• Imaging Science in Dentistry
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• 제33권2호
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• pp.63-70
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• 2003

Purpose: To describe the MRI findings of the retrodiskal tissue in patients presenting with TMJ internal derangement and to correlate these findings with clinical and other MRI manifestations. Materials and Methods: One hundred eighteen joints of 63 patients with TMJ internal derangement were examined by MRI. Tl-weighted sagittal MR images taken in both closed- and open-mouth were evaluated for the presence of demarcation between disk and retrodiskal tissue, the presence of low signal intensity, and the depiction of the temporal part of the posterior attachment. The results were correlated with the duration of TMJ internal derangement, the presence of pain, and other MRI findings, including the type of internal derangement, the extent of disk displacement, the degree of disc deformation, and the presence of osteoarthrosis. Results: A significant relationship between the presence of low signal intensity in the retrodiskal tissue and other MRI findings was determined. Low signal intensity on the open-mouth view was observed more frequently in patients with disc displacement without reduction, severe disc displacement and deformation, and osteoarthrosis (p<0.05). The demarcation between disk and retrodiskal tissue, and the depiction of the temporal part of the posterior attachment(TPA) were correlated neither with clinical, nor with other MRI findings. Conclusion: This study suggests that low signal intensity in the retrodiskal tissue on open-mouth MR image can be indicative of advanced stages of disk displacement.

• 대한조선학회논문집
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• 제38권3호
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• pp.93-106
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• 2001

선체 구조에서 피로 손상을 받기 쉬운 용접 부위인 T형 이음부(T-joint) 및 호퍼 너클 이음부(hopper knuckle joint) 모델의 피로실험 및 선형탄성 파괴역학을 이용한 피로균열 진전해석을 수행하였다. 집중 응력(hot spot stress)을 적용하여 정의된 균열 개시수명(균열 깊이 1mm)을 기준으로 하는 통합된 S-N선도를 작성하였으며, 잔류응력을 고려한 피로균열 진전해석을 통하여 피로균열 진전수명을 정확히 예측할 수 있었다. 또한, 임의의 형상을 가지는 용접 이음부(weld joint)의 피로균열 진전수명에 대한 정량화의 가능성을 확인하였다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제48권1호
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• pp.50-58
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• 2022

Objectives: Osteoarthritis (OA) is the most prevalent and disabling joint disease in the world. Temporomandibular joint (TMJ) exercise is a widely used treatment and could be a beneficial and long-term tool for treating TMJ OA. The present study aims to evaluate the effects of therapeutic exercise in the conservative treatment of TMJ OA. Materials and Methods: A single-group experimental pre-post test was performed. We included patients who met the diagnostic criteria for TMJ OA. Outcome variables were pain intensity (visual analogue scale), functionality (Helkimo index), and structural changes (ultrasound). Follow-up periods were at months 1, 3, and 6. The intervention included a home-based program with thermotherapy, manual therapy, and therapeutic exercise during the entire follow-up period. Results: We included 15 patients and 26 joints, all women with a median age of 57 years (range, 49-62 years). Median change in pain intensity on joint palpation, mouth opening, and at rest at the first month was 47.5 mm, 51 mm, and 60 mm, respectively, and 48 mm, 49.5 mm, and 42.5 mm, at six months (P=0.001). The Helkimo index showed significant improvement in medians from baseline severe dysfunction (17 points) to minimal dysfunction at three and six months (2 points) (P=0.001). Ultrasound showed improved disc position. Conclusion: This study demonstrated significant improvements in pain, function, and joint disc position and represents a valuable tool for the long-term treatment of patients with TMJ OA.

• 대한물리치료과학회지
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• 제22권1호
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• pp.29-36
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• 2015

Purpose : The purpose of present study was to improve communication of pain expressing terms and pain intensity between patient and physical therapist, and initiated to objectify a measurement of subjective pain. Methods : Data were delivered to 249 people by a self-completion questionnaire, and analyzed 160 copies except for 87 mark error of the collected 247 questionnaires. The questionnaire included a question on 55 terms used to describe pain, the type of the pain, and pain intensity using VAS (visual analogue scale). Results : The results were as follows; 'Tight' was the most frequently being expressed term of muscular pain, subsequently to 'knot' and 'dull'. 'Tear' was the term representing the most strong pain of muscular pain, subsequently to 'rupture' and 'squeeze'. 'Stinging' was the most frequently being expressed term of neurologic pain, subsequently to 'get shocked' and 'wriggle'. 'Burn' was the term representing the most strong pain of neurologic pain, subsequently to 'sear' and 'get shocked'. 'Creak' was the most frequently being expressed term of joint pain, subsequently to 'peel' and 'out of joint'. 'Break' was the term representing the most strong pain of joint pain, subsequently to 'peel' and 'crack'. Conclusion : The objectification of pain terms will be used to help physical therapist to check the patient's pain.

