The temporomandibular joint's (TMJ) articular disc, situated between the mandibular condyle's convexity and the articular tubercle's slope, is the most intricate synovial articulation in the human body. While the usual discal position as defined by magnetic resonance imaging (MRI) places the posterior discal band at the 12 o'clock position atop the mandibular condyle's maximum convexity, this discal disposition is altered in over 30% of the population without any accompanying physical symptoms. This denotes that rather than correcting the anatomical disc position, the treatment for discal displacement would primarily focus on symptom relief.

Up until 1975, the only treatment options for (TMJ) internal derangement were surgical procedures that involved either repositioning the articular disc or removing it. Arthroscopic lavage was first described by Ohnishi as a way to dissolve adhesions and remove the inflammatory mediators, which reduced the pain, increased the mouth opening, and increased the harmony between the mandibular condyle and the articular disc, even though their native anatomical relation was not restored. Nitzan et al. in 1991 described arthrocentesis as a conservative method for (TMJ) lavage that discarded the arthroscopic morbidity and the need for costly tools and primarily aimed to utilize the hydraulic pressure of the lavage solution to wash out the inflammatory mediators, and release the articular disc adhesions.

The direct injection of a therapeutic agent into a joint cavity is known as intra-articular injection. Which usually aims to relieve arthralgia, suppress inflammation, and enhance joint function.

Various therapeutic agents are being deposited intra-articularly, including corticosteroids, hyaluronic acid, platelet-rich plasma and fibrin, opioids, corticosteroids, anxiolytics, muscle relaxants, antidepressants, anticonvulsants, and nonsteroidal anti-inflammatory drugs (NSAIDs).

(NSAIDs) the direct inhibition of the cyclooxygenase (COX) conversion of arachidonic acid to prostaglandins has been used to treat inflammatory articular diseases.

Oxicam-derived Tenoxicam and Meloxicam are inexpensive and readily available (NSAIDs); frequently injected intraarticularly following knee arthroscopy and (TMJ) arthrocentesis by virtue of their sustained drug delivery and long-lasting inflammatory effect.

Tenoxicam is a nonselective (NSAID) that inhibits both COX-1 and COX-2. On the other hand, Meloxicam is a selective COX-2 inhibitor.

The study aims to design a randomized controlled trial that compares the effect of intra-articular injection of the non-selective (NSAID) Tenoxicam versus the selective COX-2 inhibitor Meloxicam after arthrocentesis on alleviating the clinical signs and symptoms of (TMJ) disc displacement with reduction.

Inclusion Criteria:

1. Patients of both sexes with an age range of 18-45 years.
2. Those patients with the radiographic interpretation of unilateral or bilateral (TMJ) anterior disc displacement with reduction with the clinical signs of pain, limitation of mouth opening, and TMJ clicking; Wilkes classification type II.

Exclusion Criteria:

1. Clinical or radiographic signs of disc displacement without reduction, osteoarthritis, or articular bony changes.
2. Previous (TMJ) surgery, arthrocentesis, or occlusal splints.
3. Any systemic disease affecting the temporomandibular joint's anatomy, mechanical function, or outcome of the proposed treatment.
4. Those Patients with a history of allergic reactions to any components of the injectable solutions.

An independent staff member will randomly allocate the patients into (Tx group) and (Mx group) after labeling them