Abstract: A mouthpiece according to the teachings of the present invention is shown as including a lens-like brace integrally formed in the outer upstanding portion of the elongated shell and positioned on the outer surface of the anterior teeth for reflecting any blow to the anterior teeth and reducing the shock to the teeth. The mouthpiece further includes a thickened connecting portion overlying the biting surface of the posterior teeth to help prevent concussion and to lessen the shock to the Tempro Mandibular Joint in the event of a blow to either the jaw or head. Indentations are formed in the thickened connecting portion opposite to the biting surfaces of the user's upper teeth having a size and shape complementary to and for receiving the user's lower teeth to form an occlusal index for positioning the user's lower teeth helping to eliminate the trauma of a blow to the side of the jaw.