• Maxillofacial Plastic and Reconstructive Surgery
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• v.15 no.2
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• pp.81-91
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• 1993

Arthrosis of the temporomandibular joint is defined as a disease of a joint with chief complaint of pain, clicking, limited jaw movements. Generally, most patients with the temporomandibular arthrosis can be treated conservatively with muscle relaxation therapy combined with mandibular repositioning prostheses, followed by occlusal equilibration, restorative dentistry and/or orthodontics, and many other forms of treatment. In case prior nonsurgical treatment proved to be ineffective or the disease is chronic and severe, surgical operation is recommended. For patients with arthrosis of the temporomandibular joint, only discectomy as therapeutic method of the surgical treatment should not be applied and the removed articular disc of the temporomandibular joint should be replaced. Allograft such as Proplast-Teflon, Silastic, etc have been used as replacements of removed articular disc. However, these allograft materials have caused complications such as inflammatory changes, foreign body reactions. As a result, a replacement material which is autogenous, space occupying, easy to harvest and less inflammatory change has been developed. Auricular cartilage with perichondrium satisfies many of these requirements. The apparent advantages of autogenous auricular cartilage as an interpositional graft after a discectomy are as follows, (1) the form of the external ear corresponds to joint morphology, (2) a graft of adequate size can be harvested, (3) the form of the external ear remains unchanged after surgery, (4) the graft can be obtained adjacent to the surgical site, (5) biologically acceptable material is used, (6) the additional expense of allogenic graft is avoided. Because we considered autogenous auricular cartilage as a good replacement material, removed articular disc has been replaced with fresh autogenous auricular cartilage in the case of three patients. The result of the treatment is favorable, and the cases being presented here.

• Korean Journal of Environment and Ecology
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• v.31 no.4
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• pp.420-427
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• 2017

The purpose of this study was to investigate the indirect effects of forest using the forest healing factors such as landscape and hearing factors on mood improvement. The experiment was conducted for about 2 months from October 5, 2016 to November 30, 2016 targeting 30 healthy college students ($23.6{\pm}1.7$ years old). After making 3 factors(image factor, sound factor and image+sound factor) using scenery and sound of both forest and urban space, participants undergone the test in a room. And the effects of these 3 factors on the mood improvement were compared and analyzed using SPSS 18.0 program. Profile of Mood State test (POMS) and Semantic Differential method (SD) were used to measure mood improvement as a psychological test. As a result, indirect forest stimulation showed effects of suppressing tension, fatigue, anger, confusion, depression, and enhancement of vitality. No significant difference was observed in the comparison between forest stimuli. However, Compared with the urban stimuli, the stimulation of the forests has the effect of enhancing pleasant, natural feeling and calmness.

• Korean Journal of Materials Research
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• v.20 no.6
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• pp.331-337
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• 2010

A highly porous Biphasic Calcium Phosphate (BCP) scaffold was fabricated by the sponge replica method with a microwave sintering technique. The BCP scaffold had interconnected pores ranging from $80\;{\mu}m$ to $1000\;{\mu}m$, which were similar to natural cancellous bone. To enhance the mechanical properties of the porous scaffold, infiltration of polycaprolactone (PCL) was employed. The microstructure of the BCP scaffold was optimized using various volume percentages of polymethylmethacrylate (PMMA) for the infiltration process. PCL successfully infiltrated into the hollow space of the strut formed after the removal of the polymer sponge throughout the degassing and high pressure steps. The microstructure and material properties of the BCP scaffold (i.e., pore size, morphology of infiltrated and coated PCL, compressive strength, and porosity) were evaluated. When a 30 vol% of PMMA was used, the PCL-BCP scaffold showed the highest compressive strength. The compressive strength values of the BCP and PCL-BCP scaffolds were approximately 1.3 and 2MPa, respectively. After the PCL infiltration process, the porosity of the PCL-BCP scaffold decreased slightly to 86%, whereas that of the BCP scaffold was 86%. The number of pores in the $10\;{\mu}m$ to $20\;{\mu}m$ rage, which represent the pore channel inside of the strut, significantly decreased. The in-vitro study confirmed that the PCL-infiltrated BCP scaffold showed comparable cell viability without any cytotoxic behavior.

