• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1310-1315
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• 2003

Severe osteoarthrosis of the knee joint often requires total knee arthroplasty (TKA) to yield adequate knee function. The knee joint with TKA is expected ideally to restore the characteristics, however, this is not necessarily true in the clinical cases. In this study the motions of the intact joint and the joint after TKA were investigated numerically using computer simulation. For active knee extension from 90 degrees of flexion to full extension, the intact knee joint exhibited anterior tibial translation near the full extension while it showed only rotation for other flexion angles. Physiologic external rotation of the tibia near full extension was also noted in the analytical model. The analysis of the tibial insert of three different shapes (flat, semicurved, and curved types) demonstrated characteristic rotational and sliding motions as well as different contact forces.

• Imaging Science in Dentistry
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• v.35 no.2
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• pp.69-75
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• 2005

Purpose : To determine the clinical correlation of magnetic resonance imaging (MRI) findings of temporomandibular joint internal derangements. Materials and Methods : The MR images of 150 TMJs in 75 patients were analyzed. The clinical symptoms were pain in the preauricular area and masticatory muscles and TMJ sounds. Results : There was a statistically significant relationship between the MRI diagnoses of different types of disc displacements and clinical findings of pain, clicking, and crepitus. The risk of TMJ pain was increased when the disc displacement without reduction occurred at the same time in combination with the osteoarthrosis and effusion. Conclusion : Regardless of the results, the data indicate that each of these MR imaging variables may not be regarded as the unique and dominant factor in defining TMJ pain occurrence.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.9
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• pp.188-195
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• 2004

Severe osteoarthrosis of the knee joint often requires total knee arthroplasty(TKA) to yield adequate knee function. The knee joint with TKA is expected ideally to restore the characteristics, however, this is not necessarily 1.ue in the clinical cases. In this study the motion of the intact joint and the joint after. TKA were investigated numerically using computer simulation. For active knee extension from 90 degrees of flexion to full extension, the intact knee joint exhibited anterior tibial translation near the full extension and it showed only rotation at other flexion angles. Physiologic external rotation of the tibia near full extension known as screw home movement was also noted in the analytical model. The analysis of the tibial insert of three different shapes (flat, semicurved, and curved types) demonstrated characteristic rotational and sliding motion as well as different contact forces.

• Journal of Oral Medicine and Pain
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• v.30 no.1
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• pp.107-119
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• 2005

Temporomandibular joint arthritides is divided into osteoarthritis, osteoarthrosis and polyarthritis. Because the signs, symptoms and radiographical features of osteoarthritis and osteoarthrosis are similar without arthralgia, diffenential diagnosis is difficult. Also non-radiographically change in early Osteoarthritis leads to misdiagnose. Planar bone scan and SPECT are useful to detect bone change early. This study was carried out in order to make diagnostic criteria of planar bone scan and SPECT. Three hundred and four temporomandibular joints were examined with clinical examination, computerized tomograph, planar bone scan, and SPECT. The obtained results were as follows. 1. If temporomandibular joint simple uptake ratio of patient in twenties is over 1.397%, it's condition may be osteoarthritis. And simple uptake ratio over in thirties-fourties may mean osteoarthritis. 2. It may mean osteoarthritis of temporomandibular joint that the number of coronal and transverse SPECT frame with hot spot is over four. 3. Destructive stage may goes on, if simple uptake ratio is over 1.370% in tweenties and over 1.104% in thirties-fourties. 4. If the number of coronal SPECT frame with hot spot is over four, temporomandibular joint may be on destructive stage in tweenties, thirties-fourties. And if the number of transverse SPECT frame with hot spot is over three, it may be on destructive stage in all ages. 5. When patient complains subjective arthralgia and palpation arthralgia, bone change may be more active than each arthralgia. 6. Osteoarthritis may progress gradually worse in 4.5 anamnesis. And then it may be stable gradually and turn to osteoarthrosis.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.10 no.1
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• pp.47-55
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• 1980

