Braces resulted in slim face. After getting them off I have chubby cheeks again. What procedure would slim them down? (Photo)

Thank you for the interesting question. It is difficult to answer, however, without a bit more information.  Has your overall weight fluctuated during this time? What age are you in each photo? We need to make sure we are not seeing weight or age-related pubertal changes before giving a good recommendation.

Hi @M00nLight - Thanks for the question and sharing the picture!! :)
 Buccal Fat Pad Removal will help slim your face. This 1 hour procedure involves a small incision about 2 centimeters long near the molars. No general anesthesia is required and patients are recovered in about 2-3 days.
At this time there is no laser, injection or facial exercise that can help with buccal fat pad loss. Some websites promote facial exercises and cardio workouts that promise to reduce facial fat. Others discuss a low salt, low carb and low alcohol diet. Unfortunately none of these can provide instant and permanent reduction in face fat like a buccal fat pad removal.  
The Buccal Fat Pads are natural pockets of fat that are in your cheeks. In childhood these fat pads serve to nourish and protect the muscles used in suckling for milk from a bottle or breast. These typically shrink with age, but if they remain large they can give your cheeks an overly chubby appearance. 
In fact, large buccal fat pads often will make others think you’re younger than you really are. Unlike fat in other areas of the body, buccal fat pads tend to be resistant to diet and exercise. 
Best of luck,
Dr. Chopra