This study is designed to assess the impact of injecting sodium hyaluronic acid versus a chitosan-hyaluronate hybrid gel into the upper compartment of the temporomandibular joint (TMJ) as a treatment for anterior disc displacement without reduction. The study will include patients diagnosed with Stage III or IV TMJ internal derangement (anterior disc displacement without reduction), as classified by Wilkes, with diagnoses confirmed through clinical symptoms and MRI evaluations. Participants will be randomly divided into two groups, both undergoing TMJ arthroscopy. In the first group, 2 ml of chitosan-hyaluronic acid hybrid gel will be injected into the affected joints, whereas in the second group, 2 ml of hyaluronic acid (HA) will be administered. The study will compare and analyze outcomes in both groups, focusing on pain during TMJ function, clicking sounds, the extent of maximum mouth opening, and maximum lateral jaw movement.