthened by introducing a hollow bolt into the joint hole. The bolt gives the connection capacity a boost of approximately 20%. A series of laboratory tests have been carried out in order to verify the Rosette truss system in practice. In addition to compression tests on individual sections of different lengths, tests have also been done on small structural assemblies and on actual full-scale trusses of a span of 10 metres. Design calculations have been performed on selected roof truss geometries based on the test results, FE-analysis and on the Eurocode 3 and U.S.(AISI) design codes.

• Journal of Veterinary Clinics
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• v.28 no.3
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• pp.328-331
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• 2011

Two dogs presented to the Dueckso Animal Hospital with a history of intermittent lameness of the left forelimb. On physical examination, a visible antebrachial deformity that resulted in gross external rotation of approximately $90^{\circ}$ was observed in two dogs. Medial-lateral radiographic views revealed distal ulnar subluxation, cranial bowing of the radius, radial and ulnar shortening, and external rotation of the paw. A distal ulnar ostectomy and distal radial closing wedge osteotomy were performed in two dogs. A proximal ulnar osteotomy was performed, adjacent to the elbow joint in case 1. Then, the osteotomized site was supported with an intramedullary pin. A T-plate and cortical screws were applied to the proximal and distal radial segments after derotating the distal segment internally. Postoperative radiographic view verified the correction of the angular deformity in two dogs. The follow-up was completed by physical examination 6 and 10 months after surgery respectively. There was no evidence of lameness of the left forelimb in two dogs. Gross observation of the limb revealed an apparent appropriate correction of the rotational and angular deformity in two dogs.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.6 no.2
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• pp.60-64
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• 2013

After volar locking plating of distal radius fracture, complications arising from unrecognized dorsally prominent screws penetrating the extensor compartments are increasingly reported. However, standard radiography and fluoroscopy may not adequately visualize screw lengths, because of complex shape of dorsal cortex of the distal radius. We presented case of ultrasonography diagnosis of extensor tenosynovitis caused by dorsal screw prominence after volar plate fixation of distal radius fracture.

• Journal of Korean Foot and Ankle Society
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• v.19 no.1
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• pp.35-38
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• 2015

The checkrein deformity describes tethering of the flexor hallucis longus tendon, which mainly occurs after fracture of the distal tibia. The deformity increases with dorsiflexion of the ankle and decreases or disappears with plantarflexion of the ankle. In some cases, the deformity may occasionally include the second and third toes. In the current study, the authors experienced secondary checkrein deformity of all lesser toes after open reduction and plate fixation for comminuted fracture of the calcaneus. As a treatment, plate and screws were removed, followed by an additional medial incision which showed a partially ruptured flexor digitorum longus tendon with severe adhesion. Resection of the adhesed tendon and tenodesis of its distal portion to the flexor hallucis longus was performed for correction of the checkrein deformity. Then the lessor toe checkrein deformity recovered immediately. The authors report on this rare lessor toe checkrein deformity after calcaneal fracture fixation with a review of literature.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.6
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• pp.472-479
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• 2002

Since $Br^{\circ}anemark$ introduced the osseointegrated implants, they have been granted for useful methods for the restoration of oral function. The original $Br^{\circ}anemark$ protocol recommended long stress-free healing periods to achieve the osseointegration of dental implants. However, many clinical and experimental studies have shown that the osseointegration is no wonder in almost cases and that early and immediate loading may lead to predictable osseointegration. So we are willing to introduce the Satellite Abutment newly invented for immediate loading. We think that it will make the occlusal forces dispersed to surrounding bone and that we can restore the oral function immediately after implant installation not disturbing osseointegration. In case of using Satellite abutment, stress concentrated to bone contact area of implant was distributed not only fixation plate and screws but also superior, middle portion of implant and cortical layer of jaw bone. It was clearly decreased on the bone contact surfaces around dental implants. 1. Stress was decreased more than 76.5% when satellite straight abutment was used. 2. Stress was decreased more than 50% when satellite angled abutment was used. 3. The stress around dental implant was well distributed along the cortical bone surface and the fixation plate and screw. This study concludes that satellite abutment can be used as all immediate loading implant prothesis because it was possible to distribute periimplant occlusal stress through implant contact bone surface and cortical layer of jaw bone.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.4
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• pp.255-263
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• 2011

Introduction: Maxillomandibular fixation (MMF) is essential before surgery under general anesthesia in maxillofacial trauma patients. MMF is used basically to reconstruct the occlusion and occlusal stability to recover the facial shape and oral functions. The arch bar and wire is a traditional method for MMF, but it can not only bring pressure to the periodontal ligaments and teeth but also cause a penetrating injury to the surgeons. Materials and Methods: In this study, 198 patients with an open reduction using a manual reduction without MMF from September 2005 to May 2010 in Dankook University Dental Hospital were subjected to a follow-up evaluation during the postoperative 4 months periods. This study evaluated the incidence of complications according to the condition of the patient (gender, age), the state of bony union of the fracture sites and a numeric rating scale evaluation for postoperative pain scoring. Results: 1. The complications were classified into major and minor according to the seriousness, and the major complication rate was as low as 2.02%. Only 2 cases of re-operations (1.01%) were encountered. In the classification according to the fracture line, plate fracture was observed in both cases of mandibular symphysis fracture, and angle fractures and loosening of two screws were noted in the case of mandibular angle fracture. 2. The complication rate was similar regardless of gender and age. 3. The degree of bony union was satisfactory, and the complication rate was reduced as the bony union improved. 4. More patients complained of pain as the operation time was increased. Conclusion: The use of MMF is not always necessary if a skilled assistant is provided to help manually reduce the fracture site. Compared to other studies of mandibular fracture surgery using MMF, the complication rate was similar using only manual reduction and the patients' discomfort was reduced without MMF.

