• The Journal of Korean Academy of Prosthodontics
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• v.49 no.3
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• pp.254-262
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• 2011

Purpose: This study aims to evaluate and prospect for current research trend and developmental perspectives via analyzing recent biomaterial coated-implants study. Materials and methods: To investigate each subject respectively, several biomaterials that are using for implant surface coating were set as 'keywords'. By these keywords, major research groups in each subject were chosen, and research trend of them was analyzed. Trend of In vivo studies that examined selected biomaterials were analyzed to evaluate commercial potential. Results: The collagen research accounted for 40% of total implant study, which was the highest, and fibronectin, BMPs (bone morphogenetic proteins) and RGD (Arg-Gly-Asp) peptides followed, which were ranked in descending order. Furthermore, figures of all four research subjects were also increased with time, especially a sharp increase in RGD research. According to the results of major research group, collagen that was combined with other organic and inorganic biomaterials was mostly examined, rather than using collagen only. Major research groups investigating BMPs mostly focused on rhBMP-2. In animal studies, collagen was used as resorbable membrane in guided bone regeneration (GBR) or drug carrier, while BMPs were used with bone graft materials or coating material for titanium implant surface. Conclusion: There is not consistency of results even in identical subjects research field. Many studies are ongoing to optimize combination between mechanical surface treatment and biomaterials such as extracellular matrix component and growth factors.

• Journal of Korean Orthopaedic Sports Medicine
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• v.8 no.2
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• pp.102-108
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• 2009

Purpose: The purpose of this study is to report a result of the technique that reconstruct posterior cruciate ligament (PCL) and posterolateral corner (PLC) simultaneously using a fresh-frozen Achilles tendon allograft. Materials and Methods: Forty two patients (45 legs) underwent PCL and PLC reconstruction were included. There were 38 males and 4 females. Mean age was 39 years. Used graft was a fresh frozen Achilles tendon allograft, which was divided by two size, larger one (${\emptyset}$ 10 mm) for PCL reconstruction and smaller one (${\emptyset}$ 8 mm) for PLC reconstruction. Arthroscopic reconstruction of the PCL was performed using transtibial, single incision, and single bundle technique with 10mm fresh frozen Achilles allograft tendon first. After PCL reconstruction, reconstruction procedure for posterolateral instability was performed using modified figure of "8" technique using smaller gtaft. For clinical evaluation, range of motion, posterior drawer test, varus stress test, prone external rotation (dial) test, Lysholm score, Tegner activity scale and posterior stress radiograph were used. Mean follow up period was 25 months. Results: Preoperatively posterior drawer test was 5 cases in grade II and 40 cases in grade III posterior instability. At final follow-up 22 cases returned within normal condition, 18 cases grade I and 5 cases grade II posterior instability. Though all patients showed positive result over 10 degrees in dial and varus stress test preoperatively, but only 9 cases showed positive both test at final follow-up. The range of motion deficit over $10^{\circ}$ flexion was 3 cases. Lysholm score was improved from mean 50 preoperatively to mean 83(p<0.05) and Tegner activity scale improved from mean 2.1 preoperatively to mean 4.6(p<0.05). In posterior stress radiographs, posterior displacement was improve from mean 16mm preoperatively to 4.1mm after treatment(p<0.05). All patients had improved compared to their pre-operative status as measured by physical examination such as posterior drawer test, varus stress test, dial test. Conclusion: We had successful results by combined reconstruction of the PCL & PLC with a fresh frozen Achilles tendon allograft in patients with PCL and posterolateral rotatory instability at a time.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.2
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• pp.82-89
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• 2014

