Evaluation Study of Retro Discal Tissue Injection Arthroscopically Versus Ultrasound Guide Injection

Inclusion Criteria: * Adults aged 18-60 years with symptomatic TMJ disorder/internal derangement (unilateral or bilateral) * TMJ pain at rest and/or during function for ≥ 3 months * Clinical diagnosis consistent with disc displacement with or without reduction (with or without MRI confirmation, if included in the protocol) * Baseline pain intensity ≥ 4/10 on VAS or NRS * Limitation of mouth opening or functional impairment (e.g., maximum mouth opening ≤ 35 mm or pain-related limitation) * Failed or insufficient response to conservative therapy for ≥ 4-6 weeks (e.g., soft diet, NSAIDs, splint therapy, physiotherapy) * Ability to provide informed consent and comply with scheduled follow-up visits Exclusion Criteria: * Previous TMJ surgery (arthroscopy or arthrotomy) on the study side or TMJ injection within the last 3-6 months * TMJ ankylosis, fracture, tumor, or active infection * Primary inflammatory arthropathy (e.g., rheumatoid arthritis, gout, psoriatic arthritis) or systemic connective tissue disease affecting the TMJ * Significant degenerative joint disease (advanced osteoarthritis) if the study focuses on internal derangement or soft tissue pathology * Severe skeletal or dentofacial deformity requiring orthognathic surgery during the study period * Pregnancy or lactation * Bleeding disorders, platelet disorders, or anticoagulant therapy that cannot be safely managed (particularly relevant for PRP injections) * Known allergy or contraindication to the planned injectate or local anesthetic * Severe uncontrolled systemic disease (ASA III-IV) or inability to tolerate anesthesia or sedation (for arthroscopy arm) * Active psychiatric or neurologic condition that may impair accurate pain reporting or follow-up compliance