Abstract: A mouth appliance that includes an upper tray having an outer wall, an inner wall and an occlusal wall that cooperate to define an upper teeth space, a lower tray having an outer wall, an inner wall and an occlusal wall that cooperate to define a lower teeth space, a tongue retaining member, and an extension member extending between the inner wall of the upper tray and the tongue retaining member.

Abstract: The oral appliance engages over the mandibular incisors and presents a flat raised upper contact surface which is sufficiently wide to contact at least part of one of the two upper center incisors and preferably both of them. This prevents tooth contact between the upper and lower dental arches to prevent grinding of the teeth. It prevents contact of the upper canine teeth with any teeth or the appliance so as to decrease the facial muscular tension which is sometimes associated with headaches and migraines. Application of the appliance to the lower dental arch is phonetically and aesthetically superior to other configurations and arrangements.