• Journal of Oral Medicine and Pain
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• v.21 no.2
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• pp.293-304
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• 1996

The purpose of this study was to investigate the peak electromyographic activity(EMG) and time intervals in firing sequence of Anterior temporalis(TA) and Masseter(MM) on clenching, the number of tender points in the head and neck muscles, the occlusal contact state on clenching, and their relationship. 78 patients with Temporomandibular Disorders(TMDs) participated and were classified into articular or muscular group by clinical signs and symptoms. BioEMG$\textregistered$ of integrated masticatory function analyzer, Biopak$\textregistered$ system(Bioresearch Inc., USA), was used to measure EMG and related items, and T- Scan$\textregistered$(Tekscan, USA), computerized occlusal analyser, was used to record occlusal contact state on maximum voluntary clenching. EMG and occlusal contact were synchronously recorded and analysed with SAS Statistical program. The results of this study were as follows : 1. In total subjects, EMG of TA was lower than that of MM in articular group but in muscular group, vice versa, As a result, the ratio TA to MM was significantly different between the two groups. no significant differece. 3. The number and force of occlusal contact were more in articular group, but there was no significant difference in Total Left-Right statistics(TLR) between the two groups. 4. In unilaterally affected subjects for muscle function, no significant difference was observed between the affected side and the contralateral side in articular group, but in muscular group, the item of the number of tender points showed significant difference. However, for occlusal contact items, contact force in articular group shows significant difference between the two sides. 5. Rate of coincidence of the first firing side of TA with affected side or preferred chewing side was higher and not different between the two groups, but no significant correlation was showed between the first firing side and the first occlusal contact side.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.2
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• pp.191-196
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• 2000

Purpose This study is to report presurgical magnetic resonance imaging(MRI) findings of the temporomandibular joint which had perforation in the disc or its surrounding tissues and to improve its diagnostic rate using MRI. Patients and Methods The sample consisted of patients who visited the TMJ clinic at Yongdong Severance Hospital, Yonsei University, during the years, 1992 and 1997. They were diagnosed as TMJ internal derangement and received surgical treatment. We divided them into two groups. The first group comprised of 85 joints with perforated disc or its surrounding tissues and which were confirmed surgically. The second group of 62 joints which only had disc displacement without perforation, hyperemia or adhesion served as control. Results The preoperative diagnostic sensitivity of TMJ perforation using MRI was 74.1%. The MRI findings for diagnosis of the TMJ perforation were degenerative change of the condyle head or the articular fossa, bone to bone contact between the condyle head and the articular eminence or the articular fossa, bony spurring or osteophytosis of the condyle head, flattening of articular surface of the condyle head or the articular eminence, discontinuity of the disc and the arthrographic effect due to joint effusion. Conclusion The preoperative diagnostic sensitivity of TMJ perforation using MRI in this study was 74.1% which was lower than the diagnostic rate using the arthrogram. Further investigations are needed to improve the diagnostic accuracy of TMJ perforation using MRI.

• The Journal of Korean Medicine
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• v.28 no.4
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• pp.148-157
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• 2007

Background & Objective: Articular cartilage is a potential target for drugs designed to inhibit the activity of matrix metalloproteinases (MMPs) to stop or slow the destruction of the proteoglycanand collagen in the cartilage extracellular matrix. The purpose of this study was to investigate the effects of Cinnamomum cassia in inhibiting the release of glycosaminoglycan (GAG), the degradation of collagen, and MMP activity in rabbit and human articular cartilage explants. Methods: The cartilage-protective effects of Cinnamomum cassia were evaluated by using glycosaminoglycan degradation assay, collagen degradation assay, colorimetric analysis of MMP activity, measurement of lactate dehydrogenase activity and histological analysis in rabbit cartilage explants culture. Results: Interleukin-1a (IL-1a) rapidly induced GAG, but collagen was much less readily released from cartilage explants. Cinnamomum cassia significantly inhibited GAG and collagen release in a concentration-dependent manner. Cinnamomum cassia dose-dependently inhibited MMP-1, MMP-3 and MMP-13 activities from IL-1a-treated cartilage explants culture when tested at concentrations ranging from 0.02 to 1 mg/ml. Conclusion : These results indicate that Cinnamomum cassia inhibits the degradation of proteoglycan and collagen through the down regulation of MMP-1, MMP-3 and MMP-13 activities of IL-1a-stimulated rabbit and human articular cartilage explants.

