Thanks for the replies

WOW Livinthedream, 20 Thanks for the tip on the Fess spray

No Marydean, no allergy Dr, at this point I'm reluctant for more poking, prodding and testing.
He regularly chew gum for sensory reasons anyway

We have been told to give him time to grow out of it, but without good hearing his schooling will be affected. To be honest I am sick of waiting for him to "grow out of things" So many things we've been told that for and it always got worse.
I'm sad and angry that there isn't much I can do for him. He already has a lot going on without this