If the skin of your eyebrow has been injured seriously enough to leave a lasting scar, the hair follicles under it may have been permanently damaged or completely lost. Their access to nourishing blood may also have been cut off, as scar tissue normally has very limited blood supply. This happens often with thermal or chemical burns, severe infections, or deep cuts. Moreover, even if the hair follicles could produce hair, the scarred tissue may be too thick to allow it to grow through.  However, even if your hair follicles were accidentally destroyed, you may still have a chance to regain brow fullness with an eyebrow transplant. While this is not possible in every case, a trichologist can tell you whether you would make a good candidate for surgical eyebrow restoration.