Since you have consulted dentist for your complaints and he is telling that you are fine .
This condition has multiple causes and dental cause is one among them being most common .
Any other symptoms you have example chest pain or sleep disturbances or having exam pressure at home ,college or uni.?Rule out everything .Move away from stress ,cold and anxiety .Do u get nightmares ?Do u clench teeth when in stress or grind teeth in sleep ?
Next Steps
Now as this seems to be not that major issue unless you don't have previous history of chest pain .
Health Tips
Stop eating excess chewing gums and avoid trauma to it.
Warm water compression .
Drink 2litre/day fluid .
Tab pantop 20 mg OD 1/2HOUR before breakfast for 5 days .
Cap cobadex czs OD .
Tab ibuprofen plus BD for 1 day and then SOS
If pain not reduced consult orthodontist .