The study aims to assess the outcomes of arthroscopic lysis and lavage procedure with and without single intra-articular injection of hyaluronic acid in managing patients with anterior disc displacement without reduction.

The research question that this study will answer is:

Does arthroscopic lysis and lavage combined with hyaluronic acid provide better outcomes in terms of pain intensity and maximum mouth opening compared to arthroscopic lysis and lavage alone?

Inclusion Criteria:

1. Adults above 18 years old.
2. Diagnosis of Disc Displacement Without Reduction (DDWOR) with limited mouth : eitherunilateral or bilateral based on the DC/TMD and confirmed with MRI
3. History of unsuccessful conservative treatment such as physical therapy, occlusal splints,or medications (e.g., NSAIDs, muscle relaxants) for at least 3 months.
4. Patients must sign the informed consent, understand the study procedures and potential risks, accept to volunteer in the study and be available to attend the follow-up visits.

Exclusion Criteria:

1. Degenerative Temporomandibular Joint Disorders (e.g., osteoarthritis, rheumatoid arthritis).
2. History of prior TMJ surgery (e.g., joint replacement, previous arthroscopy).
3. Severe Systemic Conditions (e.g., cardiovascular disease, autoimmune disorders, uncontrolled diabetes).
4. Active joint infection, acute inflammation, or presence of any condition that may increase the risk of complications from arthroscopic surgery or injections (e.g., local infection, uncontrolled bleeding disorders).
5. Pregnancy or Breastfeeding.
6. Patients with severe Psychological Conditions (e.g., severe depression, psychosis, myofascial pain disorder) or dental related pain will be identified at the initial assessment and referred for appropriate psychological, behavioural, or dental management prior to inclusion in the study.

This is a double-blinded randomized controlled trial. Participants, outcome assessors, and the statistician will be blinded to treatment allocation. Surgeons performing the procedures cannot be blinded due to the obvious difference in the injectable material.