• The Journal of the Acoustical Society of Korea
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• v.42 no.6
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• pp.559-564
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• 2023

It is known that change in the bone strength of cortical bone constituting the outer shell of long bones such as the tibia or radius due to aging and osteoporosis is a risk factor for fracture. In this study, the group velocity of time-reversed Lamb waves generated in tibial cortical bone in vivo was measured using a time reversal method, and the correlations of the group velocity with the cortical bone thickness (cTh) and cortical bone mineral density (cBMD) closely related to the bone strength were investigated. It was found that the group velocity of time-reversed Lamb waves measured in the right tibia of 7 subjects showed a very high correlation, r = 0.90 (p < 0.0001), with the cTh and a relatively low correlation, r = 0.69 (p < 0.0001), with the cBMD. A limitation of this in vivo study is that the group velocity of time-reversed Lamb waves was measured for a normal group consisting of only 7 healthy adults. In the future, if the clinical usefulness of the time-reversed Lamb wave is demonstrated by follow-up studies on normal and osteoporotic groups consisting of a large number of healthy adults and osteoporotic patients, respectively, it is expected to improve the reliability of quantitative ultrasound technology for osteoporosis diagnosis. In addition, it is necessary to expand the skeletal site for measuring the group velocity of time-reversed Lamb waves not only to the tibia but also to the femur or radius.

• Journal of Trauma and Injury
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• v.18 no.2
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• pp.175-178
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• 2005

Fat embolism syndrome is a collection of respiratory, neurological and cutaneous symptoms and signs associated with trauma and other disparate surgical and medical conditions. The incidence of clinical syndrome is low while the embolization of marrow fat appears to be an almost inevitable consequence of long bone fractures. The pathogenesis is a subject of conjecture and controversy. There are two theories which have gained acceptance(mechanical theory, biochemical theory). Onset of symptom is usually within 12 to 72 hours, but may manifest as early as 6 hours to as late as 10 days. The classic triad of fat embolism syndrome involves pulmonary changes, cerebral dysfunction and petechial rash. The cornerstone of treatment is preventing the stress response, hypovolemia and hypoxia and operative stabilization of fractures. Corticosteroid are the only drugs which have repeatedly shown a positive effect on the prevention and treatment of fat embolism syndrome. We report a case of post-traumatic fat embolism syndrome with severe cerebral involvement without respiratory distress. A 55 years old female had a traffic accident. She sustained pelvic bone fracture and both humerus fracture. Approximately 4 hours after the accident, mental status change developed without a focal neurologic deficits. She had no respiratory symptom and sign. Her brain MRI showed multiple cerebral fat embolism lesion. The patients received supportive treatment with corticosteroid, albumin. Her neurologic status stabilized over several days. After orthopedic surgery, she was discharged 62 days after admission.

• Archives of Reconstructive Microsurgery
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• v.1 no.1
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• pp.31-38
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• 1992

The management of giant cell tumor involving juxta-articular portion has always been a difficult problem. In certain some giant cell tumors with bony destruction, a wide segmental resection may be needed for preventing to recur. But a main problem is preserving of bony continuity in bony defect as well as preservation of joint function. The traditional bone grafts have high incidence in recurrence rate, delayed union, bony resorption, stress fracture despite long immobilization and stiffness of adjuscent joint. We have attemped to overcome these problems by using a microvascular technique to transfer the fibula with peroneal vascular pedicle as a living bone graft. From Apr. 1984 to Nov. 1990, we performed the reconstruction of wide bone defect after segmental resection of giant cell tumor in 4 cases, using Vascularized Fibular Graft, which occur at the distal radius in 3 cases and at the proximal tibia in 1 case. An average follow-up was 2 years 8 months, average bone defect after wide segmental resection of lesion was 11.4cm. These all cases revealed good bony union in average 6.5months, and we got the wide range of motion of adjacent joint without recurrence and serious complications.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.2
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• pp.153-162
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• 2013

This study compared the marginal bone loss around dental implants that were placed in the canine areas of the mandibles and finded the survival rate of the implants, marginal bone loss around implants and prosthetic complications in 20 patients treated with overdentures retained with Locator attachments. Implants placed in this study showed a 95% survival rate and the average marginal bone loss was 1.21 mm($SD{\pm}0.60mm$) in 94.3 weeks of functional loading. Implant-retained overdentures had various prosthetic complications such as male change, metal cap loosening, Locator attachment loosening, denture teeth change, relining and denture fracture. Implant-retained overdentures using two implants and Locator attachments in the edentulous mandibles is considered as a stable way for long terms because of minimal invasive operation, simple prosthetic process and easy repair.

