Internal derangements of the temporomandibular joint. I. Clinical and radiological diagnosis

A New Approach to Improve TMJ Morphological Information from Plain Film Radiographs

The hard tissues of the temporomandibular joint (TMJ) can be assessed through radiographic imaging to provide information to assist in diagnosis and treatment. However, the quality of information gathered from such imaging is often less than desired due to the small size of the TMJ, the widely varying fossa and condylar morphology, and the surrounding dense osseous structures. These make a clear and undistorted radiographic image of the hard tissue of the joint technically difficult. It is postulated that, if the degree of inaccuracy of a given radiograph is known quantitatively and taken into account, the clinician will be able to make a better informed qualitative assessment of TMJ morphology. The aim of this study is: 1. to improve the qualitative information that can be acquired from routine clinical plain film radiographs of the TMJ; 2. to use quantitative data to test the novel Neural Network (NN) model; and 3. to statistically show the discrepancies between routine radiographic images and the actual joint. Linear measurements of excised TMJs and their radiographic images were used to train a multilayer perceptron (MP) type NN model to predict joint dimensions more accurately. Such a neural network, developed using a statistical software package such as SPSS (SPSS, Inc. Chicago, IL), functions as a computer software program and predicts joint dimensions with increased accuracy when radiographic measurements are entered into the program. The NN model described here predicts the actual linear distances of the TMJ more closely than radiographic measurements and is more reliable in assessing the TMJ morphology.

Comparison of ultrasonography with magnetic resonance imaging in the diagnosis of temporomandibular joint internal derangements: a preliminary investigation

OBJECTIVE

This study aimed to compare ultrasonography (US) with magnetic resonance imaging (MRI) with respect to the diagnosis of temporomandibular joint (TMJ) internal derangements.

STUDY DESIGN

The study group consisted of 23 patients with a chief complaint of TMJ discomfort who were tentatively diagnosed by means of head-neck examination as having TMJ internal derangements and a control group of 9 volunteers who had no sign of TMJ internal derangements. All the patients were then examined by means of MRI and US.

RESULTS

The results showed perfect agreement between MRI and US in the diagnosis of TMJ internal derangements (kappa = 1.000; P =.0001).

CONCLUSION

MRI and US can be used to define the disk and its position, as well as the presence of TMJ internal derangements.

Internal derangement of the temporomandibular joint: an audit of clinical findings, arthrography and surgical treatment

Forty seven patients who underwent double contrast video-arthrography followed by surgery for internal derangement of the temporomandibular joint were reviewed retrospectively. Of the 50 joints assessed, arthrography demonstrated 39 (78%) with irreducible meniscal displacement and 11 (22%) with reducible displacement. Clinical findings were found to be unreliable in demonstrating the degree of internal derangement: 49% of irreducible meniscal displacements presented with clicking and only 20% with loss of click. The importance of video-arthrography is emphasised. Surgery for internal derangement proved successful. It is proposed that patients who have clinical evidence suggestive of irreducible meniscal displacement and have disabling symptoms should undergo early video-arthrography and be offered surgical correction.

Semiquantitative SPECT imaging for assessment of bone reactions in internal derangements of the temporomandibular joint

The temporomandibular joints (TMJs) of 60 patients with arthrographically confirmed internal derangements and 30 volunteers were examined with single photon emission computed tomography (SPECT). Semiquantitative evaluation was done by forming a quotient from the counts of a constantly sized TMJ-ROI relative to the overall counts of the cranium. The TMJ/cranium quotient depended on the age of the subject, with younger patients showing a larger quotient than older ones. Normal joints were separated from the afflicted ones by means of a discriminant analysis. Sensitivity of semiquantitative evaluation was 78% (disc displacements with reduction) and 89% (disc displacements without reduction). Correct visual evaluation was made in 53% of the reducing and 75% of the nonreducing discs. Semiquantitative SPECT of the TMJs provides important information on the extent of osseous changes in afflicted joints and is suitable for follow-up of splint therapy. It may also be helpful as a screening method in detecting clinically normal joints before arthrography is carried out and in assessing the presumptive response to treatment with a splint.