Purpose: The purpose of this study was to evaluate whether three-dimensional (3D)-printed flexible denture resin has suitable mechanical properties for use as a thermoplastic denture base resin material. Materials and Methods: A total of 96 specimens were prepared using the 3D printed flexible denture resin (Flexible Denture). Specimens were designed in CAD software (Tinkercad) and printed through a digital light-processing 3D printer (Asiga MAX UV). Post-polymerization process was conducted according to air exposure or glycerin immersion at 35°C or 60°C and for 30 or 60 minutes. The maximum flexural strength, elastic modulus, 0.2% offset yield strength, and Vickers hardness of 3D-printed flexible denture resin were assessed.Result: The maximum flexural strength ranged from 64.46±2.03 to 84.25±4.32 MPa, the 0.2% offset yield strength ranged from 35.28±1.05 to 46.13±2.33 MPa, the elastic modulus ranged from 1,764.70±64.66 to 2,179.16±140.01 MPa, and the Vickers hardness ranged from 7.01±0.40 to 11.45±0.69 kg/mm2 . Conclusion Within the limits of the present study, the maximum flexural strength, 0.2% offset yield strength, elastic modulus, and Vickers hardness are sufficient for clinical use under the post-polymerization conditions of 60°C at 60 minutes with or without glycerin precipitation.

PURPOSE: To evaluate the clinical and radiological results of an opening wedge osteotomy for an osteoarthritic knee, and compared these results with those of a closing wedge osteotomy. MATERIALS AND METHODS: The study included 27 patients (29 cases) with an opening wedge osteotomy (Group A) and 30 patients (30 cases) with a closing wedge osteotomy (Group B). The radiological results obtained regarding the degree of osteoarthritis, femur-tibia angle, tibial alignment, posterior tibial slope and patellar height using the Insall-Salvati's method were analyzed. HSS score was used for evaluation of the clinical results. RESULTS: Preoperatively, there were no significant differences between the two groups regarding the degree of osteoarthritis, the femur-tibia angle, tibial alignment, posterior tibial slope, and patellar height. Two years after surgery, the femur-tibia angle and tibial alignment were significantly improved to 7.7degrees valgus and 1.3degrees valgus, respectively, and the patellar height was not changed significantly in group A. Similar degrees RESULTs were obtained in group B. The tibial posterior slope increased from 3degrees to 10.7degrees in group A and decreased from 4degrees to 3.7degrees in group B. Clinically, the HSS score was improved from 74 points preoperatively to 93 points 2 years postoperatively in the opening group, and was similar to the improvement observed in the closing group. The complications included 1 delayed union in the opening group, and 3 cases of superficial peroneal nerve palsy and 1 delayed union in the closing group. CONCLUSION: An opening wedge osteotomy is a relatively simple and safe procedure that gives similar radiological and clinical outcomes to a closing wedge osteotomy, without peroneal nerve palsy. However, surgeons should take care in preventing an increase in the tibial posterior slope.
Humans ; Knee ; Osteoarthritis ; Osteotomy* ; Paralysis ; Peroneal Nerve

OBJECTIVE: To investigate the effect of slow walking speed on the gait. METHOD: Twenty healthy young male subjects were recruited. The temporospatial data, kinematic and kinetic data in sagittal plane at two different walking speed (2 km/hr, 4 km/hr) were obtained through three dimensional analyzer with the force plate, and compared these parameters at slow gait speed to those at normal gait speed. RESULTS: The cadence and step length decreased significantly and double support time increased significantly (p<0.05) at slow speed compared to at normal speed. The most peak angle of hip, knee and ankle joint decreased, maximal ankle dorsiflexion angle in stance phase increased significantly at slow speed compared to at normal speed (p<0.05). The most maximal extension and flexion moment and power in sagittal plane decreased compared to at normal speed (p<0.05). CONCLUSION: The results of this study demonstrate that only slow walking speed without any pathology may change the temporospatial, kinematic and kinetic parameters of gait, and these results may be useful to interpret the data of gait analysis in the disabled persons with slow walking speed.
Ankle ; Ankle Joint ; Disabled Persons ; Gait* ; Hip ; Humans ; Knee ; Male ; Pathology ; Walking*

