• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.4
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• pp.373-382
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• 2000

Temporomandibular disorders arised from joint itself was caused by inflammation or mechanical irritation of the retrodiskal tissues. Histologic changes of the retrodiskal tissues of temporomandibular joint(TMJ) internal derangement, such as inflammatory cell infiltration, hyalinization, myxoid change, fatty change, arterial obliteration, and so on, were reported, but relationships between magnetic resonance imaging(MRI) findings and histologic findings of the retrodiskal tissue were few reported. The purpose of this study was to find histologic changes of the retrodiskal tissues for status of joint and joint effusion in MRI of the temporomandibular joint which had surgical treatment. Materials were surgically treated 52 temporomandibular joints with internal derangement or osteoarthritis in TMJ clinic, Yongdong Severance Hospital. All joints were confirmed by magnetic resonance T1- and T2-weighted imagings bofere surgery. Status of joint was categorized by normal position, disc displacement with reduction, disc displacement without reduction, disc displacement without reduction associated with osteoarthrosis using preoperative MR T1-weighted images. Magnetic resonance evidence of joint effusion was observed in T2-weighted images and classified by its amount; degree 0(not observed), degree 1(small amount), degree 2(moderate amount), degree 3(large amount). Histologic features were observed whether the retrodiskal tissue has inflammatory cell infiltration, myxoid change, hyalinization, chondroid metaplasia and arterial obliteration. The distribution of elastic fibers were also observed. The results were as follows; 1. Inflammatory cell infiltration was not observed in any retrodiskal tissues. 2. MRI findings such as status of joint and evidence of joint effusion did not have significant relationship with myxoid change, hyalinization, chondroid metaplasia, arterial obliteration of the retrodiskal tissues. 3. Hyalinization and chondroid metaplasia were found in 8 joints(15.4%) and 5 joints(9.6%). All of them were found in disc displacement without reduction and disc displacement without reduction associated with osteoarthrosis. 4. Arterial obliteration was observed more frequently in disc displacement without reduction(55.6%) than disc displacement without reduction associated with osteoarthrosis(28.6%). Further studies with proper controls and more materials will be necessary.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.205-206
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• 2007

• The Journal of the Korean dental association
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• v.11 no.7
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• pp.467-468
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• 1973

A 25 years old female, feeling the pain to open the mouth, hard fooding mstication and expantion to left buccal area. Patient treated intra-oral fixation with rubber band and removed of uncomportable prosthetic works.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.543-544
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• 2011

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1221-1222
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• 2011

• Journal of Chest Surgery
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• v.49 no.3
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• pp.221-223
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• 2016

A 22-year-old man was hospitalized with a sternoclavicular joint (SCJ) dislocation caused by a traffic accident. Surgical reduction and fixation of the SCJ were performed using a T-plate. SCJ dislocation is rare, accounting for less than 1% of all dislocations, and is usually treated conservatively, although severe cases may require surgery. Surgery typically involves joint reduction and fixation using an autologous tendon graft, but this has disadvantages such as the requirement for additional surgery to obtain autologous tissue and an extended operative time. To overcome these issues, here, we performed a simple SCJ reduction and fixation using a T-plate and achieved good results.

• Korean Journal of Applied Biomechanics
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• v.24 no.2
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• pp.173-180
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• 2014

The purpose of this study was to investigate the effect of combined exercise on injury risk factors of lower extremity during landing. Ten sports talented athletes participated in this study. Sports talented athletes participated in a combined exercise (sports talented exercise, coordination) for 16 weeks. A three-dimensional motion analysis was performed using eight infrared cameras (sampling rate of 100 Hz), one force plate, and electromyography system (sampling rate of 1000 Hz) during landing. Kinetic, and kinematics analysis including average impulsive force, angle of lower extremity, vertical stiffness, onset of muscle activation were calculated by Matlab2009a software. Paired t-test was performed at alpha=.05. The average impulsive force in landing phase was not statistically significant (t=-.748, p=.474). The hip joint angle was more decreased in post test compared to pre test (E1: t=2.682, p=.025, E2: t=5.609, p=.000, E3: t=2.538, p=.032). The knee joint (E1: t=-.343, p=.739, E2: t=1.319, p=.220, E3: t=.589, p=.570) and ankle joint (E1: t=.081, p=.937, E2: t=.784, p=.453, E3: t=.392, p=.704) angle were tended to decrease after combined exercise. The vertical stiffness was tended to decrease after combined exercise (t=1.972, p=.080). Onset of quadriceps femoris (t=.698, p=.503) and medial gastocnemius (t=1.858, p=.096) were tended to be faster than biceps femoris (t=-.333, p=.747) after combined exercise. Although thses findings were not statistically significant except on a hip joint angle, risk factors of lower extremity such as joint angle, vertical stiffness and onset of quadriceps femoris, medial gastrocnemius were positively changed after the combined exercise but an additional training for improved onset of biceps femoris would be required in the future.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.11a
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• pp.51-54
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• 2005

The concrete structure hasn't perfect waterproofing performance but if it doesn't have a joint part that could isolate a permeability. Concrete structure(communication tunnel and underground structure) has an expansion joint and construction joint. There are a lot of joint type after construction or expansion, shrinkage, vibration, over load, performance of decline etc.. they offer a water of way by variety change. In this reason, It carries in effect a waterproofing work for the concrete structure of waterproofing. but the structure has a behavior that cause a problem by waterproofing layer of damage, heaving phenomenon, temperature of shrinkage. In this study, we will estimate a field of application for Sealer of injection type for leakage maintenance of construction standard on the waterproofing performance.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.6
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• pp.113-119
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• 2001

Experiments on the yield strength of pipe connectors made of metal wire, joint pins, pole pipes, multi span insertion joints, and T-clamp joints used in pipe houses were conducted. The strength of connections of a pipe connector made of metal wire was adequate but it had a big difference according to loading direction. Therefore as it is installed, its direction should be taken into consideration. The collapse load of pipes connected with a joint pin was lower than that of single pipes. In the part of frame member at which the great bending moment occurs, the use of joint pin should be avoided. Also experimental results showed that pole pipes for use in a part of frame buried under the ground were safe, and the strength of multi span insertion joints should be increased. The resistant moment of T-clamp was about 13.7% of a single pipe. In case that the external forces acting on left and right rafter are different. a unsymmetrical rotational force is produced at the multi span joint. If it is expected that the actual bending moment on the multi span joint is larger than resistant moment of T-clamp, a reinforcement to safely resist the rotational force is required.

• Structural Engineering and Mechanics
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• v.77 no.1
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• pp.89-102
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• 2021

Rapid construction of prefabricated bridges requires minimizing the field work of precast members and ensuring structural stability and constructability. In this study, we conducted experimental and analytical investigations of transverse joints of prefabricated T-girder bridge superstructures to verify the flexural performance and serviceability. In addition, we conducted parametric studies to identify the joint parameters. The results showed that both the segmented and continuous specimens satisfied the ultimate flexural strength criterion, and the segmented specimen exhibited unified behavior, with the flexural strength corresponding to that of the continuous specimen. The segmented specimens exhibited elastic behavior under service load conditions, and the maximum crack width satisfied the acceptance criteria. The reliability of the finite element model of the joint was verified, and parametric analysis of the convexity of the joint section and the compressive strength of the filler concrete showed that the minimum deflection and crack width occurred at a specific angle. As the strength of the filler concrete increased, the deflection and crack width decreased. However, we confirmed that the reduction in the crack width was hardly observed above a specific strength. Therefore, a design suitable for prefabricated bridges and accelerated construction can be achieved by improving the joint specifications based on the required criteria.