• Journal of the Korean Society for Precision Engineering
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• v.25 no.11
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• pp.119-125
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• 2008

The objective of this study was to compare micro-scale friction coefficients with and without synovial fluid, and micro-scale measurements were performed using atomic force microscopy (AFM) with a $5{\mu}m$ spherical probe. Four cylindrical cartilage specimens were harvested from two fresh bovine humeral heads (4-6 months old). $Average{\pm}standard$ deviation values of the micro-scale AFM frictional coefficients calculated from the liner fit of friction versus normal force was $0.177{\pm}0.012$ and $0.130{\pm}0.010$ with and without synovial fluid coating on AFM probe respectively, showing its reduction by ${\sim}27%$ with synovial fluid. To the best of our knowledge, this experimental study investigates the first such comparisons of frictional response of articular cartilage with and without synovial fluid coating on AFM probe, and provides significant insights into the role of synovial fluid in the articular cartilage friction and lubrication independently of the confounding effect of fluid pressurization in the articular cartilage.

• Imaging Science in Dentistry
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• v.36 no.2
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• pp.103-109
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• 2006

Purpose : To evaluate position of the mandibular condyle within articular fossa in an asymptomatic population radiographically by a cone beam computed tomography. Materials and Methods : Cone beam computed tomography of 60 temporomandibular joints was performed on 15 males and 15 females with no history of any temporomandibular disorders, or any other orthodontic or prosthodontic treatments. Position of mandibular condyle within articular fossa at centric occlusion was evaluated. A statistical evaluation was done using a SPSS. Results : In the sagittal views, mandibular condyle within articular fossa was posteriorly located at medial and central sections. In the coronal views, mandibular condyle within articular fossa was laterally located at central section. Mandibular condyles in the right and left sides were showed asymmetric positional relationship at medial, central, and lateral sections. Conclusion : Mandibular condyle within articular fossa in an asymptomatic population was observed nonconcentric position in the sagittal and coronal views.

• Imaging Science in Dentistry
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• v.37 no.1
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• pp.19-26
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• 2007

Purpose : To examine whether the maxillofacial skeletal morphology correlates with the condylar position and the anatomic characteristics of articular eminence using measurements of lateral cephalometric radiographs and individualized sagittal temporomandibular joint (TMJ) tomographs. Materials and Methods : I compared measurements of 202 TMJs of 101 orthodontic patients of Kangnung National University Dental Hospital. 1 used Pearson's correlation for comparison of the measuring values in lateral cephalometric radiographs and individualized sagittal TMJ tomographs. Results : Large occlusal plane angle tendency showed decreased width of posterior eminence slope, decreased depth of articular fossa and decreased posterior slope angle of eminence. Large mandibular plane angle tendency showed decreased superior joint space, decreased depth of articular fossa and decreased posterior slope angle of eminence. Large genial angle tendency showed decreased depth of articular fossa, decreased posterior slope angle of eminence and anterior position of condylar head. Large anterior facial height and large posterior facial height tendency showed increased width of posterior slope of eminence, increased depth of articular fossa, increased posterior slope angle of eminence and posterior position of condylar head. Conclusion : Maxillofacial skeletal morphology has correlation with the anatomic characteristics of TMJ. Individualized sagittal TMJ tomographs can provide useful information for anatomical analysis of TMJ.

• Journal of Oral Medicine and Pain
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• v.11 no.1
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• pp.37-43
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• 1986

The purpose of this study was to investigate the effects of the posterior slope of articular eminence on internal derangement of temporomandibular joint. The author had taken transcranial oblique lateral projections of both TMJs in 30 normal subjects and 40 internal derangement patients who had 54 affected sides and 26 unaffected sides, and then analyzed the films. The results were as follows : In normal subjects, there was no significant difference between in the males and females, and between in the right and left sides. The posterior slope of articular eminence of affected sides in patients was stiffer than that of unaffected sides in patients and also stiffer than that of normal subjects. Therefore, the author concluded that stiffer posterior slope of articular eminence was, the more susceptibility to internal derangement would be.

