• Journal of Biomedical Engineering Research
• /
• v.25 no.1
• /
• pp.71-76
• /
• 2004

In order to investigate the Post-operative changes in scoliotic spine according to selection of fusion level a mathematical finite element model of King-Moe type II scoliotics spine system was developed. By utilizing this finite element scoliosis model surgical correction simulation procedures of pedicle fixation and derotation were simulated. In consequence of the calculation by changing the fusion Levels, postoperative changes like Cobb angle, apical vertebrae axial rotation (AVAR), thoracic kyphosis, and rib hump were Qualitatively analyzed. In the analysis of operative kinematics, the decrease or Cobb angle was most prominent in distraction than in deroation. Applying the rod derotation only was not effective in decrease of Cobb angle but just caused increase of At AR and rib hump. From the operative simulation, co-action or distraction and translation during rod insertion has major impact on Cobb angle decrease and maintenance of kyphosis. With rod rotation, Cobb angle decrease was obtained, but combined increase of AVAR and rib hump was simulation observed as well. The case of most extended instrumentation range with 60o rod rotation produced double decrease of Cobb angle, but the increase of rib hump and AYAR occurred corresponding1y. The optimum selection of fusion level was proved as one level less than inflection position of the thoracic spine curvature.

• Journal of Distribution Science
• /
• v.13 no.12
• /
• pp.85-94
• /
• 2015

Purpose - The purpose of this paper is to provide a political registration point for analyzing the economic impacts on the national economy from the REITs distribution industry in our country. The REITs distribution industry was introduced in 2001 to accelerate the corporate restructuring process and advance the real estate market. During its establishment, the REITs distribution industry faced difficulties; however, the industry grew rapidly through interest from institutional investors, thus mitigating the establishment problems by 2006. In Korea, more than 108 REITs were operating as of the end of June 2015. REITs contribute significantly to the national economy. The economic impacts on the national economy of the REITs distribution industry was analyzed using input-output (I-O) analysis with respect to production, imports, value-added, and employment. Research design, data, and methodology - The research used an I-O analysis of the activities of the REITs distribution industry in the national economy. The I-O analysis methodology analyzes the economic effects that influence other industries with respect to one unit of external investment. The data for this analysis were the I-O table of 2013 as published by the Bank of Korea in 2014. Results - The findings of this study are as follows. First, if an external input to the REITs distribution industry is 1 won, the overall impact of the product is 1.3869 won, the import induction is 0.0002 won, and the value-added induction is 0.7656 won. A new investment of 659.9 billion won into the REITs industry was estimated to produce a gross effect of 915.2 billion won. Second, if an external input to the REITs distribution industry is 1 billion won, the employment-inducing effects are estimated at 19.6394 individuals. The employment-inducing coefficient of 19.6394 for the REITs distribution industry indicates that the industry created significant employment-more than other industries-because the coefficient was 2.2 times the 2013 industry average employment-inducing coefficient of 8.8. Third, the investment effects of the REITs distribution industry on production induction, value-added induction, and employment induction are assumed to be large in business support services, financing, communications and broadcasting, and professional, scientific, and technical services. Conclusions - The REITs distribution industry was analyzed as having a strong employment inducing, high value added effect. The REITs distribution industry is an excellent alternative for the government authority to create multilateral jobs. Because the REITs distribution industry has a significant positive impact on the national economy, it should be developed. However, the I-O methodology has restrictions with respect to the fixation and timing of the input coefficient. Follow-up research is expected to supplement the analysis method at a specific point in time.

