It’s not obviously just mechanical, like a burp to release gas pressure, or just psychological, like a yelp to express fear or excitement. A yawn is more like a sneeze or a hiccup, an involuntary ...

Even fetuses yawn, a new study shows. During the second and third trimester, fetuses yawn frequently, and those yawns can be distinguished in four-dimensional ultrasounds from other mouth-opening ...

Humans’ first experience with yawning happens in utero, says Matthew D. Epstein, M.D., associate medical director of the Atlantic Health Sleep Centers in New Jersey. Yet, Earth-side, the ...

Open your mouth wide, stretch the muscles of your jaw and upper body, take a slow breath in, and then exhale quickly. What have you done? You have yawned. Many animals, including humans, yawn. They do ...

Is it true that we yawn when our brains are deprived of oxygen? Most of us can feel a yawn coming on. The muscles in our jaw begin to tighten, our nostrils might flare, and our eyes might tear up as ...

It took four medical personnel to put Jenna Sinatra's jaw back in place. Her head was also wrapped so her jaw would stay shut. A New Jersey woman found herself dealing with an extreme case of lockjaw ...