Fat or filler
Hyaluronic acid fillers are the safest and most predictable products to place in the temples. The temples have a very important artery (temporal artery) that can have disastrous side effects if injected with product. Fat cannot be dissolved, while hyaluronic acid fillers can be treated with hyaluronidase. An experienced injector is key when injecting the temples, and if this is the first time a patient is receiving filler in the temple, a dissolvable material is safest.
Volume Loss in Temples and Lower Face
Fat or fillers are excellent choices for the temple. In the lower face I prefer Radiesse. There are multiple choices that should be discussed with your surgeon. There are advantages and disadvantages of each.
I'm not a fan of fat and even many of the fat 'experts' use Juvederm or other fillers!
While fat sounds attractive, the fact is that it is inconvenient for the patient and ends up being a short term solution in many ways. Hyaluronic acid fillers, such as Restylane, Perlane and Juvederm are easily reversible if issues occur and end up being easier over the long term. Fat can also cause issues if you gain or lose weight and is extremely unpredictable. I have had several patients who have gone elsewhere for fat injections, only to be unhappy.
So I would not do the fat and see how you do with that. Good luck!
Volume loss in temples and face.
I like fat for hands and lips which i have used for 35 years. However, for the face I prefer Voluma. Lines are best done with Belotero. Fat in the face can leave irregularities and lumps.
Both are methods that can improve the temple "hollow". I prefer fat grafting over fillers. There shouldn't be any "lumps" associated with fat grafting. It is very predictable. Fillers don't last very long, but they could be a first use. Fat grafting is natural and will be permanent. Complications can occur with any method.
Fillers for the Temple
My "go to" for the temples is a combination of Sculptra and Radiesse. One causes collagen stimulation and even gives the brow a slight lift when filling out the temple, the other provides support for long lasting and immediate volume. Fat is unpredictable and has been reported to cause blindness in some people getting injection in the periorbital area. The other fillers are safer and very predictable. I suggest seeing a formal consult with a cosmetic dermatologist of plastic surgeon with experience in full face rejuvenation with fillers. I wish you the best of luck, Dr. Emer.