Vertical line/indent in forehead. How can it best be treated? (Photo)

Hello. I have been distressed for some time about a vertical indentation in my forehead. Pictures reveal it has been there for some number of years now, but I can't help but think it is getting worse. I want to know what is causing this (is it linear scleroderma?), and how it can be best treated. My father has a similar indentation in his head and it makes me wonder if it some strange genetic feature? Thank you for your replies!