Anonymous wrote:OP here - Thanks for the helpful replies. To answer the question about what he understands the problem to be, he says it's just a habit. He eats with his mouth open and is extremely loud, but he says he can control it when prompted.
For context, he used to not be able to control it at all... so all the SLP and OT and PT since the age of 12 months seemed to have worked to help him move his tongue and facial muscles. A couple of years ago, he could not control his tongue at all and it just flailed about if he tried to stick it out.
So... he seems to have the ability right now. I think it's the ADHD that makes him lose focus on it (it's obviously pretty boring to think about how you're chewing) and habit formation.
It also likely takes him more effort than it takes someone else. Most of us don't have to consciously think about controlling our mouth and tongue, but it sounds like it's still effortful for him, even if now it's possible. I would give him only one thing to focus on -- chewing with his mouth closed is probably the biggest priority -- and ask him what support he thinks would be helpful.