• Imaging Science in Dentistry
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• v.36 no.1
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• pp.41-48
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• 2006

Purpose : To evaluate the reliability and clinical usefulness of ultrasonography in the temporomandibular joint (TMJ). Materials and Methods : Parasagittal and paracoronal 1.5 T MR images and 7.5 MHz ultrasonographs of 40 TMJs in 20 asymptomatic volunteers were obtained. Disc position using MR imaging was evaluated and the distance between the lateral surface of mandibular condyle and the articular capsule using MR image and ultrasonograph of 27 TMJs with normal disc position was measured and compared. Intraobserver and interobserver measurements reliability was evaluated by using interclass correlation coefficients (ICC) and measurement error. Also, the distance measured on ultrasonographs was compared, according to mouth position and disc postion. Results : The normal disc position was found in 27 of 40 asymptomatic joints. At the intraobserver reliability of measurement, ICC at the closed and open mouth position were 0.89 and 0.91. The measurement error was 0.4% and 0.5%. At the interobserver reliability, ICC at the closed and open mouth position were 0.92 and 0.81. The measurement error was 0.4% and 0.7%. At the TMJ with normal disc position, the distances between the lateral surface of mandibular condyle and the articular capsule measured on MR images and ultrasonographs were $2.0{\pm}0.7mm,\;1.8{\pm}0.5mm$, respectively (p<0.05). On the ultrasonographs, the distances at open mouth position were $1.2{\pm}0.5mm$ (p<0.05). At the TMJ with medially displaced disc, the distances at the closed and open mouth position were $1.3{\pm}0.3\;mm\;and\;0.9{\pm}0.2\;mm$ (p<0.05). Conclusion : The results suggest ultrasonography of TMJ is a reliable imaging technique for assessment of normal disc position.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.25 no.4
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• pp.337-349
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• 1999

The extracellular matrix(ECM) is a complex network of different combination of collagens, glycosaminoglycans, laminin, fibronectin, and many other glycoproteins including proteolytic enzymes. The composition and organization of the ECM contributes to the uniques physical or biomechanical properties of a tissue. Fibronectins(FN) are dimeric glycoproteins located on cell surfaces, in the matrix of connective tissue, and in blood. Fibronectins mediate cell attachment to collagen substratum and have been implicated in a variety of important biological processes, including embryogenesis and cell differentiation. The purpose of this study was to determine the effects of surgical induction of anterior disk displacement(ADD) on distribution of fibronectin in the rabbit temporomandibular joint(TMJ) tissues included the articular cartilage, disc, retrodiscal tissue, articular eminence using an immunohistochemical technique. The left TMJ was exposed surgically, and all discal attachments were severed except for the posterior attachment. The disk was then repositioned anteriorly and sutured to the zygomatic arch. The right TMJ served as a shamoperated control. Normal joints were used as a nonoperated control. Fourty-five rabbits were used for experiments in total. For fibronectin immunohistochemical study, eighteen rabbits (one normal group and 5 experimental groups, each group consists of 3 rabbits) were used. The experimental rabbits were sacrified after operation period of 2, 3, 4, 6 and 8 weeks on fibronectin. The obtained results were as follows ; 1. Fibronectin immunoreaction on all TMJ tissues(mandibular condyle, articular disc, retrodiscal tissue, articular eminence) in the normal rabbit was observed. Especially the reverse cell layer and proliferation zone of articular cartilage of condyle show strong positive reaction. 2. Depletion of fibronectin in the all TMJ tissues except hypertrophic zone of articular cartilage occurred at 2 weeks following induction of ADD. 3. The restoration of immunoreaction at 4 weeks was observed and a progressive increasing reaction at 6 weeks, 8 weeks also was found. Our study generally showed degenerative changes in TMJ tissues after ADD although TMJ tissues adapted or degenerated to abnormal loads and stress distribution according to the remodeling capacity of TMJ tissues.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.1
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• pp.1-7
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• 2009

