Suggest Treatments For A Dent On The Face

Hi I have a dent on my left side of my forehead very visible it starts at the beginning of my left eyebrow & it ends at the middle of my head. I had this for years now and im getting tired of wearing my hair to the side always covering half of my face. i dont know how this came up. could it be a fall or something? can it be fixed? i had my head scanned when i was younger and the doctors didnt find anything wrong?