• Journal of Oral Medicine and Pain
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• 제25권1호
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• pp.63-71
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• 2000

The authors assessed if there is a relationship between joint effusion and the presence of pain, and between joint effusion and disc displacement in 446 temporomandibular joints of 223 subjects who visited the Department of Oral Medicine, Kyungpook National University Hospital with the complaints of temporomandibular joint problem. The amount of joint effusion and the position of disc were determined from magnetic resonance images of the temporomandibular joints. The position of disc was classified into normal disc position, disc displacement with reduction (DDWR), and disc displacement without reduction (DDWOR). The amount of joint effusion was graded according to the extent of joint area of high signal intensity on T2-weighted MR images. These findings were correlated with one another and statistically analyzed. The results were as follows; 1. The incidence of temporomandibular joint pain Was higher in the joints with higher amount of joint effusion (P<0.001). 2. The proportion of temporomandibular joints with higher amount of effusion increased in the joints with more advanced articular disc displacement (P<0.001).

• Journal of Mechanical Science and Technology
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• 제16권2호
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• pp.182-191
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• 2002

The reliable stress intensity factor analysis is required for fracture mechanics design or safety evaluation of mechanical joints at which cracks often initiate and grow. It has been reported that cracks in mechanical joints usually nucleate as corner cracks at the faying surface of joints and grow as elliptical arc through cracks. In this paper, three dimensional finite element analyses are performed for elliptical arc through cracks in mechanical joints. Thereafter stress intensity factors along elliptical crack front including two surface points are determined by the virtual crack closure technique. Virtual crack closure technique is a method to calculate stress intensity factor using the finite element analysis and can be applied to non-orthogonal mesh. As a result, the effects of clearance on the stress intensity factor are investigated and crack shape are then predicted.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.921-927
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• 1996

The purpose of this study is to compute the stress intensity factors of various conditions in the cracked p! ate. The stress intensity factor of pin-loaded cracked plate is investigated using the finite element method. This paper is divided into the two parts. The first part is the contact analysis, and the second is to compute the stress intensity factors. In the contact analysis, the iterative method is used, and convergence of this method is presented. In the computation of the stress intensity factors of plate, the length of crack, clearance, and angle are considered

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.728-731
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• 2005

The objective of this paper is to perform measurements of vibration intensity of a coupled beam. The propagation of flexural waves generates the out of plane vibration of the coupled beam. The longitudinal waves are generated due to the mode conversion at the structural joint of the coupled beam. The propagation of longitudinal waves generates the in plane vibration of the coupled beam. In order to identify the direction of vibrational power on the coupled beam, the in plane vibration intensity as well as the out of plane vibration intensity needs to be measured. The cross spectral method has been implemented to measure the in-plane vibration intensity as well as out of plane vibration intensity. The results shelved that the experimental method can be effectively used to measure the in-plane vibration intensity as well as the out of plane vibration intensity of coupled beams.

• 한국터널지하공간학회 논문집
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• 제20권6호
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• pp.989-1002
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• 2018

암반 내 그라우팅은 불연속면 내부에 시멘트 그라우트재를 주입하여 주변지반을 강화하는 목적으로 사용된다. 현장에서 다상의 그라우트재의 주입 시 거동특성 및 주입경로인 3차원 절리면의 형태가 사전파악되지 않으므로 정량적인 설계가 어려운 분야중 하나이다. 따라서 현장에서의 그라우트 주입 거동특성을 나타내는 GIN (Grouting Intensity Number) 지표를 이용하여 주입 모니터링을 통해 적절한 시공관리를 수행하는 것이 최적이 방안이다. 본 논문에서는 그라우팅 주입 시 절리면의 거칠기 등급과 물시멘트(W/C)비에 따라 발생하는 압력의 손실을 전산유동해석을 수행하여 조사하였다. 절리면이 거칠수록 그리고 물시멘트비가 높을수록 주입 시 마찰저항은 크게 발생하였으며 해당 결과를 각 조건별 상관식으로 정리하였다.

• 국제물리치료학회지
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• 제9권2호
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• pp.1508-1512
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• 2018

This study was conducted to examine the effect of joint mobilization on forward head posture and to propose an effective method to improve correct body posture and balance. A total of eight patients from a Maitland-applied group (n=8) received mobilization therapy to increase the mobility of the cervical joint, with Maitland's movement grade III intensity for 30 seconds of treatment and 30 seconds of rest, for ten intervals, three times a week for four weeks. The craniovertebral angle (CVA) changes before and after the intervention with the Maitland technique were measured as $56.85{\pm}2.31^{\circ}$ before, $63.23{\pm}2.23^{\circ}$ two weeks after, and $64.98{\pm}1.27^{\circ}$ four weeks after joint intervention. There were significant CVA changes before and after the Maitland technique (P <.05). The results of this study suggest that the Maitland technique is useful for improving the head vertebral angle in patients with forward head posture.