• Journal of Korean Neurosurgical Society
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• v.29 no.6
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• pp.763-771
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• 2000

Objectives : Thoracolumbar burst fractures(TBLF) result in not only compressive deformity of vertebral body but also spinal cord compression by bony fragments. Many thoracolumbar burst fractures demand both anterior decompression and intervertebral fusion. Most of spinal surgeons use anterior instrumentation for anteior intervertebral bony fusion. The use of Z-plate has been increased recently, however there has been only a few reports regarding its clinical long-term strength. We studied nineteen patients with TBLF to find out the long-term stability of Z-plate. Methods : We have operated 19 patients from March 1996 to August 1998. They were treated with anterior decompression through either a transthoracic, retroperitoneal extrapleural or retroperitoneal approach. Retropulsed bony fragments were removed completely by corpectomy. Iliac bone graft was used for interbody fusion in all of the cases. They were evaluated by plain X-ray films including flexion and extention lateral films. Cobbs angle was used to evaluate kyphotic and lateral wedging deformity. Results : Burst fractured sites were T11 in two, three T12, nine L1, and five L2. Mean follow-up duration was fifteen months. Preoperative average kyphotic angle was 23.7 degree. Immediate postoperative kyphotic angle was 10.2 degree. Follow-up resluts of average kyphotic angles revealed 14 degrees. Four patients(21%), including two spinal 3-column injury, showed increasement of kyphotic angle more than 5 degree or breakage of intrumentation. Two patients showed the difference of kyphotic angle more than 3 degree. Five patients(26%) revealed lateral wedging deformity more than 3 degrees. Postoperative complications were two meralgia parestheticas, one pulmonary atelectasis and two donor site infections. Four of the eight patients, who initially showed incomplete spinal cord deficits, were nerologically improved by Frankel's grade. Conclusion : Z-plate fixation and iliac bone graft after anterior decompression in thoracolumbar burst fractures is a safe and easy method. Immediate postoperative results revealed excellent correction of posttraumatic kyphosis, but long-term follow-up evalution showed insufficient strength. Therefore we believe that use of Z-plate should be carefully decided, especially in the case of large lumbar fracture or 3-column injury.

• Journal of Life Science
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• v.28 no.7
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• pp.874-883
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• 2018

Osteoporosis is a disease that increases the risk of fracture by decreasing the mass and strength of bone. It is caused by imbalance of osteoclast bone formation and osteoclast bone resorption. Bone formation by osteoblast is activated via bone morphogenetic proteins and runt-related transcription factor 2. $Wnt/{\beta}-catenin$ signaling and bone resorption by osteoclast are initiated by the binding of receptor activator of nuclear $factor-{\kappa}B$ ligand and receptor activator of nuclear $factor-{\kappa}B$. Menopausal women are at risk for many diseases due to hormonal imbalances, and osteoporosis is the most common metabolic disorder in 30% of postmenopausal women. When estrogen is deficient, bone resorption of osteoclasts is promoted, and the risk of osteoporosis especially increases in postmenopausal women. Hormone replacement therapy has been widely used to relieve or treat the symptoms of menopausal syndrome. However, long-term administration of hormone therapy has been associated with a high risk of side effects, such as breast cancer, ovarian cancer, and uterine cancer. Recently, phytochemicals have been actively studied as a phytoestrogen, which has an estrogen-like activity to cope with symptoms of menopausal syndrome. Therefore, in this review, we investigated the differentiation mechanism of osteoblast and osteoclast and the role of estrogen and phytoestrogen in bone metabolism in relation to previous studies.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.4
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• pp.394-404
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• 2006

