Imaging of the temporomandibular joint

Role of Dynamic 3 Tesla MRI in the Evaluation of Temporomandibular Joint Dysfunction

INTRODUCTION

The internal derangement of the temporomandibular joint (TMJ) is the most common type of dysfunction. Internal derangement can be divided into anterior and posterior disc displacement. Anterior disc displacement is the most common type, which is further classified into anterior disc displacement with reduction (ADDWR) and without reduction (ADDWoR). Temporomandibular joint dysfunction (TMD) symptoms are pain, reduced mouth opening, and joint sound. The main aim of this study was to correlate the clinical findings and magnetic resonance imaging (MRI) diagnosis of TMD in symptomatic and asymptomatic TMJs.

METHODS

This prospective observational study was conducted in a tertiary care hospital on a 3T Philips Achieva MRI machine with 16-array channel coils after obtaining approval from the institutional ethical committee. A total of 60 TMJs of 30 patients were included in the study. After the clinical examination of each patient, an MRI of both right and left TMJs was done. In patients with unilateral TMD, the asymptomatic side was used as the asymptomatic joint, and the affected side as the symptomatic joint. Asymptomatic patients without any symptoms of TMD were used as controls for bilateral TMD cases. MRI with high-resolution specific serial sections was obtained in both open- and closed-mouth positions. A p-value of <0.05 was considered a statistically significant agreement between clinical and MRI diagnoses of internal derangement.

RESULTS

Out of a total of 30 clinically asymptomatic TMJs, only 23 were normal on MRI. On MRI, 26 TMJs showed ADDWR and 11 showed ADDWoR. The most common shape of the disc was biconcave and the displacement was anterior in symptomatic joints. The most common type of articular eminence shape was sigmoid in ADDWR and flattened in ADDWoR. Agreement between clinical and MRI diagnosis in this study was 87.5% (p < 0.001).

CONCLUSION

 The study concluded substantial agreement between clinical and MRI diagnosis of TMJ internal dysfunction and suggests that the diagnosis of the internal dysfunction can be made clinically but the exact position, shape, and type of disc displacement can be assessed precisely with the help of MRI.

Diagnostic imaging: magnetic resonance imaging, computed tomography, and ultrasound

The temporomandibular joint (TMJ) is a synovial joint. The TMJ is a freely movable articulation between the condyle of the mandible and the squamous portion of the temporal bone at the base of the skull. The bilateral articulation of the mandible to the cranium implies that the left and right TMJs must act as a single unit. Physical examination alone is inaccurate in determining the status of the joint. The primary rationale for imaging the TMJ lies in the fact that mechanical internal derangement is treated differently from the multiple miscellaneous disorders. It is mandatory to have a correct knowledge of the joint anatomy and normal function that correlates with conventional and cross-sectional imaging studies. The TMJ is illustrated with an overview of imaging strategies and techniques, especially magnetic resonance imaging, computed tomography, and ultrasound.

MR imaging of temporomandibular joint dysfunction: a pictorial review

Temporomandibular joint (TMJ) dysfunction is a common condition that is best evaluated with magnetic resonance (MR) imaging. The first step in MR imaging of the TMJ is to evaluate the articular disk, or meniscus, in terms of its morphologic features and its location relative to the condyle in both closed- and open-mouth positions. Disk location is of prime importance because the presence of a displaced disk is a critical sign of TMJ dysfunction. However, disk displacement is also frequently seen in asymptomatic volunteers, so that other findings may be required to help make the diagnosis. These findings include thickening of an attachment of the lateral pterygoid muscle, rupture of retrodiskal layers, and joint effusion and can serve as indirect early signs of TMJ dysfunction. It is important for the radiologist to detect early MR imaging signs of dysfunction, thereby avoiding the evolution of this condition to its final stage, an advanced and irreversible phase that is characterized by osteoarthritic changes such as condylar flattening or osteophytes. Further studies conducted with the latest MR imaging techniques will allow a better understanding of the sources of TMJ pain and of any discrepancy between imaging findings and patient symptoms.

MRI in the assessment of internal derangement and pain within the temporomandibular joint: a pictorial essay

In this pictorial essay we aim to illustrate the normal temporomandibular joint (TMJ) and the common abnormalities of the osseous, cartilaginous and soft tissue components. These include disc (meniscus) displacement, deformities and perforations, abnormalities of disc and condylar movement, joint effusions, synovial proliferation, condylar deformity and erosions, degenerative change and abnormal retrodiscal enhancement.

Arthrocentesis of the temporomandibular joint in adult horses

OBJECTIVE

To develop a method for arthrocentesis of the temporomandibular joint in adult horses.

ANIMALS

7 equine cadaver heads and 6 clinically normal adult horses.

PROCEDURE

Fluoroscopy, contrast radiography, and computed tomography were used on cadaver specimens to locate the temporomandibular joint, identify externally palpable landmarks for joint access, guide needle placement into the joint, and illustrate regional anatomy. The arthrocentesis technique was performed on 6 live healthy adult horses to determine efficacy and safety of this procedure.

RESULTS

Externally palpable structures were identified as landmarks for temporomandibular arthrocentesis, including the lateral border of the condylar process of the mandible, the zygomatic process of the temporal bone, and the lateral pericapsular fat pad. Arthrocentesis was successful in all 6 joints in the live horses, and no complications developed.

CONCLUSIONS AND CLINICAL RELEVANCE

The technique identified will improve the ability to examine and treat the temporomandibular joint in horses.

Comparison of clinical and magnetic resonance imaging diagnosis in patients with disk displacement in the temporomandibular joint

OBJECTIVE

The purpose of this study was to validate the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) for the diagnostic subgroup of disk displacement with reduction, with magnetic resonance imaging used as a gold standard.

STUDY DESIGN

The diagnoses from the clinical examination of 78 joints in 39 patients, each with disk displacement with reduction in at least one TMJ, were compared with magnetic resonance imaging diagnoses. The readers of the magnetic resonance images were blinded to the clinical diagnoses. The data analysis included kappa statistics and calculation of predictive values.

RESULTS

The predictive value of the RDC/TMD for disk displacement with reduction was 0.65. For disk displacement alone-the movement of the disk on opening not being considered-the predictive value was 0.92. The diagnostic agreement between RDC/TMD and magnetic resonance imaging diagnoses for all joints examined was 53.8%. Most of the disagreement was due to false negative clinical diagnoses for asymptomatic joints.

CONCLUSIONS

A positive RDC/TMD examination is predictive for internal derangement but not reliable with regard to the type of disk displacement; such examination is therefore of limited value in determining the true disk position and its functional movements.