Hello and thank you for the question.
Facial fat transfer, when performed by an experienced surgeon, produces very predictable results with exceptionally low morbidity rates. Inhibited facial mobility following fat transfer is an extremely rare sequelae of this procedure.
I would recommend consulting with a Board Certified Plastic Surgeon or Facial Plastic Surgeon that is well versed in complex facial fat transfer.
Glenn Vallecillos, M.D., F.A.C.S.
Web reference: http://www.BeverlyHillsCosmeticSurgeon.com