Correlation Between MRI Findings and Clinical Improvement Following TMJ Injection With Hyaluronic Acid and Platelet-Rich Plasma

Temporomandibular joint (TMJ) internal derangement is one of the most common temporomandibular disorders and is characterized by an abnormal relationship between the articular disc and the mandibular condyle, resulting in pain, joint sounds, and limitation of mandibular movement. Although clinical examination remains the primary diagnostic approach, magnetic resonance imaging (MRI) is considered the gold standard for evaluating TMJ soft tissue structures, including disc position, joint effusion, retrodiscal tissue, and inflammatory changes. However, MRI findings do not always correlate with symptom severity or treatment outcomes, making their prognostic value uncertain.

Intra-articular injection therapy has become a widely accepted minimally invasive treatment for TMJ internal derangement. Hyaluronic acid (HA) improves joint lubrication, reduces inflammation, and provides chondroprotective effects, whereas platelet-rich plasma (PRP) contains autologous growth factors that may enhance tissue repair and regeneration. The combination of HA and PRP may provide both symptomatic relief and biologic enhancement of joint healing.

This randomized controlled clinical trial aims to evaluate the relationship between MRI findings and clinical improvement following a single intra-articular injection of HA combined with PRP in patients with TMJ internal derangement with reduction. Sixty adult patients aged 18-45 years who have persistent symptoms despite conservative treatment and MRI-confirmed internal derangement with reduction will be enrolled.

Before treatment, all participants will undergo a comprehensive clinical examination, including assessment of pain intensity using the Visual Analog Scale (VAS), joint clicking, and maximum interincisal opening (MIO), as well as MRI evaluation of the affected TMJ. Platelet-rich plasma will be prepared from the participant's own blood and mixed with hyaluronic acid for intra-articular injection into the affected joint.

Clinical evaluations will be performed at baseline and at 1 week, 1 month, 3 months, and 6 months after treatment. MRI examinations will be repeated at 6 months. The primary objective is to determine whether baseline MRI findings correlate with and predict clinical improvement after treatment. Secondary objectives include evaluating changes in pain intensity, maximum mouth opening, and joint clicking following HA and PRP injection.

The findings of this study may improve understanding of the relationship between imaging findings and clinical outcomes and assist clinicians in selecting patients who are most likely to benefit from minimally invasive intra-articular injection therapy for TMJ internal derangement.

Inclusion criteria

• 1. Patients age between (18 -45). 2. Early/intermediate stage according to (Wilkes classification). 3. Patients have painful joint, clicking sound, with or without limited mouth opening.

• Patients unresponsive to conservative treatment. 5. Patient's ability and desire to complete the treatment protocol and follow up visits.

• Patients with internal derangement with reduction confirmed by MRI imaging

Exclusion criteria

• 1. Patient with an inflammatory or connective tissue disease 2. Patient with previous invasive TMJ surgical procedure. 3. neurologic disorders 4. History of injection of any substance into the target TMJ during previous 6 months.

• Patient with history of bony or fibrous adhesion. 6. Internal derangement without reduction. 7. Patient with psychological problem