Hello Maria and welcome.
Thank you for your query.
Let me explain a few facts in regards to your sons injury
, and any injury in general.
Any injury (cut, lacerations
, etc.) to the skin triggers a healing mechanism in the body, which helps in the formation of a new layer of skin or what is called 'scar tissue'.
Scar tissue is connective tissue
(type of tissue) which is a result of fibrosis
(which is the repairing process). The only problem with this process is that, due to the fibrosis and the injury, most commonly the hair follicles (roots) are destroyed. Due to this regrowth of hair on a scar, is very rare, unless a few hair follicles were somehow not destroyed.
But, in the case of your son, as a few years have passed since the injury, if the hair follicles were retained or not damaged by the injury, they should have generated new strands of hair by now, which is not the case.
The best option for you now maam, should be to visit a trichologist (hair specialist) or a hair restoration
specialist, as are available in abundance in all major cities, around the world. A hair transplant
would be the simple solution to this problem, but as the affected site is an unusual one, only the specialist will be able to decide how this can be done.
I hope I have at least helped in pointing you in the direction.
Wishing you and your son the best in health and a beautiful life ahead.