Purpose: The purpose of this study was to observe the change of viscoelastic properties of dental resin cements during polymerization. Materials and methods: Six commercially available resin cement materials (Clearfil SA luting, Panavia F 2.0, Zirconite, Variolink N, RelyX Unicem clicker, RelyX U200) were investigated in this study. A dynamic oscillation-time sweep test was performed with AR1500 stress controlled rheometer at $32^{\circ}C$. The changes in shear storage modulus (G'), shear loss modulus (G"), loss tangent (tan ${\delta}$) and displacement were measured for twenty minutes and repeated three times for each material. The data were analyzed using one-way ANOVA and Tukey's post hoc test (${\alpha}$=0.05). Results: After mixing, all materials demonstrated an increase in G' with time, reaching the plateau in the end. RelyX U200 demonstrated the highest G' value, while RelyX Unicem (clicker type) and Variolink N demonstrated the lowest G' value at the end of experimental time. Tan ${\delta}$was maintained at some level and reached the zero at the starting point where G' began to increase. The tan ${\delta}$and displacement of the tested materials showed similar pattern in the graph within change of time. The displacement of all 6 materials approached to zero within 6 minutes. Conclusion: Compared to other resin cements used in this study, RelyX U200 maintained plastic property for a longer period of time. When it completed the curing process, RelyX U200 had the highest stiffness. It is convenient for clinicians to cement multiple units of dental prostheses simultaneously.

• Journal of the Korean Arthroscopy Society
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• v.13 no.1
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• pp.46-52
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• 2009

Purpose: To evaluate the usefulness of minimally invasive arthroscopy-assisted plate removal of a laterally inserted periarticular distal femur plate used for the treatment of AO type-C distal femur fractures. Materials and Methods: From October 2002 to November 2005, we evaluated 17 patients whose plates were removed through minimally invasive arthroscopy-assisted plate-removal technique and 15 patients who got their plates removed through conventional method without using arthroscopy, 32 patients in total. All these patients included in this study initially underwent open reduction and internal fixation of the distal femoral fractures with a lateral plate, and complained of continued pain over the lateral femoral condyle after the fracture fixation. The average age was 42.6 (ranges: 20~66) and initial fracture types included 16 cases of C1, 11 cases of C2, and 5 cases of C3 following AO/ASIF classification guidelines. Measured outcomes included: associated intra-articular pathologies, time needed to return to activities of daily living, patients' overall satisfaction, complications following the removal of hardware, and pain before and 6 months after the operation. Results: The distal-most end of the plate was placed in the knee joint in all cases and damage of the lateral articular capsule was found in 23 cases. Continuous wound discharge after surgery was found in one case who underwent arthroscopy-assisted plate removal, and it was treated by irrigation and re-suture. Average time needed to return to activities of daily living was 7 days in arthroscopy assisted group and 7.6 days in conventionally removed group. Fourteen patients (82.4%) who underwent arthroscopyassisted plate-removal reported above 'fair' satisfaction and the Visual analog scale pain score decreased from 4.9 to 1.9, six months after the plate removal. Thirteen patients(86.7%) who underwent conventional plate removal reported above 'fair' satisfaction and the Visual analog scale pain score decreased from 5.2 to 2.5, six months after the operation. Conclusion: Through minimally invasive arthroscopic-assisted plate removal, intrarticular pathology of the knee joint was able to be simultaneously identified and treated at the time of hardware removal. Damage of lateral capsule of the knee joint caused by the inserted plate for the treatment of type C distal femoral fracture was very frequently found and following the plate removal, patients experienced an improvement in pain score. We therefore recommend routine lateral distal femoral plate removal if the bony union is attained in such cases as type C distal femoral fractures whose distal most end of the plates are located in the joint.

• Journal of radiological science and technology
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• v.40 no.1
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• pp.109-120
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• 2017

In order to examine how Radiological Technologists perceive the oriental doctor's use of Medical Imaging Equipment, surveys were conducted for the members of the Korean Radiological Technologists Association. The total number of respondents were 515 and 481, with 34 insincere responses removed caused of nonvalidated answer. The results of the analysis are as follows. Although there were no statistical significance in the difference in perception by location of residence, work place, and educational background, respondents with higher education showed a tendency to agree on the use of comprehensive medical imaging equipment, but tended to oppose the use of special medical imaging equipment. Differences in perception by gender showed a greater negative perception toward the oriental doctor's use of medical imaging equipment by women than men. In particular, women showed more negative tendency for oriental doctor's use of special medical imaging equipment such as MRI, CT, and ultrasound equipment compared to men, and this was statistically significant. The difference in perception by age showed that the oriental doctor's use of medical imaging equipment was negative in the 20~30s, neutral in the 40~50s, and positive in the 60s, which were statistically significant. The difference in perception by work experience showed that the longer the work experience was, the more positive it was toward oriental doctor's use of medical imaging equipment. Specifically, the most favorable tendency was found with work experience of more than 30 years, which was statistically significant. The results of this study revealed the Radiological Technologists' perceptions on the oriental doctor's use of Medical Imaging Equipment and this can contribute to the direction of public health promotion in the future.