• The Journal of the Korean bone and joint tumor society
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• v.1 no.1
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• pp.52-59
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• 1995

Metastatic cancer is the most common tumor of the skeleton. The prevalence of pathologic fracture may increase as patient survival is prolonged by improved cancer therapy. With recent advances in orthopaedic procedure and medical management of terminal cancer patients, it is generally agreed that aggressive treatment should be undertaken for patient with pathologic fracture secondary to metastatic disease, and a team approach should be utilized. The authors have reviewed twenty cases of pathologic fracture of the long bone due to metastatic tumor treated in the Department of Orthopedic Surgery, Yonsei University College of Medicine, from April 1989 to April 1994 and the following results were obtained. 1. The mean age at surgery was 58.4 years (ranged from 24years to 86years) and among 20 cases, 10 cases were male and the others were female. 2. The most frequent site of pathologic fracture in long bone is femur(15 cases, 75%), and followed by humerus(4 cases, 20%), tibia(1 case). 3. The frequently encountered primary tumors that metastases to long bone are those of the lung(7 cases, 35%), breast(4 cases, 20%), and prostate(2 cases, 10%). 4. The operative procedure was performed by resection of the tumor mass extensively, and we used polymethylmetacrylate for filling the dead space after resection, in all cases. 5. The mean survival period after operation is 9.2 months(ranged from 1 month to 4 years and 9 month). 6. The results of postoperative pain relief status were graded as fair to excellent in 17 cases(85%).

• Journal of Korean Neurosurgical Society
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• v.58 no.1
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• pp.1-8
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• 2015

Treatment of Leptomeningeal carcinomatosis (LMC) from solid cancers has not advanced noticeably since the introduction of intra-cerebrospinal fluid (CSF) chemotherapy in the 1970's. The marginal survival benefit and difficulty of intrathecal chemotherapy injection has hindered its wide spread use. Even after the introduction of intraventricular chemotherapy with Ommaya reservoir, frequent development of CSF flow disturbance, manifested as increased intracranial pressure (ICP), made injected drug to be distributed unevenly and thus, the therapy became ineffective. Systemic chemotherapy for LMC has been limited as effective CSF concentration can hardly be achieved except high dose methotrexate (MTX) intravenous administration. However, the introduction of small molecular weight target inhibitors for primary cancer treatment has changed the old concept of 'blood-brain barrier' as the ultimate barrier to systemically administered drugs. Conventional oral administration achieves an effective concentration at the nanomolar level. Furthermore, many studies report that a combined treatment of target inhibitor and intra-CSF chemotherapy significantly prolongs patient survival. Ventriculolumbar perfusion (VLP) chemotherapy has sought to increase drug delivery to the subarachnoid CSF space even in patients with disturbed CSF flow. Recently authors performed phase 1 and 2 clinical trial of VLP chemotherapy with MTX, and 3/4th of patients with increased ICP got controlled ICP and the survival was prolonged. Further trials are required with newly available drugs for CSF chemotherapy. Additionally, new LMC biologic/pharmacodynamic markers for early diagnosis and monitoring of the treatment response are to be identified with the help of advanced molecular biology techniques.

• Journal of Korean Neurosurgical Society
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• v.56 no.6
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• pp.527-530
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• 2014

Spinal subarachnoid hemorrhages (SAH) can extend into the intracranial subarachnoid space, but, severe cerebral vasospasm is rare complication of the extension of intracranial SAH from a spinal subarachnoid hematoma. A 67-year-old woman started anticoagulant therapy for unstable angina. The next day, she developed severe back pain and paraplegia. MRI showed intradural and extramedullar low signal intensity at the T2-3, consistent with intradural hematoma. High signal intensity was also noted in the spinal cord from C5 to T4. We removed subarachnoid hematoma compressing the spinal cord. The following day, the patient complained of severe headache. Brain CT revealed SAH around both parietal lobes. Three days later, her consciousness decreased and left hemiplegia also developed. Brain MRI demonstrated multiple cerebral infarctions, mainly in the right posterior cerebral artery territory, left parietal lobe and right watershed area. Conventional cerebral angiography confirmed diffuse severe vasospasm of the cerebral arteries. After intensive care for a month, the patient was transferred to the rehabilitation department. After 6 months, neurologic deterioration improved partially. We speculate that surgeons should anticipate possible delayed neurological complications due to cerebral vasospasm if intracranial SAH is detected after spinal subarachnoid hematoma.

• Archives of Plastic Surgery
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• v.32 no.2
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• pp.183-188
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• 2005

Defect on the temporal area caused by, surgical ablation of a tumor or an infection should be reconstructed immediately to prevent potentially life-threatening complications such as meningitis and cerebrospinal fluid leakage. The defect on the temporal area usually presents as a typical 'cone-shape'. Successful reconstruction requires sufficient volume of well-vascularized soft tissue to cover the exposed bone and dura. From 1994 through 2003, the authors applied rectus abdominis free flap for the reconstruction of the temporal defect from 1994 through 2003. There were 10 patients with a mean age of 52.1 years. Of these 10 patients, external auditory canal cancer was present in four patients, temporal bone cancer in two, parotid gland cancer in one and three patients were reconstructed after debridement of infection(destructive chronic otitis media). All the free flaps survived, and flap-related complications did not occur. Compared to a local flap, the rectus abdominis free flap can provide sufficient volume of well-vascularized tissue to cover the large defect and can be well-tolerated during an adjuvant radiation therapy. The long and flat muscle can be easily molded to fit in to the 'cone-shape' temporal defect without dead space. It is also preferred because of the low donor site morbidity, a large skin island and an excellent vascular pedicle. Two-team approach without position change is possible. In conclusion, the authors think that rectus abdominis free flap should be considered as one of the most useful method for the reconstruction of a cone-shaped temporal defect.

