Hi Well Rounded,
There are methods of making the back of your head more rounded. I would not recommend Juvederm or Restylane as it would require very large volumes and would be a temporary fix. Sculptra is used to add volume to the temporal area to give a rounder, more youthful appearance. Experts in micro-droplet Silikon-1000 injections have been able to attain permanent results.
Consult with a well qualified and experienced facial plastic or plastic surgeon for evaluation of your defect. There are both surgical and non-surgical options.
Good luck and be well.
Dr. P



