• The Journal of the Korean bone and joint tumor society
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• v.8 no.3
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• pp.96-105
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• 2002

Purpose: The purpose of this study was to assess the oncologic results and functional outcomes of limb salvage surgery performed in patients of primary bone tumors of the shoulder girdle. Materials and Methods: Twenty-nine patients who underwent limb sparing resection for shoulder girdle neoplasm between 1982 and 2001 were analyzed. Follow up periods averaged 7 years and 1 month. Mean age of the patients was 35 (11~71) years. There were 14 males and 15 females. Primary malignant bone tumors of shoulder girdle (proximal humerus 21, scapula 3, both 1) were 23 cases; osteosarcomas 7, chondrosarcoma 14, parosteal osteosarcoma 1, hemangioendothelioma 1, and giant cell tumor of proximal humerus were 6 cases. Limb salvage surgery was performed by curettage and cementing in 7 patients, by cement molding arthroplasty in 10 patients, and by tumor prosthesis in 7 patients, by other method such as resection only, bone graft, arthrodesis in 5 patients. The Musculoskeletal Tumor Society functional rating system was used to assess functional outcomes. Results: One osteosarcoma and 2 chondrosarcoma patients died, and the survival of the salvaged limb was 88.6% at the final follow-up. There were 6 local recurrences, 2 lung metastases, 2 local recurrences and lung metastases. The functional outcome was 80%. There was statistically significant difference of functional results among the patients treated by cement filling (86%), cement molding arthroplasty and IM nailing (71%), and tumor prosthesis (83%). (p=0.034) There were three complications including 1 radial nerve palsy and 1 axillary nerve palsy, and 1 wound infection. Dislodgement of vascularized fibular graft in one patient was treated by internal fixation. Conclusion: Limb salvage surgery seems to be useful method to treat bone tumors of the shoulder girdle.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.4
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• pp.487-496
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• 2021

Full mouth rehabilitation is re-organizing the occlusion of the remaining teeth and missing teeth considering the functions, esthetics, and neuromuscular harmony. With the loss of multiple teeth, the patient's occlusal plane gradually collapses and the vertical dimension can be reduced. Since reduced vertical dimension can be a potential etiology of the temporomandibular joint and masticatory muscles, prosthetic restoration with increased vertical dimension is required. This case report is about a 68 years old patient with vertical dimension loss due to worn dentition and multiple loss of teeth. In this case, the loss of vertical dimension is assessed carefully using the digital dentistry technology. Using CAD software in digital analysis step, the occlusal plane was established and evaluated using several criteria. Orienting the position of the bone and teeth using CBCT image, patient's condition was visualized in 3 dimension and treatment planning was possible virtually. The information that matches the patient's condylar position with the articulator, which is the virtual face bow, is reproduced on the actual articulator, and evaluated again. After the evaluation, provisional prosthesis was fabricated and it was confirmed that the patient adapts without any abnormality. This was implemented as a final prosthesis. As a result, the patient obtained satisfying results, utilizing the benefits of digital dentistry technology and traditional methods.

• The Journal of the Korean bone and joint tumor society
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• v.17 no.1
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• pp.36-43
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• 2011

Purpose: This study was designed to verify intermediate-term functional and radiological results of limb salvage operation using endoprosthetic replacement system ($MUTARS^{(R)}$) used in patients with a malignant bone tumor. Materials and Methods: Thirty one cases which used $MUTARS^{(R)}$ tumor prosthesis were reviewed. The mean age of the patients was 49.2 years and the mean follow up was 39.8 months. We retrospectively reviewed complications, and evaluated functionally and radiologically by Enneking functional score, ISOLS radiological implants evaluation system at last follow-up. Results: 3 patients had died of disease, distant metastasis was seen in 4 patients and local recurrence was seen in 1 patients. Complications were developed in 12 patients. (infection 6, leg length discrepancy 2, aseptic loosening 2, periprosthetic femoral fracture 1, screw loosening 1) Mean value of total functional scores were 81.2% in proximal femur, 77.4% in distal femur, 78.1% in proximal tibia, and 80.2% in proximal humerus. The overall radiological result was relatively satisfactory. Conclusion: Our results suggest limb salvage with the $MUTARS^{(R)}$ endoprosthesis is successful with good functional and radiological results. But we should be careful with complications such as infection.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.3
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• pp.295-313
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• 2006