• Proceedings of the Ginseng society Conference
• /
• 1998.06a
• /
• pp.322-326
• /
• 1998

In order to evaluate menopausal syndrome objectively, examinations were performed as follows: 1) Simplified Menopausal Index (SMI Koyama) and QOL questionnaire (Nagata) were examined subjectively. 2) Urine 17-KS-5 (S Nishikaze), 17-OHCS (OH) were examined objectively. 3) A mobile telemedical device with EKG and KSG was lent to Patients. The subjects were 48 menopausal patients who visited our university hospital as outpatients. According to the results of 5, OH, the subjects were divided into 4 Groups; Group I is high S & high OH, Group ll low S & low OH, Group 111 is low S & high OH, Group tl is high S & low OH. Group IH was the largest (64.6%), Group of was none. The subjects showed significantly lower QOL condition and higher score of SMI. In the QOL, questionnaire items of fixation to physical status (psychogenic reaction), sleep (insomnia), pain(chronic pain) were in common. In SMI, functional vascular symptoms were the largest number. On treatment, Group I was considered to have no need for supplementary agents, but anti-Oketsu agents was prescribed. For Group ll and in some supplementary agents such as red ginseng were prescribed, because they showed low 5. In conclusion, all the groups showed a sign- nificant improvement of QOL and SMI. Group I showed a decrease of OH, Group ll showed an increase of 5, Group In showed an increase of S and SIOH and a decrease of OH. These phenomena were considered prohomeostatic. In QOL, the items of chronic pain, insomnia and appetite were improved. In SMI, chillness, dyspnea, palpitation, pain and fatigability were improved. In mobile tole-medical device, abnormal findings were found in 88.2% of patients. General sdaptation syndrome (Selye, H.) is considered to adjust human life. Menopause is the transit period to exhausted stage in it. So its symptoms vary from person to person. In conclusion, 5 and OH are useful both for classification of menopausal syndrome and for determining treatments according to the classification

• The Journal of the Korean bone and joint tumor society
• /
• v.16 no.2
• /
• pp.80-86
• /
• 2010

Purpose: The skeleton is commonly affected by metastatic cancer. The purpose of this study was to evaluate the results of treating metastatic pathologic fractures in lower extremities using locking plates. Materials and Methods: Between 2004 and 2010, we evaluated 12 patients (13 cases) of metastatic pathologic fractures in lower extremities, treated with the locking plate. Mean patient age was 62.2 years (range, 50-81 years), the locations of the fractures were; proximal femur in 2 cases, femoral mid-shaft in 3, distal femur in 3, proximal tibia in 4, and distal tibia in 1 case. The interval to wheelchair ambulation, pain relief and complications were evaluated. Additionally, we assessed operation time and postoperative blood loss. Results: Mean time from operation to wheelchair ambulation was 3.2 days (range, 1-6 days). Mean VAS scores improved from a preoperative score of 8.1 points (range, 7-9 points) to a score of 2.7 points (range, 2-4 points) at 1 week postoperatively. No early complications associated with surgery were encountered. Mean operation time was 88.4 minutes (range, 70-105 minutes), and mean postoperative blood loss was 246.5 ml (range, 130-320 ml). Conclusion: Internal fixation of metastatic pathologic fractures using a locking plate in the lower extremity can be an effective treatment option in the meta- or diaphyseal area of long bones with massive bony destruction or poor bone stock by offering early ambulation, pain relief and low postoperative complications.

• The Journal of the Korean bone and joint tumor society
• /
• v.13 no.2
• /
• pp.96-104
• /
• 2007

Purpose: The authors investigated whether 35 flexible nail-rotating hinge composite reconstructions around knee joint minimize junctional osteolysis of host bone. Material and Method: The reconstructive technique was as follows: 1) en bloc tumor resection, 2) filling of the host bone marrow cavity with multiple Ender nails, 3) assembling the Ender nails and an Endo-Link type total knee component with wire and bone cement. Result: Mean follow-up was 53 months (ranged 30~79). At final follow-up, 29 patients retained a mobile joint. Resection of more than 40% of bone showed a positive relationship with junctional hypertrophy (p=0.028). Eight patients showed nail breakage and eight prostheses were removed due to early or late infection. The cumulative prosthetic survival rate was 33% at 6 year. Average functional score according to the MSTS criteria was 26.8. Conclusion: Mid-term evaluations showed that results were fair. The revision process was straightforward. Junctional hypertrophy observed appears to give some clues as to how to minimize osteolysis at the prosthesis-host junction after modular prosthesis fixation.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.34 no.6
• /
• pp.398-403
• /
• 2012

