Just try this out for Urself (not particularly related to Toothache):
Whenever U get prodromal(initial) symptoms of pain in any part of ur
Body; see from
which nostril r u exhaling air. Try to breathe from opposite nostril.
Concentrate on that. Hold the previous one until ur regular exhalation
happens thr' opposite nostril.
Feel the difference for Urself !!
Have a Nice Day.
Dr. Pankaj Pagariya