I wake up imn morning with a crust in my
Probably yeast infection.
Hello dear, welcome to Ask a doctor service.
I read your query and here is my.
The crust in one or both sides of mouth are most probably is an inflammation and infection caused by yeast.
Having not properly fitting dentures creates good conditions for it to develop.
You can wash it well and use nystatin cream over it.
Apply it for 2-3 times daily for at least a week.
Hope I have answered the question.
Let me know if I can assist you further.