This is a case study of facial feminization surgery on a 39 year-old patient.
The patient in this case had had previous FFS, but felt that her forehead was still masculine. The surgery and techniques used are described in detail.
The patient was satisfied with the results, the authors say the forehead looks more feminine now, and measurements confirmed that the forehead changed. Looking at the before and after pictures, I can see a difference in one set of pictures, but I am not sure I would have identified the before forehead as masculine. In addition, in one set of pictures the hair style is different and covers part of the forehead.
As in many studies, this is written by the people who did the surgery so there is a possible bias in favor of thinking they did a good job.
Note – This article contains pictures of surgery.