• Journal of Dental Rehabilitation and Applied Science
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• v.18 no.4
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• pp.301-311
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• 2002

The purpose of this study was to compare the distributing pattern of stress on the finite element models with the different vertical bone level of implant fixture. The two kinds of finite element models were designed according to vertical bone level around fixture ($4.0mm{\times}11.5mm$). The cemented crowns for mandibular first and second molars were made. Three- dimensional finite element model was created with the components of the implant and surrounding bone. Vertical loads were applied with force of 200N distributed within 0.5mm radius circle from the center of central fossa and distance 2mm and 4 mm apart from the center of central fossa. Von-Mises stresses were recorded and compared in the supporting bone, fixtures, abutment screws, and crown. The results were as following : (1) In vertical loading at the center circle of central fossa on model 1 and 2, the difference from vertical bone in implant placement did not affect the stress pattern on all components of implant except for crown. (2) With offset distance incerasing and the bone level of implant decreasing, the concentration of stress occured in the buccal side of long crown, around the buccal crestal bone, and on the fixture- abutment interface. As a conclusion, the research showed a tendency to increase the stress on the supporting bone, fixture and screw under the offset loads when the vertical level of bone around fixture was different. Since the same vertical bone bed has more benefits than the different bone bed around fixtures, it is important to prepare a same vertical level of bone bed for the success of implants under occlusal loads.

• Journal of Digital Contents Society
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• v.11 no.4
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• pp.553-559
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• 2010

By applying the various reformation techniques by using a circle raw data of after computed tomography image in the patient enforcing the spine screw fixation, this research tried to look into the various information including the exact location of the position of the screw spike and accuracy of an operation. In a clinical, by applying the or multi planar reformatting(MPR), that is the re-composition technique used mainly, maximum intensity projection (MIP), and volume rendering technique(VRT) and transformation removal from a register modifying VRT, video data were compared and were analyzed by the quantitative method and qualitative method. It is judged as the transformation volume rendering technique of the re-composition technique which is most useful in minimizing the artifact shadow by the exact location of the position of a screw and metal among the analysis and evaluation result computed tomography image reformation technique of the reformation image after the spine screw fixation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.5
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• pp.444-450
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• 2007

In general, labiolingual or buccolingual widths of residual alveolar bone are insufficient in edentulous area, because of alveolar resorption. Horizontal augmentation is bone graft procedure with a view to reinforcing horizontally insufficient bone quantity for installation of implants. The standard method is taking appropriate amount of block bone from intraoral or extraoral autogenous bone, and solid fixation with screws or mini-plate on labial or buccal side of residual alveolar bone. The purpose of this study is to discuss clinical usefulness of horizontal augmentation with autogenous block bone by observation and analysis of course of 41 implants installed to 12 patients by horizontal augmentation in Seoul National University Bundang Hospital from July, 2002 to December, 2005. The mean age of patients is 52.7, from 19 to 70, and the number of men and women is each 2 and 10. Block bone was taken from symphysis, body, ramus of mandible or iliac bone. And 6 types of implants were installed simultaneously or not, the diameters of implants are from 3.3 to 5.5mm, the lengths are from 8 to 15mm. The operator added artificial bone grafting material and optionally covered with membrane. The mean periods of observation after operation and final prosthetics were 28.6 and 17.0 months. As a result, 40 among 41 implants survived, the survival rate was 97.6%. Average 0.9mm crestal resorption was observed at final point of time by periapical view of each patients. Major complication related to the procedure was numbness in 7 patients.

• Imaging Science in Dentistry
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• v.40 no.3
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• pp.123-129
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• 2010

Purpose : To evaluate the effect of surgical treatment of ligature-induced peri-implantitis in dogs using fractal analysis. Also, the capabilities of fractal analysis as bone analysis techniques were compared with those of histomorphometric analysis. Materials and Methods : A total of 24 implants were inserted in 6 dogs. After a 3-months, experimental periimplantitis characterized by a bone loss of about 3 mm was established by inducing with wires. Surgical treatment involving flap procedure, debridement of implants surface with chlorhexidine and saline (group 1), guided bone regeneration (GBR) with absorbable collagen membrane and mineralized bone graft (group 2), and $CO_2$ laser application with GBR (group 3) were performed. After animals were sacrificed in 8 and 16 weeks respectively, bone sections including implants were made. Fractal dimensions were calculated by box-counting method on the skeletonized images, made from each region of interest, including five screws at medial and distal aspects of implant, were selected. Results : Statistically significant differences in the fractal dimensions between the group 1($0.9340{\pm}0.0126$) and group 3($0.9783{\pm}0.0118$) at 16 weeks were found (P<0.05). The fractal dimension was statistically significant different between 8($0.9395{\pm}0.0283$) and 16 weeks in group 3 (P<0.05). These results were similar with the result of the evaluation of new bone formation in histomorphometric analysis. Conclusions : Treatment of experimental peri-implantitis by using $CO_2$ laser with GBR is more useful than other treatments in the formation of new bone and also the tendency of fractal dimension to increase relative to healing time may be a useful means of evaluating.