What is the best way to restore a chin and jawline that has thinned with age?

 Fat grafting is definitely an option. There are some benefits and downfalls to that. Honestly, some fillers do a good job for exactly this. Radiesse for instance does have some permanent qualities.    Implants are becoming less and less common because of the infection risks and the incision required to place them.  

 Hope this helps,

Best of luck,
DrC

Estuht.  Fat transfer from the tummy or thighs to the face is an excellent option for people of all ages. Younger patients can enhance their cheekbones or lips with fat that is natural and long lasting. As we age, our face deflates, losing fat, causing sagging skin to look more obvious. Fat grafting to the face rejuvenates the face with biological filler, your own fat! I frequently use fat transfer to my facelift patients to enhance and prolong the result. Depending on the individual, one treatment does the trick, but sometimes secondary touch ups are needed.  Be sure to consult with a board certified plastic surgeon. Good luck!

I am unclear as to exactly what you mean by thinning. I suggest you get an in person consulation to determine exactly what is bothering you. If you feel there is excess skin on the jawline and chin area, then tightening procedures are available- they vary from non-surgical to minimally invasive to surgery. So the consultation will determine exactly what you need and what your expectations are.