Background: The temporomandibular joint (TMJ) is a highly intricate and complex synovial joint found in the human body. When TMJ dysfunction occurs, it causes pain and difficulties in opening the mouth, significantly impacting the patient's quality of life. Internal derangements, characterized by the gradual displacement of the articular disc, stand out as the most prevalent intra-articular temporomandibular disorders. Temporomandibular joint arthrocentesis, a procedure utilizing different irrigating solutions, is acknowledged as an efficient therapy for managing internal derangements of the TMJ. Recently, ozone therapy and orthobiologics like Platelet rich plasma (PRP) have been attracting increasing attention worldwide due to their promising medical applications and diverse therapeutic benefits in management of joint dysfunctions.

Aim of this study: The aim of the study is to compare the effectiveness of temporomandibular joint arthrocentesis using ozonated water combined with platelet-rich plasma (PRP) injection versus ozonated water alone for treating Wilkes stages III and IV of anterior disc displacement in terms of pain score, maximum mouth opening, and range of motion. Additionally, the study aims to compare the impact of both treatments on the concentration of the proinflammatory cytokine interleukin-6 (IL-6) in the joint space.

Inclusion Criteria:

• Pain located in the affected TMJ, especially during opening.
• Joint noises.
• Limited mouth opening (less than 35 mm).
• Impeded lateral movement toward the unaffected side.
• Deflection toward the affected side in opening in cases of unilateral affection.
• Patient who did not respond to conservative management.

Exclusion Criteria:

• Patients receiving anticoagulation treatment or non-steroidal anti-inflammatory drugs within 48 hours preoperatively, corticosteroid injection at the treatment site within 1 month, or systemic use of corticosteroids within 2 weeks.
• Patients suffering from any systemic inflammatory (degenerative) joint disease, and bleeding disorders such as coagulation disorders, platelet disorders, vascular disorders, and fibrinolytic defects.
• Patients with overlying infection or cellulitis in preauricular region.
• Patients with condylar pathology (hypoplasia, hyperplasia or tumor).
• Patients with previous open TMJ surgery or previous joint fracture.
• Patients with normal disc positions as seen by the MRI and the limitation is due to another extraarticular cause such as zygomatic arch fracture or elongated coronoid process.