• Journal of Chest Surgery
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• v.50 no.3
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• pp.202-206
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• 2017

Background: Empyema is the collection of purulent exudate within the pleural space. Overall, 36%-65% of patients with empyema cannot be treated by medical therapy alone and require surgery. Multiloculated empyema is particularly difficult to treat with percutaneous drainage. Therefore, we describe our experiences with early aggressive surgical treatment for rapid progressive multiloculated empyema. Methods: From January 2001 to October 2015, we retrospectively reviewed 149 patients diagnosed with empyema who received surgery. The patients were divided into 2 groups according to whether they underwent emergency surgery or not. We then compared surgical outcomes between these groups. Results: The patients in group A (emergency surgery, n=102) showed a more severe infectious state, but a lower complication rate and shorter length of hospital stay. The incidence of lung abscess was higher in group A, and abscesses were associated with diabetes and severe alcoholism. Conclusion: Early aggressive surgical treatment resulted in good surgical outcomes for patients with rapid progressive multiloculated empyema. Furthermore, we suspect that the most likely causes of multiloculated empyema are lung abscesses found in patients with diabetes mellitus as well as severe alcoholism.

• Journal of Korean Neurosurgical Society
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• v.29 no.5
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• pp.701-705
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• 2000

Solitary plasmacytomas are rare and account for 5-10% of all plasma cell disorders. These tumors are categorized as solitary plasmacytomas of bone(osseous) or extramedullary plasmacytomas(non-osseous). About a half of solitary plasmacytomas of bone occur in the spine but rarely in the skull. We report a case of solitary plasmacytoma of the skull presented with a painless palpable left parietal calvarial mass in an otherwise asymptomatic 38- year-old man. Skull radiographs showed a large radiolucent lesion with well defined non-sclerotic margins. Computed tomograph scan demonstrated a markedly enhancing mass extending from the epidural to the subcutaneous space. The patient underwent surgery and tumor was completely excised. Pathological examination showed tumor to be a plasmacytoma synthesizing IgG. Postoperatively, the patient received radiotherapy. There was no evidence of systemic involvement on postoperative laboratory wokups. Our recommended treatment is a complete surgical excision combined with postoperative radiation therapy. The patient should be follwed carefully for more than 10 years because of either local recurrence or possible progression to multiple myeloma.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1983-1989
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• 2005

Industrial robots are powerful, extremely accurate multi-jointed systems, but they are heavy and highly rigid because of their mechanical structure and motorization. Therefore, sharing the robot working space with its environment is problematic. A novel pneumatic artificial muscle actuator (PAM actuator) has been regarded during the recent decades as an interesting alternative to hydraulic and electric actuators. Its main advantages are high strength and high power/weight ratio, low cost, compactness, ease of maintenance, cleanliness, readily available and cheap power source, inherent safety and mobility assistance to humans performing tasks. The PAM is undoubtedly the most promising artificial muscle for the actuation of new types of industrial robots such as Rubber Actuator and PAM manipulators. However, some limitations still exist, such as the air compressibility and the lack of damping ability of the actuator bring the dynamic delay of the pressure response and cause the oscillatory motion. In addition, the nonlinearities in the PAM manipulator still limit the controllability. Therefore, it is not easy to realize motion with high accuracy and high speed and with respect to various external inertia loads in order to realize a human-friendly therapy robot To overcome these problems a novel controller, which harmonizes a phase plane switching control method with conventional PID controller and the adaptabilities of neural network, is newly proposed. In order to realize satisfactory control performance a variable damper - Magneto-Rheological Brake (MRB) is equipped to the joint of the manipulator. Superb mixture of conventional PID controller and a phase plane switching control using neural network brings us a novel controller. This proposed controller is appropriate for a kind of plants with nonlinearity uncertainties and disturbances. The experiments were carried out in practical PAM manipulator and the effectiveness of the proposed control algorithm was demonstrated through experiments, which had proved that the stability of the manipulator can be improved greatly in a high gain control by using MRB with phase plane switching control using neural network and without regard for the changes of external inertia loads.