What do you do when you're having your teeth cleaned and the dental hygienist's boobs push against your head?

I’m talking about female dental hygienists. I just had my teeth cleaned so this is up front in my mind.
Imagine you are supine in the chair. She’s enthusiastically working on the tarter between #23 and #24. She positions herself to get a better angle of attack and her boobs rest on the top of your head. What do you do?
I freeze and don’t move a muscle. I pretend I don’t notice. I don’t want her to think I am a pervert.
What do female patients do under these circumstances? Do you move your head?