The author analysed the routine radiographic changes and clinical symptoms of 205 cases of temporomandibular joint arthrosis. The clinical symptoms of the patients were classified and the morphological ylar head, articular eminence, and articular fossa were analized and discussed view point. The positional changes of condylar head and articular fossa relatation in TMJ arthrosis were observed. The frequencies of coincidence between the site of complaints and the site of the abnormal images which could be detected were examined. The results were obtained as follows; 1. Bone erosion, deformity, marginal proliferation and sclerosis were selected from many abnormal images as the radiographic diagnostic criteria of TMJ arthrotic lesions. 2. Abnormal radiographic findings were revealed in 150 cases (73.9%) of 205 total TMJ arthrosis cases and site with abnormal findings coincided with the site of complaints in 106 cases (70.7%) of 150 cases and coincidence rates were higher above fourth decades than below third decades. 3. Sclerosis of the abnormal radiographic findings could be found more often below third decades than above fourth decades. 4. The positional changes of condylar head were revealed in 176 cases (85.9%) of 205 total cases. 5. Pain complaints were revealed in 170 cases(82.9%) and clicking sounds were revealed in 120 cases (58.6%) of clinical symptoms of TMJ arthrosis. 6. No tendency was found so far the differential diagnosis between pain dysfunction syndrom and osteoarthrosis of TMJ.

• The korean journal of orthodontics
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• v.23 no.4 s.43
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• pp.645-660
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• 1993

In this study, effects of incision of retrodiscal tissue and unilateral occlusal reduction on temporomandibular joint of rabbit were investigated. Twenty-seven adult New Zealand White Rabbits, weighing over 3.5kg, were utilized in this study. Temporomandibular joint surgery was performed in left temporomandibular joint of 24 rabbits to displace disc anteriorly through incising the retrodiscal tissue 1-2mm posterior to the disc. They were divided into two groups : twelve were left untreated after surgery, occlusal reduction was performed on left posterior teeth every 2 weeks in the other twelve rabbits, The remaining three served as the control group. The sample were sacrificed by 8, 12, and 16 weeks after surgery. Histologic examinations were performed after sacrificing them. The results were as follows : 1. Histologic findings which were manifested by flat articular fossa, broad articular surface, generalized recession of articular cartilage and sclerosis of subchondral bone were observed. These findings were similar to internal derangement. 2. In the rabbits untreated after surgery, thin cartilagenous layer and necrotic tissue were observed in 8 weeks group, calcifying cartilagenous layer was observed in 12 weeks group, and cartilagenous layer on anterior portion was observed in 16 weeks group. So, it showed gradual healing pattern into the normal tissue except displaced disc. 3. Occlusal trauma after surgery resulted in generalized recession of upper and lower articular surface. Necrosis and vertical split on condylar process of mandible were observed in 8 weeks group. Osteoclasts, exposure of subchondral bone due to erosion on upper and lower articular surface, and degenerative changes on retrodiscal tissue were observed in 16 weeks group. So, it showed continuous prowess pattern of osteoarthrosis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.41 no.3
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• pp.125-132
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• 2015

Objectives: The purpose of this study was to clarify which findings in magnetic resonance imaging (MRI) are good predicators of pain and mouth opening limitation in patients with temporomandibular joint (TMJ) internal derangement (ID). Materials and Methods: Clinical examinations for pain and mouth opening limitation were conducted for suspected TMJ ID. MRI scans were taken within a week of clinical examinations. On the oblique-sagittal plane image, readings were obtained in terms of the functional aspect of disc position, degree of displacement, disc deformity, joint effusion, and osteoarthrosis. Multiple logistic regression analyses were conducted to identify the predictors of pain and mouth opening limitation. Results: A total of 48 patients (96 TMJs) were studied, including 39 female patients and 9 male patients whose ages ranged from 10 to 65 years. The resultant data showed significant correlations between pain and the MR imaging of the degree of disc displacement (P<0.05). The probability of there being pain in moderate to significant cases was 9.69 times higher than in normal cases. No significant correlation was found between mouth opening limitation and MRI findings. Conclusion: We identified a significant correlation between clinical symptoms and MRI findings of ID. The degree of anterior disc displacement may be useful for predicting pain in patients with TMJ ID.

