Hair in dreams is used to symbolize the thoughts that come from the mind. As it is obvious that you are consciously aware that your head is shaved, the dream can imply that you could at least try to image yourself sporting a full head of hair.
Baldness in dreams would indicate that the thoughts that might be expected to be forthcoming in a situation, are simply not there. Thus a full head of hair in your dream, can also be saying that when living in your own Dream World - where fantasy, imagination or emotional thinking prevails - you are able to see your thoughts coming forth as a situation might call for. But - reality does not seem to back this up as your hair only grows in sparsely when you do attempt to let it grow.
The dream can be highlighting a need to pay more attention to how you are thinking about life situations. You might be ignoring issues or not putting the facts together correctly. Our physical body (and its hair)do reflect how we think.