Cheek retractors make you look and feel so utterly ridiculous that it’s hard not to laugh. When you are being administered laughing gas, it is impossible.
The gas always made me slightly out of my head. I found it hard not to giggle at the dentist and his assistant even during a regular exam. So, when they pried and propped open my lips and cheeks, I could only hold back the laughter for a few seconds.
I remember that they had trouble working on me because of it. I seriously could not stop. They had to stop the gas and switch it to pure oxygen. They waited for me to come down off my high, and then they were able to continue. Somehow, the cheek retractor had become a lot less funny.