Lockjaw (trismus) is a painful condition that limits your ability to open your mouth all the way. It occurs when the muscles you use to chew spasm, meaning they can’t relax completely. The term ...

Dolphins are known for what appear to be big, contagious smiles. But do they actually, well, smile? The answer, according to a new study of dolphin play, is a resounding “maybe.” Dolphins use their ...

Falling asleep with our mouths open happens to all of us and many think it isn't such a big deal. However, there are some eye-opening things connected to open-mouth sleeping. Our facial muscles tense ...

Dear Eric: I play cards weekly with a group. One of the women sometimes chews gum during our games, noisily and with her mouth open. This is worse than fingernails on a chalkboard to me. Why do ...

When they meet, sarcastic fringeheads can get mouthy. These bug-eyed, bright-lipped fish often open their giant jaws to show off the psychedelic hues splashed across the inside of their mouths. And ...