Thank you for your question. I'm glad you're already thinking about the pros and cons to this. I would think of fat as a permanent filler. It will provide a softer look, and yes, over time will drop with the rest of the skin containing it. Implants on the other hand are meant to replicate the architecture of bone underlying soft tissue. If stronger changes are desired, then I would favor an implant over fat. However, implants also come with the downside of a degree of bone resorption, as well as infection and migration risks. Again, there isn't a right or wrong answer, but choosing the best treatment will depend on your goals, as well as tolerance of the risks involved. I hope this is helpful, and I wish you all the best. -Dr. P