Healthy volunteers between 16 and 35 years of age who require removal of their third molars may be eligible for this study. Participants will receive an injection of a local anesthetic (lidocaine) in the mouth and a sedative (midazolam) through an arm vein before surgery. Before the tooth is removed, a small tissue sample (biopsy) will be collected from the gum tissue covering one of the lower third molars to be extracted. After surgery, a second biopsy will be taken at some point between just after surgery to the time when pain from the extraction starts to develop. These tissue samples will be analyzed for cyclooxygenase levels.