The mind or the head is the maestro that controls one's thoughts, feelings, and behavior.
To dream about your head refers to your notion that human beings are the masters of the universe. This can include your perception about the world, yourself, your accomplishments, dreams and identity.
If you dream that someone is trying to rip off your head, it signifies that you're not thinking straight or seeing things as they really are. This may be due to lack of knowledge or denial. Face your fears because avoidance is only a pain killer, and the pain will eventually be back.