Purpose: The purpose of this study is to investigate the therapeutic use of Hepatocyte growth factor(Adv.CMV.HGF) in temporomandibular joint disc defect. Materials and methods: Twelve New Zealand white rabbits, weighing 2.5 - 3.0 kg, were used in this experiment. Defects(2 mm in diameter) were created in their TMJ discs. Recombinant Adv.CMV.HGF with gelatin sponge($Gelfoam^{(R)}$) as carrier was implanted in the defects. We divided the rabbits into four batches according to the duration of the implantation - of 1, 4, 8, 12 weeks - and both left and right TMJ of each rabbit in all groups were used in the research : left joints were used as experiment group and right were control group. Each batch of rabbits was killed one, four, eight and twelve weeks after the experimentation respectively, and called Group A, B, C, and D. (Group A = 1 wk, B = 4 wks, C = 8 wks, and D = 12 wks) Results: The experimental group showed a significant increase in the number of chondroblasts and active cell differentiation at the margin of the defects. Compared to the control group, in the experiment group chondroblasts increased and chondrocytes showed a columnar arrangement, which is witnessed at the time of cell differentiation. Conclusion: This study supports the case that Avd.CMV.HGF may be useful in the repair of articular disc of the rabbit TMJ.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.2
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• pp.249-270
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• 1993

For understanding of anatomy, physiology, and diseases of human TMJ, it is required to evaluate quantitatively the movement of the disc and condyle head of mandible. The histologic section of cadaver TMJ were examined, and the magnification of the MR image and its details of anatomy were evaluated. And then a quantitative analytic method, by comparing the Sectograph and the MR image of vital human TMJ, was proposed. For this study, 15 subjects(Male, 24~35years) were selected from a prosthodontic examination randomly, and each subject’s five interocclusal rubber registration records were made on the ICP, and 5, 10, 15, and 20mmjaw opening positions. All subjects were radiographed with a Denar Quint Sectograph Image System(Denar Corp., USA), and imaged with a MRP-20EX MR Image System(0.2T, Permanent Magnet Type, Hitachi Medical Corp., Japan) using an 100mm diameter bilateral type surface coil. These images were traced on the acetate tracing paper, and analyzed In this study, the findings led to the following conclusions. 1. In comparison of the histologic section of autopsy specimen with the MR image at the same section, the size(dimension) of MR image was 70% of the real one. It was possible to recognize the shape of articular disc, anterior and posterior attachments, and adjacent soft tissues, because of the excellent reproducibility of anatomical structure. 2. When we compared the amount of joint space on MR image with that of joint space on sectograph, the amount of joint space on sectograph was significantly greater than that of joint space on MR image, except at the top of condylar head. 3. The position of minimum joint space on sectograph at intercuspal position didn't coincide with the middle position of articular disc on MR image, and was approximately in the anterior third of posterior band of articular disc. 4. The amount of condylar movement on MR image at opening movement was greater than that of articular disc movement. From Intercuspal position to 5mm jaw-opening movement, the condylar movement showed hinge one, and over the range 5mm jaw-opening it suggested hinge & translatory one. 5. In terms of area variation of articular disc measured on MR image in sagittal plane, the area of posterior band increased with increasing the amount of Jaw opening, but the area of anterior band decreased conversely.

• Imaging Science in Dentistry
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• v.32 no.4
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• pp.221-225
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• 2002

Purpose: To evaluate the relationship between internal derangement and osteoarthrosis in the temporomandibular joint (TMJ) using magnetic resonance imaging (MRI). Materials and Methods: One hundred and six MR images of TMJs in 53 patients were evaluated. Disc displacements and osseous changes of the TMJs were assessed. Lateral and rotational disc displacements were also evaluated on coronal images. Results: No significant differences in the frequency of osseous changes of the TMJs between disc displacement with reduction and disc displacement without reduction groups were found. The erosion of the condylar head and the sclerosis of the articular eminence were more frequent in the internal derangement group than in the no disc displacement group. The flattening was the most frequently observed osseous change of both the condylar head and articular eminence. Conclusion : The relationship between internal derangement and osteoarthrosis is obscure, but it is thought that both disorders adversely affect each other.

