A dent in the skull after brain surgery may be from a bore hole. This shoudl be evaluated in conjucntion with your neurosurgeon. They may be able to use synthetic fillers to restore the normal contour. This can be done in conjunction with a plastic surgeon.
In general, volume loss in the temple region can be a sign of malnutrition or disease, so please get an evaluation from your primary care physician.
I have seen wonderful results restoring volume in the temple area using Injectable Fillers. My personal experience is with Silikon-1000. Several...
I find that the nasojugal grooves can be treated in several different ways. It can be undermined and released in a transconjunctival approach. It can also be filled with material like restylane.