Purpose: Mandible resection and discontinuity defect created lead to aesthetic and functional problems. The iliac crest bone graft exhibits relative ease for bone harvesting, possibility of two team approach, ability to close the wound primarily, large amount of corticocancellous bone and relatively few complications. Whereas the use of free vascularized flaps has donor site morbidity and worse-fitting bone contour, the use of nonvascularized iliac bone graft has advantages in the operation time and patients' recovery time. So, nonvascularized iliac bone graft could be an attractive option. Methods: Twenty-one patients (M:F=1:1.1) underwent iliac crest bone harvesting for reconstruction of mandibular discontinuity defect (mean length : $61.6{\pm}17.8$ mm), from May 2005 to October 2011 at the Department of Oral and Maxillofacial Surgery in Kyungpook National University. The average age was $44.1{\pm}16.4$ years and the mean follow up periods was $28.2{\pm}22.7$ months. Bone resorption rate, according to age, sex, primary lesion, location and distance of defect, type of fixation plate, time of graft and pre-operative radiation therapy, were measured in each patient. Results: The mean bone resorption rate was $16.1{\pm}9.0%$. Bone resorption rate was significantly increased in mandibular defect that is over 6 cm in size (P=0.015, P<0.05) and the cases treated pre-operative radiation therapy (P=0.017, P<0.05). All was successfully fixed and maintained for the long-term follow-up. There were a few donor site complications and almost all patients were shown favorable outcome without severe bone resorption in this study. Conclusion: The nonvascularized iliac bone graft seems to be a reasonably reliable treatment option for reconstruction of mandibular discontinuity defects.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.37 no.4
• /
• pp.264-271
• /
• 2011

Purpose: This study evaluated retrospectively the postsurgical facial hard tissue profile of a Le Fort I osteotomy with/without posterior impaction and rigid internal fixation to correct mandibular prognathism. After observing a difference between the two groups, this measurement was used to prepare a treatment plan for 2-jaw surgery. Patients and Methods: Thirty patients who had undergone orthognathic surgery in Pusan National University Dental Hospital were enrolled in this study. Fifteen patients were treated using a Le Fort I osteotomy with posterior impaction and mandibular setback bilateral sagittal split ramus osteotomy, and the other fifteen patients were treated without posterior impaction. The preoperative (T0), immediate postoperative (T1) and six-month follow-up period (T2) cephalograms were taken and difference between T1-T0 and T2-T2 was analyzed. Results: Both groups was FH-ABp, SNB and ANB showed significant changes in the measurement, whereas only the posterior impaction group showed a change in the SN-U1, occlusal plane, posterior facial height, surgical movement difference from the L1 and B-point. There was no significant statistical change between the immediate postoperative (T1) and six-month follow-up (T2) hard tissue analysis in the two groups. Conclusion: A Le Fort I osteotomy with posterior impaction is considerable for patients with a flat occlusal plane angle, large posterior facial height, prominent B-point, pogonion and labioversed incisal inclination if the indications are well chosen.

• The Journal of Korean Academy of Prosthodontics
• /
• v.38 no.4
• /
• pp.526-543
• /
• 2000

Finite element analyses were performed to study effects on stress distribution generated in jaw bone for various shapes of dental implants: plateau type, plateau with small radius of curvature, triangular thread screw type in accordance with ISO regulations and square thread screw filleted with small radius partially. It was found that square thread screw filleted with small radius was more effective on stress distribution than other dental implants used in analyses. Additional analyses were performed on the implant with square thread screw filleted with small radius for very-ing design parameters, such as the width of thread end, the height of the thread of the implant and load direction, to determine the optimum dimensions of the implant. The highest stress concentration occurred at the region in jaw Pone adjacent to the first thread of the implant. The maximum effective stress induced by a 15 degree oblique load of 100 N was twice as high as the maximum effective stress caused by an equal amount of vertical load. Stress distribution was more effective in the case when the width of thread end and the height of thread were p/2 and 0.46p, respectively, where p is the pitch of thread. At last, using tensile force calculated from the possible insert torque without breading bone thread, finite element analysis was performed on the implant to calculate pre-stress when the primary fixation of the implant was operated in jaw bone. The maximum effective stress was 136.8 MPa which was proven to be safe.

