Do cheek implants change as you age? Should I get fat grafts instead?

Thank you for your question. You are asking if cheek implants change as you age, and if you should get a fat transfer instead for cheek augmentation. You indicate you are only 19-years-old, but your cheek volume does not reach your nose when not smiling, making your nose look larger, and you find your cheeks to be flat.
I can certainly guide in the absence of a physical exam, and also without a photo for reference. I’m a Board Certified Cosmetic Surgeon and Fellowship-trained Oculoplastic Surgeon. I’ve been in practice in Manhattan and Long Island for over 20 years. I perform cheek implant surgery, often at the same time as a facelift, surgical fat transfers to the cheeks, as well as perform non-surgical cheek augmentation with fillers, using a special technique called Structural Volumizing.
To first answer your question, cheek implants do not change in shape as you age, however, the bone structure where the implants are placed certainly does. There is significant volumetric loss of bone, muscle, fat, and soft tissue as we age, so your face actually gets smaller. As bone diminishes with aging, the silicone cheek implants will eventually not fit properly, and the edges of the implant may be seen through the skin. While cheek implants to last long-term, they are not actually permanent because at some point they won’t fit your face.
You are asking if fat transfer is a better option. Fat transfer is an option, but you must realize that 30-70% of grafted fat can be absorbed by the body, so you will need at least two surgical procedures. Grafted fat is an unpredictable material to work with, due to absorption, not taking to a blood supply, or not retaining its desired shape, so additional surgery may be needed for best results.
The more predictable procedure I prefer for cheek augmentation these days is using a long lasting hyaluronic acid filler such as Juvederm Ultra Plus and Juvederm Voluma. These thicker fillers can last 1-2 years, and are designed for the cheeks, jawline, and other facial areas that have little to no movement. I place these fillers deeper, atop the bone structure and between the muscle layer, so they don’t migrate to look soft and doughy, but look natural and give structure to the face.
That said, you are only 19-years-old, so I would have to perform a physical exam to determine if you have a genetic volume deficiency in the cheeks and face before recommending any volume augmentation treatment. While it is possible you have one, it is often the case that people are a little overcritical with their own appearance, and see things in themselves that others don’t see. At 19, you are at the peak of your youthful appearance, so any procedure must be considered and evaluated carefully. I hope you found this information helpful. Thank you for your question.

Cheek implants structurally do not change over time as the material is stable. Whether in the very long-term when you are much older your overlying soft tissues will change around the implants to any significant degree is an often debated question. But in most cases with well placed cheek implants that are not oversized and fit the bone well, these are not issues of any consequence.