Statement of problem. Higher fracture rates were reported for Branemark implants placed in the maxilla and for 3.75 mm diameter implants installed in the posterior region. Purpose. The purpose of this study was to investigate the fracture of a fixture by finite element analysis and to compare different diameter of fixtures according to the level of alveolar bone resorption. Material and Methods. The single implant and prosthesis was modeled in accordance with the geometric designs for the 3i implant systems. Models were processed by the software programs HyperMesh and ANSA. Three-dimensional finite element models were developed for; (1) a regular titanium implant 3.75 mm in diameter and 13 mm in length (2) a regular titanium implant 4.0 mm in diameter and 13 mm in length (3) a wide titanium implant 5.0 mm in diameter and 13 mm in length each with a cementation type abutment and titanium alloy screw. The abutment screws were subjected to a tightening torque of 30 Ncm. The amount of preload was hypothesized as 650 N, and round and flat type prostheses were 12 mm in diameter, 9 mm in height were loaded to 600 N. Four loading offset points (0, 2, 4, and 6 mm from the center of the implants) were evaluated. To evaluate fixture fracture by alveolar bone resorption, we investigated the stress distribution of the fixtures according to different alveola. bone loss levels (0, 1.5, 3.5, and 5.0 mm of alveolar bone loss). Using these 12 models (four degrees of bone loss and three implant diameters), the effects of load-ing offset, the effect of alveolar bone resorption and the size of fixtures were evaluated. The PAM-CRASH 2G simulation software was used for analysis of stress. The PAM-VIEW and HyperView programs were used for post processing. Results. The results from our experiment are as follows: 1. Preload maintains implant-abutment joint stability within a limited offset point against occlusal force. 2. Von Mises stress of the implant, abutment screw, abutment, and bone was decreased with in-creasing of the implant diameter. 3. With severe advancing of alveolar bone resorption, fracture of the 3.75 and the 4.0 mm diameter implant was possible. 4. With increasing of bending stress by loading offset, fracture of the abutment screw was possible.

• The Journal of Korean Academy of Prosthodontics
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• v.39 no.5
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• pp.526-546
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• 2001

Fiber-reinforced composite(FRC) was developed as a structural component for dental appliances such as prosthodontic framework. FRC provides the potential for fabrication of a metal-free, excellent esthetic prostheses. It has demonstrated success as a result of its simple fabrication, natural colour, and marginal integrity, and fracture resistance of veneering composite resin and the FRC material. Although it has lots of merits, clinical and objective data are insufficient. The purpose of this study was to evaluate the fracture strength and the marginal fitness of fiber reinforced composite bridge in the posterior region for clinical application. Sixteen bridges of each group. $Targis/Vectris^{(R)}$, $Sculpture-Fibrekor^{(R)}$, and In-Ceram, were fabricated. All specimens were cemented with Panavia 21 to the master dies. Strength evaluation was accomplished by a universal testing machine (Instron). The marginal fitness was measured by using the stereoscope (${\times}50$). The results were as follows. : 1. The fracture strength according to the materials was significantly decreased in order In-Ceram($238.81{\pm}82$), Targis Vectris($176.25{\pm}18.93$), Sculpture-Fibrekor($120.35{\pm}20.08$) bridges. 2. FRC resin bridges were not completely fractured, while In-Ceram bridges were completely fractured in the pontic joint. 3. The marginal accuracy was significantly decreased in order Targis/Vectris ($60.71{\mu}m$), Sculpture-Fibrekor($73.10{\mu}m$) In-ceram Bridge ($83.81{\mu}m$). 4. The fitness of occlusal sites had a lower value than the marginal sites(P<0.001), and the marginal gaps of inner site of the pontic were greater than that of outer sites of the pontic. Fiber reinforced composite bridges are new, esthetic prosthesis and can be clinically used in anterior regions and short span bridges. However, caution must be exercised when extrapolating laboratory data to the clinical situation because there are no long term clinical data regarding the overall success of the FRC.