PURPOSE: This study aimed at evaluating the pattern of changes in estrogen receptor (ER), progesterone receptor (PR) and the HER2 expression in primary and recurrent breast cancer. METHODS: In the study, we analyzed the changes of the ER and PR and the HER2 immunohistochemical expression to identify the patterns of changes and the predictive factors for the changes in 153 patients with primary and recurrent breast cancer between 1991 and 2005. RESULTS: There was a significant decrease in the positive rate of ER (50.3% to 38.6%, p<0.001), PR (43.8% to 26.8%, p=0.0095) and the HER2 (40.3% to 36.3%, p<0.001) expression in the primary breast cancers and recurrent breast cancers. The rate of triple negativity (ER/PR/HER2: all negative) was increased from 25.8% to 43.5% (p<0.001). Among 44 (28.6%) patients with changes in ER and ER status changed from positive to negative in 31 patients (20.3%) and negative to positive in 13 patients (8.3%) (p=0.007). For 58 patients (37.9%) who showed a change of the PR, the PR status changed from positive to negative in 42 patients (27.5%) and vice versa in 16 patients (10.4%) (p=0.0006). Twenty one patients (16.9%) changed from HER2 positive to HER2 negative and vice versa in 9 patients (7.3%) (p=0.029) among the 30 patients (24.2%) with changes in the HER2 expression. A multivariate analysis indicated that hormonal therapy was a significant factor that had an influence on the ER (odds ratio, 4.4) and PR (odds ratio, 2.6) changes. There were no significant differences in the survival rates according to the changes of the ER and PR, and the HER2 expression. CONCLUSION: The more common changes from positive to negative among the ER, PR, and HER2 indicated poor tumor biology of recurrent tumor. Therefore, the assessment of the ER, PR, and HER2 statuses is important for effectively treating recurrent breast cancer and especially those who have a previous history of hormonal therapy although survival benefit was not observed in this study.
Biology ; Breast ; Breast Neoplasms ; Estrogens ; Humans ; Multivariate Analysis ; Receptors, Progesterone ; Recurrence ; Survival Rate

Purpose: Various incision techniques have been used in breast-conserving surgery (BCS) to reduce scar formation, including the frequently used periareolar incision technique. However, its applicability in removing large-size tumors or those distant from the nipple has remained limited. We performed periareolar zigzag (P-Z) incision to address these problems in BCS and to improve cosmetic outcomes. Methods: Patients who underwent P-Z incision in BCS between January 2016 and November 2017 were retrospectively analyzed in terms of clinicopathological features and surgical findings. Factors affecting the positive margin were analyzed. Results: A total of 305 patients were reviewed. The patients presented with a median age of 51 years, mean tumor size 1.9 cm, and mean tumor distance of 3.3 cm from the nipple. Intraoperative frozen biopsy and final pathologic findings showed 43 (14.1%) and 7 (2.3%) tumor-positive margins. There were no major complications associated with the surgery, and no re-operations were required due to bleeding or other reasons. Conclusion The P-Z incision technique was used to achieve sufficient operative field during BCS, and large tumors or those distant from the nipple could be removed without any complications. This technique is considered an oncologically safe surgical technique resulting in good cosmetic outcomes.

PURPOSE: This study sought to determine the 1-year clinical effectiveness and safety of a biodegradable, polymer-containing Biolimus A9™-eluting stent (BES) in Korean patients with acute coronary syndrome (ACS). MATERIALS AND METHODS: A total of 1000 ACS patients with 1251 lesions who underwent implantation of BESs at 22 centers in Korea were enrolled between May 2011 and July 2013. We assessed major adverse cardiac events (MACE) defined as the composite of cardiac death, non-fatal myocardial infarction (MI), and clinical-driven target vessel revascularization at 12 months. RESULTS: Patient mean age was 62.6±11.4 years. 72.8% of the patients were male, 28.5% had diabetes, 32.8% had multi-vessel disease (MVD), and 47.9% presented with acute MI (AMI). The mean global registry of acute coronary events risk score of all patients was 103.0±27.6. The number of stents per patient was 1.3±0.6. The incidences of MACE and definite stent thrombosis at 12 months were 3.9% and 0.2%, respectively. On multivariate Cox-regression analysis, age ≥65 years was identified as an independent predictors of 1-year MACE (hazard ratio=2.474; 95% confidence interval=1.202−5.091). Subgroup analyses revealed no significant differences in the incidence of MACE between patients with and without diabetes (4.3% vs. 3.7%, p=0.667), between those who presented with and without AMI (4.4% vs. 3.4%, p=0.403), and between those with and without MVD (4.6% vs. 3.5%, p=0.387). CONCLUSION: Our study demonstrated excellent 1-year clinical outcomes of BES implantation in patients at low-risk for ACS.
Acute Coronary Syndrome/drug therapy ; Aged ; Drug-Eluting Stents/adverse effects ; Female ; Humans ; Incidence ; Kaplan-Meier Estimate ; Male ; Middle Aged ; Multivariate Analysis ; Proportional Hazards Models ; Republic of Korea ; Sirolimus/adverse effects ; Sirolimus/analogs & derivatives ; Sirolimus/therapeutic use ; Time Factors ; Treatment Outcome