What is the most appropriate diagnostic study for a patient with a stuck jaw, tenderness to palpation, and deviation to the right, accompanied by intermittent right-sided headache and jaw pain?

From the Guidelines

The most appropriate next diagnostic study for this patient is a contrast-enhanced magnetic resonance imaging (MRI) of the temporomandibular joint (TMJ). This patient is presenting with symptoms of jaw tenderness, deviation to one side, and unilateral headache and jaw pain, which are indicative of temporomandibular joint disorder (TMD) or possibly active TMJ arthritis. According to the most recent and highest quality study 1, contrast-enhanced MRI is currently the best method to detect active TMJ arthritis, with a level of evidence of 2 and a strength of recommendation score of 8.4 ± 2.1. This imaging modality provides superior soft tissue visualization to assess for disc displacement, internal derangement, or active inflammation. While a panoramic radiograph may be considered as a first-line study, the patient's symptoms and the need for detailed soft tissue evaluation make MRI a more appropriate choice. Additionally, the use of JIA-specific TMJ MRI protocols and scoring systems is recommended 1. Another study 1 also recommends MRI for TMJ ligament-capsule tissue disorders, which may be present in this patient. Therefore, an MRI of the TMJ is the most appropriate next step in diagnosing and managing this patient's condition.

Some key points to consider when ordering an MRI for this patient include:

• The use of contrast enhancement to detect active inflammation
• The importance of using JIA-specific TMJ MRI protocols and scoring systems
• The need for expertise in interpreting MRI findings, as the interpretation has an element of subjectivity
• The possibility of normal variations in TMJ fluid and/or minor contrast enhancement, which should not be misinterpreted as active TMJ arthritis 1.

Overall, an MRI of the TMJ is the best diagnostic study to evaluate this patient's symptoms and guide further management.

From the Research

Diagnostic Approach

The patient's symptoms, including a stuck jaw, tenderness to palpation, deviation to the right, intermittent headache on the right side, and pain in the jaw, suggest a temporomandibular joint (TMJ) disorder.

Imaging Modalities

To diagnose TMJ disorders, various imaging modalities can be used, including:

• Magnetic Resonance Imaging (MRI): considered the gold standard for imaging the soft tissue components of the TMJ, particularly for evaluating the articular disc and detecting early signs of TMJ disorders 2, 3, 4
• Computed Tomography (CT): useful for visualizing osseous changes and providing high-resolution multiplanar reconstruction of the TMJ, especially when MRI is contraindicated or not accessible 2, 5
• Cone Beam CT: provides high-resolution multiplanar reconstruction of the TMJ with a low radiation dose, making it suitable for evaluating the joint's bony structures 2, 6
• Ultrasonography: a non-invasive, dynamic, and inexpensive imaging technique that can be useful in diagnosing TMJ disc displacements, although its diagnostic value depends on the examiner's skills and equipment used 2

Next Steps

Given the patient's symptoms, an MRI would be the most appropriate next step to evaluate the soft tissue components of the TMJ, including the articular disc, and to detect any early signs of TMJ disorders 2, 3, 4. If MRI is not feasible, a CT scan could be considered as an alternative 5. It is essential to select the most suitable imaging modality based on the patient's specific condition and to consult an oral and maxillofacial radiologist if necessary 6.