Inclusion Criteria:  TMJ with audible and palpable click. Patients with anterior disc displacement as detected by MRI. Presence of full or nearly full complement of natural teeth.  Exclusion Criteria:  Patients who have radiographic evidence of degenerative conditions of TMJ. Patients who have anterior disc dislocation without reduction. Previous history of TMD treatment. History of recent trauma. The presence of systemic diseases (i.e. rheumatoid arthritis, osteoarthritis). Inability or unwillingness to undergo magnetic resonance imaging (MRI) such as implanted electronic devices. Pregnant and lactating females. Patients with known allergy to botulinum toxin type A. Patients suffering from neurological disorders.