Salt should play no part in you having a headache. Headaches come from the muscles in your neck and/or back. When those muscles get tight they send a message so intense to the brain that when it gets to the brain all it feels is pain, thus a 'headache'. If you get your front teeth knocked out that means you had to be hit there very hard and your head strains to keep itself upright and in doing that can stretch the muscles in the neck and get them locked in that stretched mode, a whiplash, to make it easier to know what it is. Once you release the muscles your headache will go with that. Here is how to release those muscles:
For your neck:
place your hand alongside your head and push your thumb in under your ear and place it on the muscle there. Take your fingers and place them on the back of your neck on the muscles there. Press them together and hold a good amount of pressure on them. Then relax, take a deep breath an happening, the muscle going limp under the pressure. Continue to hold until the entire muscle has gone limp.
Back:
Place your left hand on your left knee. Place your right hand over your left shoulder and with your fingertips find the muscle next to your spine. Press on it and hold. Relax, take a deep breath and exhale and don’t tense up any part of your body. After about 30 seconds there should be a release happening and when it does slowly lower yourself forward onto your right leg. If you can lean over the outside edge of your leg it will be better for your release. Continue holding for a total of one minute. Then release but rest your body there for one minute longer. Then reverse and do the right side.