• Biomolecules & Therapeutics
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• v.7 no.4
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• pp.347-353
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• 1999

Osteoarthrosis was induced in rabbit knees through resecton of anterior cruciate ligament. Sodium hyaluronate (1%) was administerated into articular space at the dose levels of 0.1 mg/kg once a week using 1ml sylinge and 26G needle for test groups. Saline was administrated for control groups. After 6 and 12 weeks, animals were sacrificed to conduct macroscopic observation and histopathologic examination. The articular lesions were evaluated and test groups were compared with control groups. No significant differencies were showed between test groups and control groups at macroscopic observation in both 6- and 12- week groups. In histopathologic examination, control groups showed higher osteoarthrosis than test groups. The articular surfaces of control groups showed fibrillation, denudation, pannus formation and hypocellularity. The articular surfaces of test groups showed fibrillaton and hypercellularity. These indicate that sodium hyaluronate has inhibitory effects on osteoarthrosis at least in rabbit and could be used for treatment of osteoarthrosis.

• Journal of Korean Foot and Ankle Society
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• v.19 no.4
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• pp.137-141
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• 2015

Recently, open reduction and internal fixation has been the treatment of choice for displaced intra-articular calcaneal fractures for many orthopaedic surgeons. However controversy still surrounds the optimal treatment with regard to whether displaced intra-articular calcaneal fractures should be treated operatively or conservatively. Conservative treatments include use of splint, rest, leg elevation, icing, use of analgesics and early mobilization. Operative treatment is open reduction and internal fixation, performed through an extensile lateral approach with interfragmentary screws and application of a neutralization plate. We reviewed the question of whether operative treatment by open reduction and internal fixation provides a benefit compared with conservative treatment for displaced intra-articular calcaneal fractures.

• Journal of Oral Medicine and Pain
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• v.44 no.4
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• pp.189-194
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• 2019

Perforation of articular disc of temporomandibular joint is a unusual condition and diagnosed through magnetic resonance imaging (MRI), arthrography or arthroscopic surgery. We attempted to investigate the suspicious findings of articular disc perforation through examination commonly used in temporomandibular disorder (TMD) patients. We retrospectively analyzed the clinical and imaging findings of five TMD patients whose articular discs were perforated based on MRI. The most meaningful finding was the abnormal width of the joint space in cone-beam computed tomography. Thus, the clinician should perform a thorough assessment of the joint space in TMD patients and conduct additional investigation to determine what caused the abnormal joint space.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.7 s.184
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• pp.67-75
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• 2006

One of challenging topics for humanoid hands is to modulate a human-like motion of humanoid fingers handling an object. To this end, recognizing the motion behavior of human fingers is very important aspect. Based on this concept, this paper identifies the .joint trajectories of human fingers for an operation of hand opening and closing, and specifies an empirical model that coordinates an inter-articular relationship of human fingers doing the given motion. It is expected that the inter-articular model presented in this paper is applicable for humanoid fingers to mimic the natural motion of human fingers.

• The Korean Journal of Pain
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• v.24 no.2
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• pp.69-73
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• 2011

Although the incidence of partial-thickness rotator cuff tears (PTRCTs) was reported to be from 13% to 32% in cadaveric studies, the actual incidence is not yet known. The causes of PTRCTs can be explained by either extrinsic or intrinsic theories. Studies suggest that intrinsic degeneration within the rotator cuff is the principal factor in the pathogenesis of rotator cuff tears. Extrinsic causes include subacromial impingement, acute traumatic events, and repetitive microtrauma. However, acromially initiated rotator cuff pathology does not occur and extrinsic impingement does not cause pathology on the articular side of the tendon. An arthroscopic classification system has been developed based on the location and depth of the tear. These include the articular, bursal, and intratendinous areas. Both ultrasound and magnetic resonance image are reported with a high accuracy of 87%. Conservative treatment, such as subacromial or intra-articular injections and suprascapular nerve block with or without block of the articular branches of the circumflex nerve, should be considered prior to operative treatment for PTRCTs.

• The Journal of the Korean dental association
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• v.9 no.10
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• pp.611-615
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• 1971

The articular discs from temporomandibular joints of thirty men and women whose ages ranged between 20 and 70 years hve been used in this study. The articular discs of the temporomandibular joints of human postmortem material was examined individually by means of microscopic techniques. The following changes were seen: 1. With advancing age some of fibroblast was developed into chondroid cells. Which later may differentiate into true chondrocytes. 2. In young individuals the elastic fibers found only I relatively small numbers. With advancing age elastic fibers was increased in number. 3. With advancing age the arrangement of fibrous tissue are irregular and loosely separated. 4. In the discs, as well as in the fibrous tissue covering the articular surfaces, this cellular changes seems to be dependent upon mechanical influences.