Will a facial fat transfer adress asymmetry and volume loss from a previous parotidectomy?

I had a left superficial parotidectomy 10 years ago without a reconstruction flap. I had loss of volume and asymmetry after and has gotten worse over the years. Will a facial fat transfer help and if I do both sides of my face will they do more on my left side for balance? Also, I’m worried about hypertrophy from the fat transfer. Is it common?