Thanks for asking the query,
Swollen cheeks can occur due to many reasons few are;
Due to underlying dental issues, allergic reactions, inflammation of the lymph
nodes,inflammation of the parotid gland
known as Parotitis
, blunt trauma
to the face, persence of tumors , cysts.
Wisdom tooth that come croocked or crowd other tooth, or become impacted nay also leads to swollen cheeks.
It can be due to vitamin deficiencies, oral infections like bacterial, and viral.
I would suggest you to visit to an Oral and Maxillofacial Surgeon and get the clinical evaluation done, take an OPG radiograph.
Take vitamin tablets, maintain a good oral hygiene
Hope this helps out.