In a matter of one year Bristol has a much more mature, grown up look, which I think is partly due to a nice weight loss and a little surgical intervention. Her chin is longer and more refined which is most likely the result of a chin augmentation which uses a chin implant to create the new look. Her lips also appear to be fuller which is possibly the result of an HA filler like Restylane or Juvederm. Her cheeks and neck are noticeably smaller which might just be the result of her weight loss or possibly buccal fat removal and/or liposuction.
I love her new look! I think whatever work she did have done was all in good taste and moderation. She looks refined and grown up and whatever the mechanism was used to rid herself of that baby fat it worked. Bristol is a woman. Wonder if Levi is going to come crawling back... Over Sarah's dead body!