• Journal of the Korean Society of Radiology
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• v.8 no.5
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• pp.241-248
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• 2014

The purpose of this study were to analyze the clinical correlation between the thyroid autoimmune antibodies (anti-TPO Ab, anti-TG Ab, and TSH) and the maximum standardized uptake value ($SUV_{max}$) base on the Hashimoto's thyroiditis and the Graves' disease in diffusely $^{18}F-FDG$ uptake of the thyroid gland to the PET/CT image. To achieve this, we was performed the PET/CT examination for the 1,097 subjects from May 2010 to April 2013 in the health screening, and was detected the diffused FDG thyroid uptake, and was additionally performed the thyroid function test (TFT) and the ultrasound (US). As a results, the autoimmune thyroid disease with the diffused FDG thyroid uptake were discovered 39 patients (3.9%), of this, the Hashimoto's thyroiditis was 43.6% and the Graves' disease was 23.1%. Hashimoto's thyroiditis was shown the positive reaction of high titer between the anti-TPO Ab and the anti-TG Ab level, and the correlation coefficient between the $SUV_{max}$ and the anti-TPO Ab was a statistically significant (r>04, p<0.05). Also, Graves' disease was shown the positive reaction of high titer most of the thyroid autoimmune antibodies, and the correlation coefficient between the $SUV_{max}$ and the anti-TPO Ab was a statistically significant (r>05, p<0.01). Therefor, when have a high standard of the $SUV_{max}$ due to the diffusely $^{18}F-FDG$ uptake of the thyroid gland, Hashimoto's thyroiditis and Graves' disease were proportionally increased the anti-TPO Ab and TSH level, respectively. The correlation coefficient between the $SUV_{max}$ and the thyroid autoimmune antibodies will be the most influential criterion that was a standard of judgment for the epihpenomenon of the autoimmune thyroid disease, and it will be available for the clinical application.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.4
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• pp.325-329
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• 2015

Purpose: The aim of this study was to compare the film thicknesses of several resin cements as a function of time after mixing and to examine the effect of working time on the film thicknesses. Materials and methods: The film thickness (${\mu}m$) of 4 resin cements (n=10), 1 composite resin (Panavia F 2.0), 3 self-adhesive resin (Clearfil SA luting, Zirconite, RelyX U200) cements was measured at 20-second intervals after mixing of the cements up to 200 seconds under a load of 50 N. Linear regression was fitted to verify the effect of working time on the film thickness of each cement. Data were compared to the working time recommended by manufacturers using Wilcoxon test ($\alpha$=.05). Results: All of the materials showed a positive linear correlation between the film thickness and working time. There was no statistically significant difference between the working time based on our results and the values recommended by the manufacturers even though there was a discrepancy between those two values. Conclusion: The film thickness of resin cements could increase with the increase of working time. Working time to meet the ISO standard of $50-{\mu}m$ maximum film thickness could be different from the manufacturer's recommended value.

• Journal of the Korean Orthopaedic Association
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• v.54 no.3
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• pp.244-253
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• 2019

