an orthodontic arch expander joins to a mouthpiece proximate to the rear of the mouthpiece . the transparent mouthpiece has a desired arc that fits over the teeth of the upper jaw . the mouthpiece has two wings that join near the incisors and then become parallel and spaced apart around the molars . near the molars , an arch expander joins to the mouth piece . the arch expander has two telescoping shells with a threaded jack and cooperating springs . each shell joins to a corresponding wing of the mouthpiece . turning the jack lengthens a rod that pushes the shells outwards against the mouthpiece thus widening the maxillary arch without brackets or bands upon the teeth . an alternate embodiment has the arch expander attaching directly to the palatal bone through screws placed through a grommet at the end of each shell by an orthodontist or oral surgeon .