There’s no keeping secrets from your dentist, according to Women’s Health Magazine.

“Dentists can discover everything from your bad habits to your favorite beverages simply by asking you to say, ‘Ahh!'”

Find out how a dentist knows if you’re pregnant, a nail biter, a former thumb sucker or a patient who flosses right before her dental visit:

Also, learn how your dentist can help identify other health issues:

“The mouth is the window to the body,” says David Silverstrom, D.D.S., of The Silverstrom Group in Livingston, New Jersey. “Often, diseases like cancer, anemia, and diabetes will first be identified by the dentist in a regular examination, and this saves lives.”