What Causes A Small Dent On Back Of Head?

Hello my concern is that i have a minor dent on the back of my head close to my neck i did not relize it until my fiance mention it to me i also have a small dent in the front of my head which looks like i had needles going thro my head i havr never been told by my family about any health condition when i was a child can you help me explain this or should i go to the hospital