The proposed clinical trial will consist of two parallel studies. In the first part of the study, we will evaluate the analgesia and adverse effects of celecoxib, a COX-2 inhibitor in comparison to naproxen and placebo of patients with temporomandibular disorders (TMD). Celecoxib, is in oral anti-inflammatory and analgesic agent that acts by selectively inhibiting cyclooxygenase 2 (COX-2) and is not expected to cause the typical gastrointestinal, and platelet-related side effects associated with inhibition of the COX-1 enzyme. Decrease in pain, dysfunction and improvement in quality of life will be assessed at base line and after 6-week follow-up. Successful demonstration of an enhanced therapeutic effect or reduced toxicity may provide a basis for clinical use of selective COX-2 inhibitors in patients with painful TMD.