• The Journal of Korean Academy of Prosthodontics
• /
• v.39 no.3
• /
• pp.243-249
• /
• 2001

Statement of the problem. The interest in all-ceramic restorations has increased as more techniques have become available. With the introduction of machinable dental ceramics and CAD/CAM systems or Copy-milling systems there is a need for evaluating the quality levels of these new fabrication techniques. Purpose. This study was to evaluate the fitting accuracy of machined all-ceramic crowns made out of an industrially prefabricated feldspathic porcelain. Material and Methods. Three master models with different cutting depth (0.8mm/1.0mm/1.2mm)were produced using a palladium-silver alloy. A total of 36 working dies, 12 of each form, was used for the modellation of prototype resin copings and 36 additional crowns, 12 of each cutting depth, were produced by using the $CEREC^{(R)}2$ system for all crowns. The maginal fit of all 72 crowns was then evaluated on their respective master die at 54 circularly staggered points of measurement per crown under a fixation pressure of 30 N by using a computerized video image system. Results. The medians of the copy-milled $CELAY^{(R)}$ crowns ranged from 29 to $36{\mu}m$. The highest value for the marginal gap was found in group B (cutting depth 1.0mm) at $107{\mu}m$. The median for the $CEREC^{(R)}2$ crowns was found between 43.5 and $70{\mu}m$. The maximum values for all three groups ranged from $181{\mu}m$ to $286{\mu}m$. With $286{\mu}m$ the highest value for marginal gap was found in group C. the Kruskal-Wallis test and multiple comparisons analysis procedure revealed a significant influence of the production technique on the marginal fit in all three groups (p<0,02). Conclusion. 1. The $CELAY^{(R)}$ system is capable to produce all-ceramic crowns with a significantly better marginal fit than the $CEREC^{(R)}2$ system. 2. As far as premolar crowns produced with the $CEREC^{(R)}2$ system are concerned, the cutting depth has a significant influence on fitting accuracy. 3. The production of crowns with an acceptable marginal fit is possible with both systems. However, adhesive luting is recommended for milled feldspathic porcelain crowns.

• Journal of Periodontal and Implant Science
• /
• v.34 no.3
• /
• pp.581-591
• /
• 2004

Calcium carbonate(CC) is biocompatible and gradually absorb to be replaced by bone when implanted into bone tissue. Fibrin-fibronectin sealant system (FFSS) is a product of human-derived plasma. The effect is hemostasis, tissue fixation and adhesion, We expect synergic effects of this two materials in periodontal regeneration. When FFSS was grafted with bone graft in intrabony defects, could be eliminated exofolication of bone graft materials. This study evaluated above materials for periodontal regeneration of 6mm intrabony defects in 36 patients. lap surgery was carried in 14 defects of control group. experimental group 1 was 11 defects grafted with calcium carbonate, experimental group 2 was 11 defects which were grafted with calcium carbonate with FFSS. The clinical parameters evaluated included changes in attachment level, probing depth, gingival recession at 6 months. Postsurgery probing depth reduction was 3.1 ${\pm}$ 0.9mm in control, 3.8 ${\pm}$ 1.6mm in experimental group 1, 4.1 ${\pm}$ 1.1mm in experimental group 2. The result clinically and statistically improved compared to baseline(P<0.01), but the difference found among the groups were not statistically significant. Postsurgery clinical attachment level was 1.6 ${\pm}$ 1.2mm in control, 3.5 ${\pm}$ 2.0mm in experimental group 1, 3.3 ${\pm}$ 1.2mm in experimental group 2. All of the control and experimental groups resulted in a statistically significant reduction from baseline(P<0.01). The reduction of the experimental groups were statistically significant from control(P<0.05). But the change between experimental group 1 and experimental group 2 was not statistically significant. We conclude that mixture of CC and FFSS is effective to periodontal regeneration in intrabony defect.