The buccal fat pad is an encapsulated lump of fat which lies deep to the facial muscles but superficial to the buccinator muscle of the cheek. The buccinator muscle lies just beneath the lining inside the mouth in the cheek and its function is to move food between the teeth when chewing and it pulls the corner of the mouth back when grimacing. Infants have relatively large buccal fat-pads and it is probably important for suckling. However it does not keep pace with the growth of the face as we get older.
That said in some individuals it can stay relatively large and cause round cheeks which can be an embarrassment. In the right patient reducing the buccal fat pad can improve the contour of the cheek.This is done from inside the mouth and is a relatively quick operation to perform.It can be done under local anaesthetic as a day-case procedure.
Buccal fat pad lying on the buccinator muscle in the cheek
Before and after pictures of a patient who had her buccal fat pads reduced from inside the mouth to make her cheeks appear less rounded