• The korean journal of orthodontics
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• v.24 no.2
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• pp.331-348
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• 1994

The purpose of this study was to investigate changes in the shape and ultrastructure of the articular disc of the rat mandibular joint with aging. Mechanical stress applied to the articular disc changes during neonatal, suckling, juvenile, adult and senile stages. Mandibular joints of 6 groups of rats(1-, 7-, 17-, 27-, 55-day and over-1-year groups) were removed en bloc and processed for light and electro microscopic study. The changes in the shape of articular disc were examined by light microscope in each group. Structural and ultrastructural changes in the articular disc were examined by light and electron microscope in each group. The results were as follows : In the 1-day and 7-day groups, the articular disc was long and slender in shape and the articular disc was not fitted with the shape of the mandibular fossa and condyle. However' after that time, the anterior and posterior portions of the articular disc were more bulged and the middle portion was shorter and biconcave. Thus the articular disc was well fitted with the shape of the mandibular fossa and condyle. The cell density decreased with aging. In the l -day and 7-day groups, the Golgi apparatus, rough endoplasmic reticulum and free ribosome, which are involved in the synthesis of intracellular and extracellular matrix, were developed. In the 17-day, 27-day and 55-day groups, not only the cell organelles involved in the synthesis of the intracellular and extracellular matrix but also the cell organelles involved in the remodeling of the extracellular matrix(i.e., finger-like cell process, lysosome and mitochondria)were well developed. With advancing age, intracytoplasmic microfilaments were more accumulated and condroid cells increased. In the over-1-year group, the majority of cells of the articular disc were chondroid cells. The majority of cytoplasmic compartment were filled with intracytoplasmic microfilaments and cell organelles were not developed. Therefore, metabolic activities of the cell was markedly reduced and cells contained structures enduring mechanical stress, and cells which were in the process of degeneration were observed occasionally.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.22 no.2
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• pp.351-364
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• 1992

Internal derangement of the temporomandibular joint can be defined an abnormal relationships of the meniscus relative to the mandibular condyle, articuar fossa and eminence. This may cause variable mandibular dysfunctions and pain. For diagnosis, arthrography, computed tomography and magnetic resonance imaging are used. In this study, the author reviewed 98 TMJs of 88 patients who were diagnosed as internal derangement througth inferior joint space arthrography at the department of Oral & Maxillofacial Radiology, Dental Hospita, Dankook university through 1986 to 1992. 98 TMJs consisting of 30 disc displcement with reduction, 48 disc displcement without reduction and 20 perforation were studied about clinical and radiological findings. The results were as follows: 1. Internal derangement was found most frequently in the 2nd 3rd decades and the average age of perforation was higher than that of disc displcement with higher than that of disc displcement with reduction. The sexual predilection was 2 times hiher in females. 2. The most frequent chief complaints were TMJ sound in disc displcement with reduction, pain and limitation of mouth opening in disc displcement without reduction and pain in perforation. The duration of the chief complaints was longer in disc displcement with reduction with than in preforation and disc displcement without reduction. 3. Reciprocal click was the most frequently TMJ sound in disc displcement with reduction. History of joint sound in disc displcement without reduction an crepitus in perforation was the most frequent one. 4. The average maximum opening was 45.4㎜ in disc displcement with reduction, 31.4㎜ in disc displcement without reduction and 33.8㎜ in perforation. 5. In the centric occlusion, posterior condylar position was the most frequent in disc displcement with reduction. posterior and concentric condylar position was frequent in disc displcement without reduction, concentric and anterior condylar position in perforation. At 1 inch opening, the same position to articular eminence was most frequently found in disc displcement with reduction, posterior position in disc disp1cement without reduction, posterior and nterior position in perforation was frequently found. 6. Bony changes, especially sclerosis and flattening, was most frequently found in perforation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.46 no.3
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• pp.174-182
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• 2020