• Journal of Korean Foot and Ankle Society
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• v.13 no.1
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• pp.75-79
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• 2009

Purpose: To evaluate the outcomes of intra-articular calcaneal fractures treated using AO calcaneal plate surgically. Materails and Methods: Total 15 cases of intra-articular calcaneal fracture that treated with open reduction and internal fixation using AO calcaneal plate were evaluated. The patients were followed over a mean period of 19.8 months. The mean age was 41.6 years. By Sanders classification, there were 2 cases of type II, 10 cases of type III, and 3 cases of type IV. We evaluated radiological outcomes by Bohler angle, Gissane angle, calcaneal hight, calcaneal width and clinical outcomes by Creighton-Nebraska health foundation score. Results: All fractures united at a mean duration of 13.3 weeks. Radiologically, the mean preoperative Bohler angle was $8.5^{\circ}$ and restored to $23.3^{\circ}$. The mean preoperative Gissane angle was $118.7^{\circ}$ and restored to $124.2^{\circ}$. The mean preoperative calcaneal hight was 30.8 mm and restored to 38.9 mm. The mean preoperative calcaneal width was 41.3 mm and restored to 35.3 mm. 10 cases had excellent and good clinical outcomes and 5 cases having fair outcome. Conculsion: In our study, open reduction and internal fixation using AO calcaneal plate showed good results with anatomical restoration of articular surface and stable fixation without late collapse.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.1
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• pp.129-136
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• 2016

This study was performed to investigate whether an intra-articular injection of transient receptor potential vanilloid 1 (TRPV1) receptor agonist, resiniferatoxin (RTX) would alleviate behavioral signs of arthritic pain in a rat model of osteoarthritis (OA). We also sought to determine the effect of RTX treatment on calcitonin gene-related peptide (CGRP) expression in the spinal cord. Knee joint inflammation was induced by intra-articular injection of monosodium iodoacetate (MIA, $8mg/50{\mu}l$) and weight bearing percentage on right and left hindpaws during walking, paw withdrawal threshold to mechanical stimulation, and paw withdrawal latency to heat were measured to evaluate pain behavior. Intra-articular administration of RTX (0.03, 0.003 and 0.0003%) at 2 weeks after the induction of knee joint inflammation significantly improved reduction of weight bearing on the ipsilateral hindlimb and increased paw withdrawal sensitivity to mechanical and heat stimuli. The reduction of pain behavior persisted for 3~10 days according to each behavioral test. The MIA-induced increase in CGRP immunoreactivity in the spinal cord was decreased by RTX treatment in a dose-dependent manner. The present study demonstrated that a single intra-articular administration of RTX reduced pain behaviors for a relatively long time in an experimental model of OA and could normalize OA-associated changes in peptide expression in the spinal cord.

• Imaging Science in Dentistry
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• v.38 no.3
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• pp.153-161
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• 2008

Purpose : To compare and evaluate the diagnostic ability of cone beam computed tomography (CBCT) and magnetic resonance imaging (MRI) of the temporomandibular joint (TMJ). Materials and Methods : CBCT and MRI of 46 TMJs of 23 patients with TMJ disorders were evaluated. They were divided into 3 groups according to the position of the articular disc of the TMJ at closed mouth position and the reduction of the disc during open mouth position on MRI: no disc displacement group (NDD), disc displacement with reduction group (DDR), and disc displacement without reduction group (DDWR). With PACS viewing soft-wares, position of mandibular condyle in the articular fossa, osseous change of mandibular condyle, shape of articular fossa, and mediolateral and anteroposterior dimensions of mandibular condyle were evaluated on CBCT and MRI. Each value was tested statistically. Results : The position of mandibular condyle in the articular fossa were concentric in the NDD, DDR, and DDWR of CBCT and NDD of MRI. However, condyle was positioned posteriorly in DDR and DDWR of MRI. Flattening, sclerosis and osteophyte of the mandibular condyle were much more apparent on DDR of CBCT than MRI. And the erosion of the condyle was much more apparent on DDWR of MRI than CBCT. Box and Sigmoid types of articular fossa were found most frequently in DDR of MRI. Flattened type was found most frequently in DDR of CBCT and deformed type was found most frequently in DDWR of CBCT. No significant difference in mediolateral and anteroposterior dimensions were shown on CBCT and MRI. Conclusion : Since MRI and CBCT has unique diagnostic imaging ability, both modalities should be used together to supplement each other to evaluate TMJ.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.1
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• pp.71-92
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• 1999

This study is to analyze the stress and displacement on the jaws during the bilateral and unilateral clenching task on three dimensional finite element model of the dentated skull. For this study, the computed tomography(G.E.8800 Quick, USA) was used to scan the total length of human skull in the frontal plane at 1.9mm intervals. The CAD data were extracted from the tomograms through digitizer(Summa Sketch III, USA) and then reconstructed by means of the spline method in the CAD program. In this project, a commercial software I-DEAS(Master Series ver-sion 3.0, SDRC Inc, USA) was used for three-dimensional stress analysis on the finite element model. which consists of articular disc, maxilla, mandible, teeth, periodontal ligament and cranium. The results are as follows. ; 1. During the bilateral clenching, each major muscle forces caused high stresses on various areas of skull: masseter muscle on articular disc and teeth ; temporal muscle on mandible and periodontal ligament ; medial pterygoid muscle on the temporomandibular joint. During the unilateral clenching, masseter muscle induced the maximum stress ; medial pterygoid muscle the minimum stress. 2. During the bilateral clenching, higher compressive stresses on articular disc were generated by the masseter muscle and higher deformation occurred on the most front outer sites. And during the unilateral clenching, temporal muscle and medial pterygoid muscle exerted their forces to twist temporomandibular joint area of the balancing side and induced a higher compressive stresses on the front outer sites of articular disc. 3. During the bilateral clenching, the masseter muscle bended the mandible outwardly, and then caused tensile stresses on the lingual surface of mandibular symphysis. And the medial pterygoid muscle caused tensile stresses on the labial surface of mandibular symphysis. 4. When each muscles were simultaneously applied on jaws, a high stress and displacement took place on mandible rather than on the maxilla. Also, a high stress and displacement took place during the unilateral clenching rather than during the bilateral clenching.

