There are 2 indentations in my forehead. I recently just got the other 1. I never had chicken pox, trauma, acne or needling in this area. There is nothing underneath it like a cyst or tumor. I suspect it's something to do with sun exposure as I got a bit sunburned and this appeared right after the skin healed. But not positive because I couldn't find anything on the web in regards to that. What is the cause of this and the medical terminology for this? What are the treatment options? Thanks