Temporomandibular joint: morphology and signal intensity characteristics of the disk at MR imaging.

Abstract

Magnetic resonance (MR) imaging has been used in the temporomandibular joint (TMJ) primarily to define the disk position. This report examines altered morphology and signal intensity characteristics of the TMJ disk as they relate to the severity of internal derangement. Two hundred sixteen joints in 133 patients with a history of such derangement. were imaged with MR. Disk position, signal intensity, morphology, and the presence of osteoarthritis were determined for each joint. The normal disk was not anteriorly displaced and had a normal "bow-tie" shape. A grade 1 disk was anteriorly displaced and had a normal shape; a grade 2 disk was anteriorly displaced and had an abnormal shape. Forty (19%) joints were considered normal; none of these exhibited osteoarthritis. One hundred thirty-nine (64%) joints were grade 1; osteoarthritis was found in 17%. Thirty-seven (17%) were grade 2; osteoarthritis was found in 95%. All forty normal joints had high or intermediate signal intensity in the disk. Osteoarthritic joints had a higher percentage of disks with diminished intensity (P less than .0001). Severe or untreated osteoarthritis is known to be a complication of TMJ internal derangements; hence this grading system seems to correlate with the severity of internal derangement.

The effect of interocclusal appliances on temporomandibular joints as assessed by 3D reconstruction of MRI scans

“…This may partly explain why there was no incidence of disc displacement in the intercuspal position, contrary to what would have been expected. 11,15,19,22 There is evidence in the literature to suggest that disc displacement and/or intracapsular pathology can occur in the absence of symptoms and signs of TMPD. 15,19 The TMJ appears to display an adaptive capacity to remodel and continue to function without ideal disc position.…”

“…15,19 The TMJ appears to display an adaptive capacity to remodel and continue to function without ideal disc position. 11,22 Controversy exists regarding the relationship between signs and symptoms of TMPD and occlusal and psychological factors. 23,24 The belief of a multifactorial aetiology is currently held by the majority of researchers.…”

“…4 The ability of IOAs to alter disc/condyle relationships remains controversial. The literature suggests that 'normal' disc/condyle relations are reestablished after IOA therapy, 11 either by repositioning of the mandible or by recapturing of the disc. For this study the definition of 'normal' in the mouth-closed position was established by Drace and Enzmann in 1990.…”

“…10 The sensitivity and specificity of two-dimensional (2D) MRI to detect changes in disc position and irregularities of bone surfaces have been shown to be greater than 0.5 and 0.63 respectively. 11 However, the multiple 2D sections of MRI in shades of grey are difficult to assess and make it difficult to envisage the three-dimensional (3D) complexity and internal relationships of the anatomical structures of the TMJ.…”

Temporomandibular Joint Magnetic Resonance Imaging Analysis in Adults with Steinert's Myotonic Dystrophy

“…Evaluation of the anatomical shape of the articular disc was carried out according to the technique given by Helms et al, (1989) and was classified as conserved, altered, or not evaluable. In addition, its resonance signal and its position in relation to the mandibular head, in phases of close mouth in maximum intercuspidation and maximum aperture without pain were recorded.…”