Statement of problem: A conventional 3-unit fixed partial denture design with a pontic between two retainers is the most commonly used. However in cases where the mental nerve is in close proximity to the second premolar, a cantilever design can be considered. As such, logical and scientific evidence is lacking for the number and position of implants to be placed for partially edentulous patients, and no clear-cut set of treatment principles currently exist. Purpose : The purpose of this study was to evaluate prognosis of implant-supported fixed partial dentures and to compare changes in bone level which may rise due to the different factors. Material and method : The present study examined radiographical marginal bone loss in patients treated with implant-supported fixed partial dentures (87 prostheses supported by 227 implants) and evaluated the influence of the span of the pontic, type of the opposing dentition. Clinical complications were studied using a retrospective method. Within the limitation of this study. the following result were drawn Result, 1. Seven of a total of 227 implants restored with fixed prostheses failed, resulting in a 96.9% success rate. 2. Complications encountered during recall appointments included dissolution of temporary luting agent (17 cases), porcelain fracture (8 cases), loosened screws (5 cases), gingival recession (4 cases), and gingival enlargement (1 case). 3. Marginal bone loss, 1 year after prosthesis placement, was significant(P<0.05) in the group that underwent bone grafting, however no difference in annual resorption rate was observed afterwards. 4. Marginal bono loss, 1 year post-placement, was greater in cantilever-type prostheses than in centric pontic protheses (P<0.05). 5. Marginal bone loss was more pronounced in posterior regions compared to anterior regions (P<0.05). 6. The degree of marginal bone loss was proportional to the length of the pontic (P<0.05). Conclusion: The success rate of implant-supported fixed partial dentures, including marginal bone loss, was satisfactory in the present study. Factors influencing marginal bone loss included whether bone graft was performed, location of the pontic (s), location of the surgical area in the arch pontic span. Long-term evaluation is necessary for implant-supported fixed partial dentures, as are further studies on the relationship between functional load and the number of implants to be placed.

• Clinics in Shoulder and Elbow
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• v.2 no.1
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• pp.14-20
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• 1999

Purpose: Despite of the popular use of the reconstruction plate for the fixation of clavicular shaft fractures, some disadventages have been raised such as long period of immobilization, long skin incision, loosening of plate and screws, and increased chance of nonunion due to severe periosteal injury. Thus, the authors have performed intramedullary multiple Steinmann pins fixation that could reduce the disadvantages of plate fixation in order to compare the treatment results between the two groups. Materials & Methods: From 1994. Jan. to 1997. Dec. the department of orthopaedic surgery of the Kwak's hospital treated operatively for 56 cases of the clavicular shaft fractures in adult. 39 cases of them were treated with the plate fixation and 17 cases with the intramedullary multiple Steinmann pins fixation(SP group). Reconstruction plates(Plate group) were used for 26 out of 39 patients treated with plate fixation. Among the Plate group and SP group, each 15 cases were selected by age and sex and compared each other according to the bone union time, union rate, complication, and functional results. The follow-up period was 12 months at the shortest and 48 months at the longest and the average was 16 months. Results: The Plate group showed that the bone union time was 7 weeks and the bone union rate was 93%. The SP group showed 6.5 weeks and 100% respectively. In complication, the Plate group had 1 case of loosening of plate and screws and delayed union; SP group had 1 case of pin migration. The functional results according to Kang's criteria, 87% of the Plate group and 93% of the SP group showed good or excellent. Conclusion : The SP group showed very comparable results in terms of the bone union time, bone union rate, complication, and functional results comparing to the Plate group. The intramedullary multiple Steinmann pins fixation showed several advantages over the reconstruction plate fixation, which were simple operative technique, easy removal of pins, being able to perform immediate postoperative full range of motion exercise. Therefore, the intramedullary multiple Steinmann pins fixation is thought to be one of the useful operative techniques in treatment of the clavicular shaft fractures in adult.

• The Korean Journal of Pain
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• v.9 no.2
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• pp.426-429
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• 1996

Complex regional pain syndrome Type II(CRPS) can be diagnosed by new IASP criteria in 1994. Sympathetically maintained pain may or may not be present in a patient with complex regional pain syndrome. We experienced a CRPS Type II patient who has sympathetically maintained pain as a major painful nature developed after right multiple iliac bone fracture, right femoral artery thrombosis and lumbosacral plexus injury. Combination treatment with L2, L3, L4 sympathetic ganglion block and continuous lower thoracic epidural block for 30 days were tried to get long term effect. The patient had signs of successful. sympathetic denervation of the right foot. After that pain relief was sustained until three month later.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.277-278
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• 1998

CT/MRI images were frequently taken to evaluate the anatomic structure and disease status, and to plan the treatment modality for oral and maxillofacial surgery. However, surgeons have many difficulties in reading and understanding 2D images without long time experiences. This study presents the method of 3D reconstruction with fine CT slices and its clinical application. We applied this method a clinical patient with oral and maxillofacial trauma and produced 3D reconstructed model which shows the fracture line in panfacial area and bone defect.