So I didn't have any radiation but still have this problem- yet another side effect that no Dr ever told me about.
I can just fit 2 fingers in my mouth or 12 tongue depressors. This thread has been really helpful- thanks
I'm doing the tongue depressor exersise about 3 times a day with no result yet

but it has only been a week since I started. CAn anyone give me an idea of how long it took you before you saw results? Will I ever be able to fit a big sandwich or burger in my mouth again lol!?!! Not to mention other activities requiring an open mouth