How long has it been since you've had your jaw and bite evaluated? Do you happen to grind your teeth at night, do you know? Are you holding the phone on one shoulder, or leaning on your hand in thought much? These things can cause a misalignment to your bite, and give headaches. It can also cause vision problems, sinus troubles too. If you can, have your tmj's evaluated by a DMD or a DDS who specializes in TMD.