Prototype of mouth piece

A protective mouthpiece formed in a dental arch and comprising an outer wall, an inner wall and an intermediate web member therebetween, said mouthpiece having an "H" shape cross section defining an upper groove capable of receiving maxillary teeth and a lower groove capable of receiving mandibular teeth, wherein the portions of said inner and outer walls defining said upper groove are substantially equal in height and the portion of said inner wall defining said lower groove is shorter than the portion of said outer wall defining said lower groove, whereby said mouthpiece provides protection for maxillary and mandibular teeth without stifling of oxygen intake.