Fat grafting is the procedure where your own fat stores are utilized to augment, rejuvenate or correct. Fat grafting can be used to augment the cheeks or lips or anywhere else augmentation is desired, correct tissue deficiencies or simply rejuvenate the mature or thin face for a more "refreshed" look.
Fat Grafting is also referred to as free fat transfer, liposculpture, lipostructure, Space Lift® and others.

Fat Grafting usually performed anywhere from 16 and up. Ask your surgeon what he thinks and what ages he usually performs this procedure on s it can be different from surgeon to surgeon. It certainly can correct "deficiencies" or create symmetry in younger persons as well as augmentation and rejuvenation in those who need it, regardless of age.

The surgeon will go over your desires with you and explain your options. He r she will discuss what can realistically be achieved through this procedure, discuss with you the risks and complications as well as determine the amount of augmentation you will need.
Not everyone is a great candidate for fat grafting so go over all of your habits, including if you smoke, your metabolism and activity levels. Ask to see photos of his or her patients and ask for a referral list sop that you may discuss your concerns or ask questions from the surgeon's own patients.

Excess fat is removed from stubborn, fatty pockets, treated and/or "spun" and gently inspected for viable and whole fat cells. The fat cells are carefully re-implanted using various techniques and you are sent home to care for your treatment areas as discussed at your preoperative appointment.

You can expect to be swollen, possibly bruised and a little sore. This is all normal and should be realized beforehand. Patients who know what to expect are often better informed, and well balanced afterwards and recover more easily s opposed to those who are not told what to expect. 
You will be instructed to take all of your medications on time, keep you treatment area immobile and allow proper healing. This includes no high impact exercise or activities for approximately 2-3 weeks, depending upon the extent of the surgery. Please discuss this with your surgeon as the treatment type and/or area changes the pre-operative protocol.

Depending upon what other procedure were performed and what the preferences unique to your own surgeon, you may or may not have sutures. Some surgeons remove fat with larger cannulas, some with smaller ones and even others with special hypodermic needles. It is necessary to ask your own surgeon as you may not even require sutures for your donor suite.
Incidentally, some lip augmentation with fat grafting may require sutures. Some surgeons use long "threads" of fat implanted in a line within the lips and may need a suture at the injection area.

You will see immediate results and it might appear too augmented for your taste, this is often the swelling and possibly "overstuffing" of the fat to increase longevity. However, not all surgeons overstuff so be advised of your own surgeons technique preference. The swelling will subside and you will usually be able to view your true results in 3-4 months although you may lose fat after that as your body either metabolizes it, the fat proved to be damaged or otherwise.

The risks for fat grafting are asymmetry, infection, fatty cysts, hematoma, fat embolism, seroma, permanent discoloration from the bruises and others.

It depends. There are unfortunately many factors involved and it is most certainly surgeon-dependent. Some surgeons are able to get 10% longevity and even other up to 90%! So research your surgeon carefully, determine the differences in technique and discuss with their own patients, the amount of augmentation or enhancement left after several months or even years. It really depends but yes it is very possible to receive permanent results. Just know that fat naturally is lost as we age - so permanency may depend on your definition of it. It may last you many, many years but will more than likely not last you the rest of your life as you age.