Purpose: Total hip arthroplasty was performed using a direct anterior approach (DAA) on an ordinary operation table and a short femoral stem. The clinical radiographic results were evaluated by a comparison with those performed using the modified hardinge (anterolateral approach, ALA) method. Materials and Methods: From January 2013 to November 2015, 102 patients who underwent total hip arthroplasty using DAA (DAA group) and the same number of patients using ALA (ALA group), both performed by a single surgeon, were compared and analyzed retrospectively. The operation time and amounts of bleeding were compared, and the improvement in post-operative pain, ambulatory capacity and functional recovery of the hip joint were checked. The location of insertion of the acetabular cup and femoral stem were evaluated radiologically, and the complications that occurred in the two groups were investigated. Results: The amount of bleeding was significantly smaller in the DAA group (p=0.018). Up to 3 weeks postoperatively, recovery of hip muscle strength was significantly higher in the DAA group (flexion/extension strength p=0.023, abduction strength p=0.031). The Harris hip score was significantly better in the DAA group for up to 3 months (p<0.001) and the Koval score showed significantly better results in the DAA group up to 6 weeks (p≤0.001). The visual analogue scale score improvement was significantly higher in the DAA group by day 7 (p=0.035). The inclination angle (p<0.001) and anteversion angle (p<0.001) of the acetabular cup were located in the safe zone of the DAA group more than in the ALA group, and there was no statistically significant difference in the position of the femur stem and leg length difference. During surgery, two cases of greater trochanter fracture occurred in the DAA group (p=0.155). Conclusion: The DAA performed in the ordinary operation table using a short femoral stem showed post-operative early functional recovery. Because a simple to use fluoroscope was used during surgery with an anatomical position familiar to the surgeon, it is considered to be useful for the insertion of implants into the desired position and for an approach that is useful for the prevention of leg length differences.

• Journal of the Korean Society of Radiology
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• v.84 no.5
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• pp.1123-1133
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• 2023

Purpose Our study aimed to evaluate the association between automated quantified body composition on CT and pulmonary function or quantitative lung features in patients with chronic obstructive pulmonary disease (COPD). Materials and Methods A total of 290 patients with COPD were enrolled in this study. The volume of muscle and subcutaneous fat, area of muscle and subcutaneous fat at T12, and bone attenuation at T12 were obtained from chest CT using a deep learning-based body segmentation algorithm. Parametric response mapping-derived emphysema (PRM^emph), PRM-derived functional small airway disease (PRM^fSAD), and airway wall thickness (AWT)-Pi10 were quantitatively assessed. The association between body composition and outcomes was evaluated using Pearson's correlation analysis. Results The volume and area of muscle and subcutaneous fat were negatively associated with PRM^emph and PRM^fSAD (p < 0.05). Bone density at T12 was negatively associated with PRM^emph (r = -0.1828, p = 0.002). The volume and area of subcutaneous fat and bone density at T12 were positively correlated with AWT-Pi10 (r = 0.1287, p = 0.030; r = 0.1668, p = 0.005; r = 0.1279, p = 0.031). However, muscle volume was negatively correlated with the AWT-Pi10 (r = -0.1966, p = 0.001). Muscle volume was significantly associated with pulmonary function (p < 0.001). Conclusion Body composition, automatically assessed using chest CT, is associated with the phenotype and severity of COPD.

• Journal of Chest Surgery
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• v.43 no.6
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• pp.710-715
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• 2010

Background: Video-assisted thoracic surgery (VATS) became common in the treatment of spontaneous pneumothorax (SP). Therefor we've reviewed the recurrence rate after VATS and analysed the factors affecting recurrent pneumothorax after VATS on this study. Material and Method: This retrospective analysis was performed on 321 patients of SP who had undergone VATS from Jan. 2001 to Dec. 2008. The two groups were divided as follow: group A, non-recurrent group (298 patients: 93%); and group B, recurrent group (26 patients: 7%); the two groups were analysed retrospectively. Result: The average age of the study groups were $20.9{\pm}4.3$ years old in recurrent group vs. $25.9{\pm}11.7$ years old in non-recurrent group with statistical significance (p < 0.05). There were no statistical significance in male to female ratio, height/weight ratio, location of pneumothorax, smoking history, operative time, duration of drain, hospital stay, indication of opertion and incidence rate. Average length of duration in recurrence was 12.9 months. There was 22 (95.7%) recurrent patients after VATS within 4 year period among recurrent group. Treatment methods in 23 of recurrent patients were, 8 (VATS), 2 (Axillary thoracotomy) with 15% or more in amount of pneumothorax and 7 (7 Fr. chest tube), 6 (nasal 02) with 15% or less in amount of pneumothorax. Among 10 cases of reoperation, there were 3 cases of over looking type and 7 cases of new growing type. There was no additional recurrence after these procedures were given. Conclusion: There was higher recurrence rate in younger age after VATS thus for those under 20 yrs old, detailed and possible preoperative warning for recurrence is warranted. Most recurrence occured within 4 year period, thus for this reason, regular interval based follow up with chest x-ray study is suggested during this period.