Yeah, I think the DNA appliance is dubious without any research or trials backing it up.
Actually a lot has been written since at least the 80s about how significant maxillary expansion is possible in adults even after age 25, but this is only because degree of suture fusion varies more than was once thought. So if your sutures haven't fused then you can achieve expansion. However other orthodontists have written extensively about how the suture can re-open under pressure from a palatal expander so there's that possibility too. It should re-open after a week and this can be determined using X-rays; however if it does not open after a week the appliance is removed and you are thought to not be able to achieve any further maxillary expansion without surgery. Even though the goal with palatal expansion is width, it has been observed that palatal expansion causes the maxilla to advance forward as well. No one has an explanation for that phenomenon other than chalking it up to force. I don't have the articles on hand but message me if you might like them and I can try to scrounge them up for you; they were heavily cited so they shouldn't be too hard to find. However I don't think most orthodontists will even attempt palatal expansion on an adult so you'd have to go to a doctor who really believes in it.
Thanks, Lefortitude, for your info as well!
