Hi....there are many reasons that may lead to bad breath, there could be a possibility of impacted wisdom tooth that might be infected or any other kind of infection and if there is no dental cause than there must be some issue with digestion, so you have to get your check up done
Next Steps
fix an appointment with Dentist to rule out any dental cause of bad breath.
Health Tips
please do get an x-ray done for that particular tooth in which you had pain in may