• Imaging Science in Dentistry
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• v.31 no.1
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• pp.9-16
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• 2001

Purpose: To investigate bone and disc configuration on MR images in internal derangement related to age. Materials and methods: MR images of 150 TMJs in 107 patients were analyzed to determine the morphologic changes. Two groups were distinguished to be correlated with age. Group I consisted of TMJs that were diagnosed as having anterior disc displacement with reduction (ADDwR), and Group 2 consisted of TMJs that were diagnosed as having anterior disc displacement without reduction (ADDwoR). We assessed the configuration of the articular disc, degree of anterior disc displacement, and osseous changes of TMJs. Results: The third decade (83 of 150 joints) was most frequent in this study. In the ADDwR group biconcave discs was most frequent at all ages except fifth decade, but in the ADDwoR group deformed discs was most frequent at third and forth decades. In the ADDwR group slightly displaced discs was most frequent at all ages, but in the ADDwoR group severely displaced discs was most frequent at second decade, and the degree of disc displacement was increased with aging over 30 years of age. TM joints showed osseous changes in 17% of the ADDwR group, and in 30% of the ADDwoR group. MR findings of osseous changes of the TMJ were not found to be significantly correlated with age. Conclusion: The prevalence of deformation of disc, displacement of disc, and osseous changes of TMJ was higher in the ADDwoR group than in the ADDwR group. MR findings of disc configuration and degree of disc displacement were found to be correlated with age.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.4
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• pp.359-369
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• 2008

Purpose: Fractures of the mandibular condyle accounts for 15% to 30% of all the mandibular fractures and lots of complications are reported. Among these complications, condylar resorption is the most important one to be taken into account. The purpose of this study is evaluating condylar resorption pattern in relation to extracorporeal fixation technique. Patients & methods: Thirty four patients with 42 mandibular condylar fractures were retrospectively examined with an average follow-up of 18.5 months (6-66 months). Male/female ratio is 27 males (7 bilateral cases) and 7 females (1 bilateral case). Applicated surgical techniques were extracorporeal fixation via submandibular approach and extracorporeal fixation via intraoral approach. We compared radiographic views of post-operative periods with that of most long term follow up in 34 operated sites respectively. Result: There were 2 generalized condylar resorption sites and 3 partial resorption sites with clinical implications. Others (29 joints) showed good healing or satisfactory adaptive state of temporomandibular joints clinically. Radiologically, signs of partial condylar resorption and/or osteoarthrosis were diagnosed in 11 patients. But, 8 out of the 11 patients didn't show significant clinical symptoms, which means successful adaptive remodeling of the surgically located condylar head. Conclusion: From the above results, intentional ramal osteotomy, temporary detachment of the fractured condyle and extracorporeal fixation technique seems to be effective and useful in those cases of condylar fractures in which reduction of the dislocated condyle is very difficult or virtually impossible.

• Journal of Oral Medicine and Pain
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• v.40 no.1
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• pp.28-34
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• 2015

Purpose: The aim of this study is to assess the relationship between possible occlusal change after stabilization splint therapy and the research diagnostic criteria for temporomandibular disorders (RDC/TMD) Axis I diagnoses and lateral cephalometric variables. Methods: Clinical and radiographic records of 47 TMD patients wearing stablization splint were reviewed. The number of occluding teeth was recorded and lateral cephalogram was taken at pre-treatment and 6-month post-treatment. They were divided into two groups. The control group consists of patients with the unchanged number of occluding teeth throughout 6-month splint therapy (19 females and 4 males), and occlusal-loss group with the number of occluding teeth decreased (19 females and 5 males). The difference of RDC/TMD diagnoses and cephalometric variables were compared between two groups. Results: In the control group, RDC group I, muscle disorders, was 39.1% (9/23), group II, disc displacements, was 17.4% (4/23), group III OA, osteoarthritis/osteoarthrosis, was 73.9% (17/23), and group III pain, arthralgia, was 82.6% (19/23). In the occlusal-loss group, group I was 41.7% (10/24), group II was 41.7% (10/24), group III OA was 70.8% (17/24), and group III pain was 83.3% (20/24). The frequency of RDC groups was not different between two groups, analyzed by binomial logistic regression. Pre-treatment cephalometric variables were not different between two groups. However, articular angle, AB to mandibular plane and ODI decreased and gonial angle increased significantly in the occlusal-loss group, implying clockwise rotation of the mandible, between pre-treatment and 6-month post-treatment, while none of cephalometric variables showed any statistical difference in the control group. Conclusions: Change in the number of occluding teeth was not related to the RDC/TMD diagnoses. Cephalometric values changed only in the occlusal-loss group as a result of mandibular clockwise rotation. None of cephalometric variables before the stabilization splint therapy was statistically different between the control and occlusal loss group.