Abstract: An athletic mouthguard adapted for use by athletes and other persons engaged in physical activities which might result in occlusal or craniofacial stress. In one embodiment, the athletic mouthguard is a unitary structure which comprises a mouthpiece and an elongated strap adapted for attachment to the face mask of a helmet or the like. The mouthpiece, which is designed for use over the upper set of teeth of the wearer, includes an inner peripheral wall, an outer peripheral wall, and a connecting wall, the inner surfaces of which define a channel. The occlusal surface of the channel is more narrow in the anterior region and becomes more broad as one moves posteriorly so as to accommodate the non-uniform widths of the various teeth. In addition, the occlusal surface of the channel becomes progressively more concavely-shaped as one moves posteriorly from the first bicuspid tooth to accommodate the increasing convexity of the posterior teeth.