Please visit dentist /pedodontist for further clinical examination as it's because of deep caries causing the trouble along with pain & swelling with the tooth /teeth in question?
Next Steps
visit dentist /pedodontist for the same
Health Tips
don't worry about it. don't apply balm or anything hot to the affected area. You can apply cold ice pack EXTRAORALLY to the swelling. Maintain oral hygiene by rinsing with lukewarm salt water after every meals .