• Clinics in Shoulder and Elbow
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• v.23 no.2
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• pp.94-99
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• 2020

Background: Intra-articular distal humeral fractures can be surgically challenging. It remains under discussion whether open reduction and internal fixation (ORIF) or total elbow arthroplasty (TEA) is more beneficial for treatment of the elderly. This study aimed to compare the clinical and functional outcomes of ORIF and TEA for managing intra-articular distal humerus fractures in patients aged 65 years or older. Methods: Patients who underwent ORIF (n=28) or TEA (n=43) for in intra-articular distal humerus fracture between May 2008 and December 2018 were reviewed. Range of motion, Mayo Elbow Performance Score (MEPS), Disabilities of the Arm, Shoulder, and Hand (DASH) score, radiologic outcomes, and surgical complications were evaluated at the final follow-up visit. Results: The ORIF and TEA groups showed a mean arc of flexion-extension of 97°±21° and 101°±12°, respectively. The mean MEPS and DASH scores were 94±15 and 27±12 points, respectively, in the ORIF group and 81±27 and 47±28 points in the TEA group. This difference was statistically significant. The incidence of total complications was similar between the groups. Conclusions: In patients older than 65 years with intra-articular distal humerus fracture, ORIF had better outcomes than TEA.

• Journal of the Optical Society of Korea
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• v.12 no.2
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• pp.98-102
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• 2008

Optical Coherence Tomography (OCT) is an important noninvasive medical imaging technique that can reveal subsurface structures of biological tissue. OCT has demonstrated a good correlation with histology in sufficient resolution to identify morphological changes in articular cartilage to differentiate normal through progressive stages of degenerative joint disease. Current OCT systems provide individual cross-sectional images that are representative of the tissue directly under the scanning beam, but they may not fully demonstrate the degree of degeneration occurring within a region of a joint surface. For a full understanding of the nature and degree of cartilage degeneration within a joint, multiple OCT images must be obtained and an overall assessment of the joint surmised from multiple individual images. This study presents frequency domain three-dimensional (3-D) OCT imaging of degenerative joint cartilage extracted from bovine knees. The 3-D OCT imaging of articular cartilage enables the assembly of 126 individual, adjacent, rapid scanned OCT images into a full 3-D image representation of the tissue scanned, or these may be viewed in a progression of successive individual two-dimensional (2-D) OCT images arranged in 3-D orientation. A fiber-based frequency domain OCT system that provides cross-sectional images was used to acquire 126 successive adjacent images for a sample volume of $6{\times}3.2{\times}2.5\;mm^3$. The axial resolution was $8\;{\mu}m$ in air. The 3-D OCT was able to demonstrate surface topography and subsurface disruption of articular cartilage consistent with the gross image as well as with histological cross-sections of the specimen. The 3-D OCT volumetric imaging of articular cartilage provides an enhanced appreciation and better understanding of regional degenerative joint disease than may be realized by individual 2-D OCT sectional images.

• Journal of Life Science
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• v.21 no.4
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• pp.534-541
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• 2011

Retinoic acid (RA), a metabolite of vitamin A, is known to regulate dedifferentiation of rabbit articular chondrocytes. The regulatory mechanism of dedifferentiation by RA is not yet understood. Thus, the effect of RA on the regulation of nitric oxide (NO)-induced dedifferentiation was investigated in rabbit articular chondrocytes. RA caused loss of the differentiated chondrocyte phenotype as demonstrated by inhibition of type II collagen expression and proteoglycan synthesis. RA also accelerated NO-induced dedifferentiation in rabbit articular chondrocytes as detected by expression of type II collagen and Sox-9 using Western blot analysis and production of sulfated proteoglycan using Alcain blue staining. Further, RA potentiated NO-induced activation of ERK. Inhibition of ERK with PD98059 (PD) recovered the expression of type II collagen and Sox-9 and production of sulfate proteoglycan in NO-induced dedifferentiated chondrocytes by RA treatment. Our findings suggest that RA accelerates NO-induced dedifferentiation of rabbit articular chondrocytes via the ERK pathway.