3 years ago my inferior alveolar nerve was severely damaged due to surgical trauma. Can nerve repair help the pain?

 Often it is possible to remove the metal plates. Usually this is done only for infection, pain or plates becoming obvious under the skin.I doubt the plates are the cause for the eyelid differences.  I recommend to see an oculoplastic surgeon or facial plastic surgeon for evaluation.

You might want to follow-up with your original surgeon to be evaluated.  A CT scan might help to determine how your bones have healed.  You may also have had some fat or volume loss following your accident.  If it is just a matter of some asymmetry between the two sides, you might benefit fro...

I do these pretty frequently. Make a 1 inch incision at the hairline, elevate right on the bone, chisel the osteoma off, smooth the area with drill (this is contouring but JUST of the osteoma region, not the entire forehead), stitch it closed nicely.