Objectives: Joint injuries frequently lead to progressive joint degeneration that causes articular disc derangement, joint inflammation, and osteoarthritis. Such arthropathies that arise after trauma are defined as post-traumatic arthritis (PTA). Although PTA is well recognized in knee and elbow joints, PTA in the temporomandibular joint (TMJ) has not been clearly defined. Interestingly, patients experiencing head and neck trauma without direct jaw fracture have displayed TMJ disease symptoms; however, definitive diagnosis and treatment options are not available. This study will analyze clinical aspects of PTA in TMJ and their treatment outcomes after joint arthrocentesis and lavage. Materials and Methods: Twenty patients with history of trauma to the head and neck especially without jaw fracture were retrospectively studied. Those patients developed TMJ disease symptoms and were diagnosed by computed tomography or magnetic resonance imaging. To decrease TMJ discomfort, arthrocentesis and lavage with or without conservative therapy were applied, and efficacy was evaluated by amount of mouth opening and pain scale. Statistical differences between pre- and post-treatment values were evaluated by Wilcoxon signed-rank test. Results: Patient age varied widely between 20 and 80 years, and causes of trauma were diverse. Duration of disease onset was measured as 508 post-trauma days, and 85% of the patients sought clinic visit within 2 years after trauma. In addition, 85% of the patients showed TMJ disc derangement without reduction, and osteoarthritis was accompanied at the traumatized side or at both sides in 40% of the patients. After arthrocentesis or lavage, maximal mouth opening was significantly increased (28-44 mm on average, P<0.001) and pain scale was dramatically decreased (7.8-3.5 of 10, P<0.001); however, concomitant conservative therapy showed no difference in treatment outcome. Conclusion: The results of this study clarify the disease identity of PTA in TMJ and suggest early diagnosis and treatment options to manage PTA in TMJ.

• 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.28 no.2
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• pp.143-153
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• 2006

Temporomandibular joint(TMJ) ankylosis is characterized by the formation of bony or fibrous mass, which replaces the normal articulation. Ankylotic block formation causes reduction of mandibular mobility, particularly hindering mouth opening, due to a mechanical block of the condylar head in its roto-transfatory motion. Surgery in TMJ ankylosis treatment entails complete ankylotic block removal and subsequent arthroplasty, possibly with autologous tissue between articular surfaces or heterologous material to restore the anatomic structure and normal function. Temporalis myofascial flap holds great promise for the reconstruction of various maxillofacial defects. In more recent years, a pedicled temporalis myofascial flap has been advocated in TMJ ankylosis surgery. Advantages of the temporalis myofascial flap in TMJ reconstruction include close proximity to the TMJ, adequate blood supply from the internal maxillary artery, and its attachment to the coronoid process, which provides movement of the flap during function, simulating physiologic action of the disc. This study evaluated 8 patients(11 TMJs) affected by TMJ ankylosis. All patients underwent surgical treatment of the removal of the ankylotic block and subsequent interpositional arthroplasty with temporalis myofascial flap. Bilateral TMJ ankylosis was observed in 3 patients(6 TMJs), right-sides in 3 patients, left-sided in 2 patients. Epipathogenesis was traumatic in 6 patients(8 TMJs), ankylosing spondylitis in 2 patients(3 TMJs). In 3 patients coronoidotomy was underwent. Average follow-up was 16.8 months after surgery, with a range of 7 to 28 months. No patients underwent additional TMJ procedures after the temporalis myofascial flap. All patients showed a distinctive improvement both in articular functionality and symptoms. We found that temporalis myofascial flap is very valuable in reconstruction of TMJ ankylosis.