• Journal of Technologic Dentistry
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• v.34 no.3
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• pp.303-314
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• 2012

Purpose: This study aimed to find overseas workplace and improve global competence through the preference survey on overseas employment by dental technology students. Methods: The survey sample consisted of 250 randomly selected dental technology students. Survey was conducted from March 1 to May 1 in 2012. Total of 245(98.0%) replies and analyzed 236 questionnaires excluding 9 incomplete questionnaires. The questionnaires used in this study consisted of 7 items for general information, overseas employment characteristics of 10 items, 7 items for overseas employment activation plane and job competency development of 7 items. Collected data were analyzed using SPSS(Statistical Package for Social Sciences) Win 19.0 statistics program. Results: Regarding general characteristics of the subjects, there were 131 third graders(55.5%), 63 first graders(26.7%) and 42 second graders(17.8%) among 130 males(55.1%) and 106 females(44.9%). 221(93.6%) of the subjects had no experience in language training. Students who had clinical training for 1-5 months were 123(52.1%), and 24(10.2%) students had more than six months. 89(37.7%) of the subjects had no clinical training. 155(65.7%) of the subjects hope to work with korean owner, and 81(34.3%) chose foreign owner. Favored working countries were Australia(41.5%), the United States(29.2%), Canada(18.2%) and other(11.0%). The field of dental ceramic was indicated to be the highest proportion of 104(44.1%). Period of training were 3 hours(40.3%) and 6 hours(35.2%). The most important training were language-centered education(54.2%), Job-oriented education(24.2%), local culture education(16.1%), other(3.0%) and Leadership Training(2.5%). The subjects chose overseas worker(44.9%), working-level practitioner (28.8%), successfully employed dental technology graduate(19.5%a) and professor(3.4%) as an instructor. The subjects get education and training information from professor(40.3%), other(28.0%), senior(14.4%), job site(8.9%) and acquaintance(8.5%). A credit exchange(2.46 points), a joint degree program(2.46 points), and a foreign professor(2.33 points) were needed to activate the overseas employment. A kind of dental prosthesis(3.58 points), carving tooth morphology(3.38 points), and majors of dental technology(3.30 points) were indicated to develop job competency for overseas employment. Age, year, clinical training experience and company owner were statistically meaningful data among the general characteristics affecting job competency development. Conclusion: The college needs to offer variety programs such as foreign language-centered education and a local job competency development program to graduates to be connected with international workplace and employment.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.7 no.1
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• pp.39-44
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• 2014

The patellar clunk syndrome is one of the patellofemoral complication, caused by formation of the fibrous nodule at the suprapatellar region after total knee arthroplasty. The symptom involves painful catching, crepitus and clunk during knee extension. It has been mainly but not exclusively associated with the posterior stabilized total knee system. The fibrous nodule is entrapped in the femoral intercondylar notch of the femoral component during flexion and as the knee is extended, it displaces back to the trochlear groove abruptly and the typical symptoms occur. The risk of developing this complication is primarily related to the design of the femoral component and higher incidence was noted with earlier designs of posterior stabilized knee prosthesis. Modifications have been made to the femoral component to optimize the kinematics of the patellofemoral joint and thereby reduced the incidence of patellar clunk syndrome but did not eliminate the problem completely. Clinical examination is the gold standard of diagnosis and imaging study has been used as a possible adjunct to diagnosis. Especially ultrasonography is an imaging modality, which can be easily performed to detect the fibrous nodule on the quadriceps tendon. We report a case of patellar clunk syndrome which was diagnosed with ultrasonography.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.439-447
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• 2019

The distance between the natural teeth and the implants is an important factor in preserving the periodontal tissues and esthetics. And abnormal positional displacement and tilting of the teeth during restorative procedure may require intentional root canal treatment and may affect masticatory function. This report is to present a successful full mouth rehabilitation of a patient with uneven dentition and collapsed occlusion using orthodontic and implant treatment. The patient had no symptoms or discomfort of temporomandibular joint disorder such as pain or sound. The orthodontic treatment was continued until implant provisional prosthesis delivery. And the vertical height of occlusion was elevated 2mm on anterior basis for anterior teeth protection and esthetics. After the orthodontic treatment, the implant abutments and natural teeth were finally restored with porcelain-fused-to-metal crowns and bridges. Satisfactory function and esthetic outcomes are observed after 6months of follow up.

