This study will evaluate how well different medications work to relieve pain following third molar (wisdom tooth) extraction. Scientists believe that hormone-like substances called prostanoids contribute to pain following oral surgery. Prostanoids are produced by cyclooxygenase (COX) enzymes. This study will examine how different medicines inhibit the COX enzymes and reduce the amount of prostanoids, and thus the amount of inflammation and pain. The study will also look at genetic factors involved in the production of prostanoids and the response to pain medication. (Only the bottom two wisdom teeth are extracted for this study. Patients whose top wisdom teeth also need to be removed will have those teeth extracted, also free of charge, at least 2 weeks after the first surgery.)