Hi...the swelling is due to insufficient space for the wisdom tooth to erupt where the food often gets accumulated and causes infection.The condition is called as Pericoronitis.
Next Steps
Visit dentist immediately to avoid serious dental problems.
Health Tips
Add salt in luke warm water and gargle in the affected side for 4-5 times a day to get temporary relief.
Advised to do regular dental check up and teeth cleaning every 6 months.