• The Journal of the Korean bone and joint tumor society
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• v.16 no.1
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• pp.1-7
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• 2010

Purpose: With advances in various treatment modalities, limb salvage surgery has been commonly used in osteosarcoma of extremities. An alternative method for skeletal reconstruction is reimplantation of the tumor bearing bone following extracorporeal irradiation (ECI). We report the long-term results of ECI autograft in aspect of the oncological and functional outcomes, and complications. Materials and Methods: We retrospectively reviewed 31 osteosarcoma patients who underwent reconstruction with ECI between July 1995 and January 2006. There were 24 males and 7 females with a mean age of 24 (7-74 years) and a mean follow-up of 117 months (17-177 months). Twenty-five cases were reconstructed with ECI autograft, 6 cases with ECI autograft-prosthesis composite. The pathologic subtypes were conventional in 29 cases, periosteal in 1 case, and parosteal in 1 case. The most common location of tumor was distal femur (15 cases) followed by humerus (3), proximal fibula (3) and proximal tibia (3). Musculoskeletal Tumor Society (MSTS) score was used for functional evaluation. The overall survival rate, local recurrence, complications were analyzed. Results: The overall survival rate was 80.6% and the disease-free survival rate was 64.5%. Five patients died of distant metastasis. One patient required above-knee amputation due to local recurrence. All of them, twenty-three complications occurred, which included nonunion in 7 cases, deep infection in 5 cases, joint instability in 4 cases, metal failure in 2 cases, Limb-length discrepancy (LLD) in 2 cases, periprosthetic fracture in 1 case, epiphyseal collapse in 1, local recurrence in 1 case. The mean MSTS functional score was 62.5%. Conclusion: Extracorporeal irradiated autograft can be achieved relatively good result in aspect of oncological and functional aspect, but is needed to be additional research about occurring many complications. The reconstruction with ECI after intercalary or fragmentary resection is effective reconstruction in aspect of oncological and functional result, complications.

• Journal of the Korean Orthopaedic Association
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• v.53 no.6
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• pp.498-504
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• 2018

Purpose: To evaluate the clinical and radiological outcomes, and the complications of unicompartmental knee arthroplasty (UKA) using a fixed bearing prosthesis after 5-year follow-up. Materials and Methods: Twenty-six knees (25 patients) that underwent fixed bearing UKA between May 2003 and August 2011 were included. The subjects were 3 males (3 knees) and 22 females (23 knees), and the average age was 63.5 years. The preoperative diagnosis was osteoarthritis (23 knees) and osteonecrosis (3 knees). The mean follow-up duration was 67 months (from 60 to 149 months). The clinical evaluation included pre- and postoperative American knee society knee and function score, and range of motion. The radiology evaluation included standing antero-posterior, lateral view, and fluoroscopic film to analyze the postoperative alignment and osteolysis. Results: The mean American Knee Society knee score and function score were improved from 42.0 and 57.5 to 87.9 and 85.0, respectively (p<0.001). The mean preoperative and postoperative range of motion was $132.9^{\circ}$ and $132.5^{\circ}$, respectively. The mean femorotibial angle were varus $0.5^{\circ}$ preoperatively and valgus $2.2^{\circ}$ postoperatively. A radiolucent line was observed in 2 knees; one knee had a stable implant, while in the other knee, patellofemoral arthritis was identified during UKA. Diffuse pain of the knee joint with tenderness of the medial joint line was identified at the follow-up, so conversion to total knee arthroplasty was recommended. No other complications, such as osteolysis, infections, postoperative stiffness, and dislocation, were encountered. Conclusion: The midterm results of fixed bearing UKA were clinically and radiologically satisfactory.