The study will be carried out in Patients in two Groups aged between 17 to 70 years , of both sexes, who had painful symptoms, with or without presence of joint noise, and had unilateral or bilateral internal derangement of the TMJ proven by clinical examination, with no improvement after conservative treatment.

The MEASUREMENT TOOL of the study will be carried out by 2 groups the first will be injected by high molecular weight hyaluronic acid and the second wil be injected by low molecular weight hyaluronic acid Then compare between Efectevness of injection of high-molecular weight versus Low moecular weight hyaluronic acid after two-needle arthrocentesis in improving the signs and symptoms of intra-articular TMJ disorder.

, 1- significantly improving the pain on scale 1-10 , and 2-significant improvements in mouth opening range in mm by the distance between the edges of the frontal incisors with a ruler or caliper and joint noise.

3-The presence of absence of clicking and cracking in jaw .

Inclusion Criteria:

• Pain or tenderness of the jaw
• Pain in one or both of the temporomandibular joints
• Aching pain in and around your ear
• Difficulty chewing or pain while chewing
• Aching facial pain
• Locking of the joint,

Exclusion Criteria:

• Muscular TMJ disorders
• Bleeding tendency

The study will be carried out in Patients in two Groups aged between 17 to 70 years , of both sexes, who had painful symptoms, with or without presence of joint noise, and had unilateral or bilateral internal derangement of the TMJ proven by clinical examination, with no improvement after conservative treatment, were included in the study.