Your Jaw May Be to Blame for Your Headaches Updated for 2026 CMCL 6 years ago Biting your nails, chewing on pen caps, or chewing a lot of gum may be the cause of your headaches. Did you know? If you have any of those habits, you might have temporomandibular dysfunction (TMD). Related Video Posts Make CREPEY ARMS Look Smoother While Sleeping Use GLYCERIN This Way to Make Your Skin Look YOUNGER HARD STOOLS? Add 2 Spoonfuls of THIS to Breakfast