Forehead asymmetry. How to fix it? What is the procedure and how long is the recovery? (photos)

Best to get in person evaluation. Also need CT scan of your head. Surgery should be possible. Likely needs bony drill.

The depression in your forehead needs to be worked up with a CT scan to see where the deformity exists and how best to correct it so see a plastic surgeon for a consult.

You have an area of forehead bulging that is due to bone deposition, possibly from trauma or natural development. That forehead bony bulge can be reduced by burring of the bone down to match better to the opposite side. Fortunately the bulge lies close to your hairline where an incision to do that surgery can be placed.

The bulge on one side of the forehead needs to be worked up for proper  diagnosis.It will probably need a CT Scan.Once the diagnosis is made then treatment can be planned

Good question.   The asymmetry or larger side is visible in your photo.   You did not describe your previous evaluation to determine the cause.  We do not like to assume anything ( its been there for 30 years).  You would need a recent ct scan to evaluate the skull and see exactly what is enlarged and why.  The ct scan will determine what your options are or if further tests are necessary. I would recommend consulting with a Plastic Surgeon with craniofacial training. You would need to check your medical insurance benefits for coverage of the evaluation and treatment.  The cost would be based upon what needs to be performed and that of course depends on the ct scan.  

It is unclear as to the appearance of your forehead. Possibly with the submission of photographs there might be some basis on which to comment .