• Journal of Oral Medicine and Pain
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• v.36 no.2
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• pp.107-115
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• 2011

We report 4 patients who developed change of occlusion which seemed to be related to anterior disc dislocation without reduction, but there was no distinct evidence of condylar destruction or collapse. They experienced sudden occurrence of occlusal change, anterior open bite in 2 patients, lateral CR-CO discrepancy in 1 patient, and anteroposterior CR-CO discrepancy in 1 patient. Also, this report is to find out if there is a relation between sudden occurrence of occlusal change and anterior disc dislocation without reduction.

• Journal of Oral Medicine and Pain
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• v.39 no.4
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• pp.152-155
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• 2014

Temporomandibular joint (TMJ) dislocation is defined that the disc-condyle complex is positioned anterior to the articular eminence in the open mouth position, and is unable to return to a normal closed mouth position without a manipulative maneuver. TMJ dislocation can recur habitually and result several problems to patients such as discomfort, pain, fear, and anxiety. The only definitive treatment for TMJ dislocation is surgical alteration of the joint itself. In most cases, however, a surgical procedure is far too aggressive for the symptoms experienced by the patient. In addition, the effect of surgical treatment may be insufficient, and the recurrence have been reported. It is also possible to develop several complications after surgical treatment. Therefore much effort should be directed at supportive therapy in an attempt to eliminate the disorder or at least reduce the symptom to tolerable levels. Through this cases the authors present favorable treatment outcome using occlusal splint with the patient of TMJ dislocation. Occlusal splint therapy can be considered as easy, safe, and useful non-invasive modality to treatment of TMJ dislocation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.36 no.1
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• pp.16-20
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• 2014

Mandibular condylar hyperplasia is an uncommon condition of excessive unilateral growth of the condyle causing facial asymmetry and occlusal alterations. The etiology of condylar hyperplasia is unclear, but several factors are suspected, including previous trauma, hormonal disturbances, and abnormal functional loadings. Acute or chronic recurrent dislocation of temporomandibular joint (TMJ) is common, but long-standing dislocation is rare. We present two cases of the exophytic condylar hyperplasia that lasted for over 20 years with TMJ dislocation. In both cases, we performed a condyloplasty to restore normal occlusion and facial symmetry, with satisfactory results.

• Journal of Trauma and Injury
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• v.25 no.1
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• pp.7-16
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• 2012

Purpose: Cervical dislocations with locked facets account for more than 50% of all cervical injuries. Thus, investigating a suitable management of cervical locked facets is important. This study examined factors of close reduction failure in traumatically locked facets of the subaxial cervical spine patients to determine suitable surgical management. Methods: We retrospectively analyzed of the case histories of 28 patients with unilateral/bilateral cervical locked facets from Nov. 2004 to Dec. 2010. Based on MRI evaluation of disc status at the injury level, we found unilateral dislocations in 9 cases, and bilateral dislocations in 19 cases, The patients were investigated for neurologic recovery, closed reduction rate, factors of the close reduction barrier, fusion rate and period, spinal alignment, and complications. Results: The closed reduction failed in 23(82%) patients. Disc herniation was an obstacle to closed reduction (p=0.015) and was more frequent in cases involving a unilateral dislocation (p=0.041). The pedicle or facet fracture was another factor, although some patients showed aggravation of neurologic symptoms, most patients had improved by the last follow up. The kyphotic angle were statistically significant (p=0.043). Sixs patient underwent anterior decompression/fusion, and 15 patients underwent circumferential fusion, and 7 patients underwent posterior fusion. All patients were fused at 3 months after surgery. The complications were 1 case of CSF leakage and 1 case of esphageal fistula, 1 case of infection. Conclusion: We recommend closed reduction be performed as soon as possible after injury to maximize the potential for neurological recovery. Patients fot whom closed reduction of the cervical locked facets have a higher incidence of anatomic obstacles to reduction, including facet fractures and disc herniation. Immediate direct open anterior reduction or circumferential fixation/fusion of locked cervical facets is recommended as a treatment of choice for traumatic locked cervical facet patients after closed reduction failure.

• Journal of Oral Medicine and Pain
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• v.37 no.4
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• pp.221-225
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• 2012

Disc dislocation without reduction, as known as closed lock, is a clinical condition in which the disc is dislocated from the condyle and does not return to normal position during condylar movement When the condition of disc dislocation without reduction is acute, the initial therapy should include an attempt to reduce or recapture the disc by manual manipulation. When patients report a history of being locked for 1 week or less, manual manipulation is usually successful. In patients with a longer history, success rate tends to decrease rapidly. If the disc has been successfully recaptured, placing an anterior positioning appliance is recommended to prevent clenching on the posterior teeth, which would likely redislocated the disc. But it is hard to make an appliance immediately in the clinic because it takes too much time. And making an appliance using self-curing acrylic resin is not very popular because of its discomfort by odor and working time. Also, if the patient has resin allergy or is under orthodontic treatment, or if it is impossible to control behavior of the patient, it has been restricted to make an appliance immediately. Therefore, to supplement this disadvantages, we tried to confirm about successful short term use of temporary anterior positioning splint made by using putty impression material after manual manipulation in this study.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.2
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• pp.141-146
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• 2002

