I used to work for an orthodontist. He used upper expanders where you turned the key at home. The upper expander works by separating the palate at the center and letting the bone fill in. Not sure how a lower expander would work but I do know the lower arch does need to be expanded at times. I haven't worked in that field for awhile, I'm sure there are new treatments available. This is a long term commitment. Be sure you are comfortable with and confident in the orthodontist you choose. When I worked in an ortho office there was not a charge for that first exam appointment. Get several opinions from different orthodontist: ask to see photos and ask lots of questions.