Is It Possible to Shave off the Ridge in my Forehead?

Forehead contouring can take place with a variety of techniques which includes:Reshaping forehead boneUse of HA pasteUse of Forehead ImplantsA CT scan can be helpful to determine the thickness of your bone to ensure that there is an approprate margin of safety.

The surgeon evaluating you would be the best source of reference after reviewing the CT scan. There are many options ranging from burring down the remaining bone to using bone cement or HA paste as you have mentioned. This may need to be repeated if resorbed. 

 One would have to see the xrays to determine how much bone is left, how much the adjacent bone could be shaved, and how thin the remaining bone would be, etc.

The frontal bone can be shaved down with surgical burs. One must be very careful not to over shave the bone in the frontal area due to risk of exposing the frontal sinuses to skin flora, which could lead to chronic sinus infections. So only areas of solid bone can be contoured.

Reducing the forehead prominence can be performed with a burr but has to be done judiciously based upon CT scans or x-rays to determine the thickness of the bone. Underneath the anterior frontal bone is the sinus. If the sinus is invaded it can lead to infections and future problems.

The thickness of the forehead bone and specifically the outer table of the bone will determine what can be done. The last thing you need is an infection, inning of the frontal bone or infection of the frontal sinus underneath it.
To be course (no pun intended) this is similar to sanding and smoothing wood flooring. You need to know the thickness before you start to prevent going through.
Your Plastic surgeon or Neurosurgeon should be able to tell you.
Dr. P. Aldea

As Dr. Aldea has said, it all depends on the tickness of the outer layer of the bone in that region.  This varies by the patient and can be determined by your CT scans.  The last thing you want is to burr down into an underlying sinus!