Efficacy of Intra-Articular Hyaluronic Acid Combination Injections for Temporomandibular Joint Internal Derangement: A Clinical and MRI Based Randomized Trial

Temporomandibular joint (TMJ) internal derangement is a common disorder associated with pain, joint sounds, and limitation of mandibular function. Although conservative treatment is considered the first-line therapy, some patients continue to experience persistent symptoms requiring minimally invasive intervention.

Hyaluronic acid (HA) is widely used for intra-articular injection because of its lubricating and anti-inflammatory properties. Platelet-rich plasma (PRP) has demonstrated regenerative potential through the release of growth factors that may promote tissue healing. Corticosteroids provide potent anti-inflammatory effects but may adversely affect cartilage with repeated use, whereas tenoxicam is a long-acting nonsteroidal anti-inflammatory drug with favorable analgesic and anti-inflammatory properties.

This prospective randomized controlled clinical trial will compare three treatment protocols:

Hyaluronic acid combined with tenoxicam Hyaluronic acid combined with platelet-rich plasma Hyaluronic acid combined with corticosteroid

Sixty patients diagnosed with TMJ internal derangement with reduction confirmed by MRI and unresponsive to conservative treatment will be randomly allocated in a 1:1:1 ratio to one of the three intervention groups. Clinical assessments will include pain intensity using the Visual Analog Scale (VAS), maximum mouth opening (MMO), and joint clicking at baseline, 1 week, 1 month, 3 months, and 6 months. MRI examinations will be performed at baseline and 6 months to evaluate structural changes within the joint

Inclusion criteria

• Adults aged 18 to 45 years. TMJ internal derangement with reduction confirmed by MRI. Early or intermediate disease according to Wilkes classification. Painful TMJ with clicking, with or without limited mouth opening. Persistent symptoms despite conservative treatment. Able and willing to provide informed consent and attend follow-up visits.

Exclusion criteria

• nflammatory or connective tissue disorders. Previous TMJ surgery. Neurological disorders. Previous TMJ injection within the last 6 months. Fibrous or bony ankylosis/adhesion. Internal derangement without reduction. Psychological disorders affecting study participation.