Injectable fIller for forehead (hairline area)? (Photo)

From the photo below you can see that there is a bit of a "jump" upwards in my skull where there is a steep slope and the hair grows out at different angles. Its not a huge issue but it results in an awkwardly shaped hairline and forehead, and ideally I would much rather have a flatter more round hairline and forehead shape. I was wondering if a simple addition of injectable filler to the area to reduce the steep drop off could be done or if more complex surgery is needed? Thanks for any advice!