Purpose: Various treatment methods have been utilized for recurrent dislocation of the TMJ (temporomandibular joint). The purpose of this study is to define the effect of the eminectomy with discoplasty that had been performed in patients with TMJ luxation. Materials and Methods: Twenty patients (22 joints), whose diagnosis were TMJ dislocation were selected in 772 patients (871 joints) who had been underwent TMJ surgery between 1988 and 2000. The selected patients were divided into two groups. Group I (12 joints) was the habitual-luxation group which involves the recurrent TMJ dislocation patients. Group II (10 joints) was the open lock-history group which involves the patients who had more than two episodes of TMJ luxation and TMJ disorders. The history of TMJ luxation, maximum mouth opening and other TMJ signs and symptoms before and after surgery were reviewed. Results: In group I, one patient who had been underwent both TMJ operation had a intermittent locking, but it disappeared after post-operative 32 months. In group II, intermittent pain was present in one patient who had bruxism, but it was disappeared by splint therapy. No more TMJ dislocations and other pains were checked in other patients of group I and II. Conclusion: Eminectomy with discoplasty may be used to successfully treat the TMJ habitual luxation accompanied with abnormal condition of the disc-condyle complex.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.37
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• pp.17.1-17.5
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• 2015

Arthroscopy is useful to detect early changes in the temporomandibular joint (TMJ). Despite great advances in arthroscopy, many arthroscopic surgeries have now been replaced by arthrocentesis. We propose a simple diagnostic and therapeutic method having operative rigid ultra-thin arthroscopy with 16 gauge needle size combined with arthrocentesis.

• Journal of Korean Physical Therapy Science
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• v.5 no.4
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• pp.717-728
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• 1998

The Temporomandibural joint(TMJ) is one of the most frequently used joint in the body as $1,500{\sim}2,000$ times per day for the activities of chewing, swallowing, talking, yawing and sneezing. The TMJ are formed by condylar process of mandible and mandible fossa of temporal bone, separated by an articular disc. This articular disc divides into two cavities as upper cavity and lower cavity. The gliding movement occurs in the upper cavity of the joint, whereas hinge movement occurs in the lower cavity. The movements that are allowed at the TMJ are opening, closing, protrusion, retraction and lateral movement. A cause of TMJ dysfunction are capsulitis, internal derangement, osteoarthritis, rheumatoid arthritis, infection and inflammation near the joint, trauma on joint, ankylosis, subluxation or dislocation of joint, injury of articular disc, myositis, muscle contracture or spasm, myofascial pain dysfunction syndrome, dyskinesia of masticatory muscles, developmental abnormality, tumor, connective tissue disease, fibrosis, malocclusion, swallowing abnormality, wrong habits such as bite nail or hair, bruxism, psycological stress and Costen syndrome etc. Assessment of TMJ dysfunction consist of interview, observation, functional examination, palpation, reflex test, joint play test, electromyography and radiologic examination and behavioral and psycological assessment etc.

• Journal of Oral Medicine and Pain
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• v.31 no.4
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• pp.337-346
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• 2006

Aims: The present study investigated the relationship between condylar resorption and craniofacial skeleton types(especially vertical relationships), the differences of craniofacial skeleton types between with open bite group and without open bite group, and the associations of anterior disc dislocation with or without reduction to condylar resorption with MRI. Patients selection and methods: Clinical examination, magnetic resonance imaging (MRI), panorama, lateral transcranial and lateral cephalometric radiographs in 34 patients with condylar resorption were used to investigate this relationship. Results and Conclusions: Patients with the following specific facial morphologic characteristics appear to be most susceptible to condylar resorption: (1) females were predominant, (2) patients' age ranged from 12 to 50 years old with a strong predominance for 2nd and 3rd decades, (3) patients had high mandibular plane angle and high gonial angle, (4) patients had decreased vertical height of the ramus, (5) patients had generally significant antegonial notch, (6) patients had predominance of Class I occlusal relationship with or without open bite but mandible was retruded as mean ANB 5.54 degrees, (7) condylar resorption rarely occurs in lower mandibular plane angle facial types, (8) although no statistically significant difference was found, the open bite group had a tendency more hyperdivergent skeletal pattern than the non open bite group, and (9) imaging demonstrates from small resorbing condyles to idiopathic condylar resorption and TMJ articular disc dislocations. Thus, morphologic features of patients with vertical discrepancies may represent a risk factor for the development of condylar resorption.

• Journal of Wind Energy
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• v.10 no.4
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• pp.20-27
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• 2019

High-speed shaft coupling in a wind power system transmits power and absorbs variations in length and spindle dislocation between the gearbox and generator. Furthermore, the coupling has an insulation function that prevents electrical corrosion caused by the flow of the generator's current into the gearbox and prevents overload resulting from sudden power failure from being transferred to the gearbox. Its design, functions, and part verification are described in the IEC61400 and GL Guidelines, which specify that the part must have a durability life of 20 years or longer under distance variation and axial misalignment between the gearbox and the generator. This study presents the design of a high-speed coupling through composite stiffness calculation, structural analysis, and comparative analysis of test and theory to identify the characteristics of high-speed coupling for a large-capacity 6 MW wind power generator. A prototype was fabricated by optimizing the manufacturing process for each part based on the design, and the reliability of the fabricated prototype was verified by evaluating the performance of the target quantitative evaluation items.