Diagnosis of retrodiscal tissue in painful temporomandibular joint (TMJ) by fluid-attenuated inversion recovery (FLAIR) signal intensity.

AIMS: The purpose of the present study is to analyze the fluid-attenuated inversion recovery (FLAIR) signal intensity of the retrodiscal tissue in a painful temporomandibular joint (TMJ), and to develop a diagnostic system based on FLAIR data. METHODOLOGY: The study was based on 33 joints of 17 patients referred for MR imaging of the TMJ. Regions of interest were placed over retrodiscal tissue and gray matter (GM) on FLAIR images. Using signal intensities of GM as reference points, signal intensity ratios (SIR) of retrodiscal tissue were calculated. SIRs in painful TMJ were compared with those in painless TMJ. Wilcoxon's Rank Sum Test was used to analyze the difference in SIRs between the painful and painless groups (P<0·05). RESULTS: The SIRs of retrodiscal tissue were significantly higher in painful joints than in painless joints. CONCLUSION: FLAIR sequences provide a high signal in patients having painful TMJ, and it suggests that retrodiscal tissue in painful TMJ contains elements such as protein.

Two cases of posterior open bite caused by the thickness of retrodiscal tissue in the temporomandibular joint.

There have been few reports of mouth closing disturbances in the final phase of occlusion caused by the posterior thickness of the retrodiscal tissue. Two such cases are described here. The first was a 70-year-old female suffering from a painless mouth closing disturbance on the right side of the temporomandibular joint (TMJ). She complained of a feeling like there was an air cushion. The second case was a 51-year-old male with a painless mouth closing disturbance on the left side of the TMJ. In both cases, magnetic resonance imaging (MRI) revealed enlargement of the posterior joint space on the affected side. The conditions of these two cases were improved by local injection of steroid preparations; however further additional treatments were required, including mandible traction in one case and dental prosthetics in the other. Consequently, we consider that the local injection of steroid preparations is useful as an initial treatment, while the use of local injection of steroid preparations alone is not sufficient for the treatment of posterior thickness of the retrodiscal tissue.

A research for the relative signal intensity of the retrodiscal tissue in the temporomandibular joint disorder patients on MRI

The relative signal intensity of retrodiscal tissue in TMJ using a T2-weighted MRI

Relative signal intensity of retrodiscal tissue in mri, and synovial fluid concentration of interleukin-6, mmp-2 and mmp-9 in temporomandibular joint disorder

In the progression of the Temporomandibular Joint Disorder(TMD), not only deformation and perforation of disc occur. But also fibrotic adhesion and inflammatory changes to the retrodiscal tissue can be seen in addition to the condylar degenerative change (e.g. osteoarthritis). However, the correct diagnosis,?planning for appropriate treatment, and prediction of prognosis are limited, because there are no means to stage the progression of the disorder. In this study relative signal intensity of retrodiscal tissue in MRI and the synovial fluid concentration of matrix metalloproteinase-2 (MMP-2), MMP-9, and Interleukin-6 (IL-6) in the 23 temporomandibular joints(TMJ), from 17 patients with TMD were evaluated as a possible diagnostic marker. The relative signal intensity of retrodiscal tissue was referenced to brain gray matter with same region of interest(ROI) size. The concentrations of MMP-2, MMP-9, and IL-6 were evaluated by Enzyme Linked Immunosorbent Assay (ELISA). The collected data were compared with condylar degenerative change, joint effusion and disc position observed in MRI. The relative signal intensity of the retrodiscal tissue was increased significantly when degenerative changes were present. In addition, there was significantly high signal intensity in the presence of a disc displaced without reduction. The concentration of IL-6 was significantly increased when condylar degenerative change was no observed. And there were no changes in the levels of IL-6 according to disc position and joint effusion measurement. Moreover, there were no significant relevance between the concentration of total MMP-2 and active MMP-9 in synovial fluid, relative to degenerative changes in the mandibular condyle, to joint effusion, and to disc position observed on MRI images. In conclusion, the relative signal intensity of the retrodiscal tissue can be regarded as a mean of diagnosing the procession of TMD in a non-invasive manner. But more additional studies are required for the levels of MMP-2. MMP-9, and IL-6 to determine their potentials as a diagnostic marker for TMD.

The Mri-Based Comparison Of Normal- And Abnormal-Side Retrodiscal Tissue, And Relationship Between Clinical Examination & The Mri Findings Of Retrodiscal Tissue In Patients With Unilateral Tmj Internal Derangement

The study was performed to investigate the comparison of relative signal intensity of normal- and abnormal-side retrodiscal tissue, and relationship between clinical examination, joint effusion and relative signal intensity of retrodiscal tissue in patients with unilateral TMJ internal derangement. The study group comprised 19 females and 9 males, with a mean age of 29 years. After measurements of the signal intensity were made on the MR imager for the T2 weighted images on retrodiscal tissue and brain gray matter, we calculated relative value and tried to find relationship between clinical examination, joint effusion and relative signal intensity on normal- and abnormal-side. The results are as follows. 1. The gray matter is an appropriate reference point. 2. The relative signal intensity is high significantly in abnormal-side retrodiscal tissue compared with normal-side retrodiscal tissue. 3. The relative signal intensity is high significantly in painful joints compared with nonpainful joints and in joints with joint effusion compared with joints without joint effusion. 4. The relative signal intensity in normal joints, joints with reduction and joints without reduction is increased in order significantly.