Do you reach for a piece of gum without giving it a second thought? You're not alone. Billions of pieces of gum are sold every year, and for many people, it's simply a part of daily life. Gum is used as a way to freshen breath, ease stress, or keep the mouth busy between meals. But if you've been noticing jaw pain, headaches, or a clicking sensation when you open your mouth, your chewing habit could be the culprit.