Is There Treatment for Scaphocephaly in a Four Year Old?

I asked our pediatrician many times about the shape of my sons head when he was an infant. The pediatrician would feel around his head and assure me it was just head shape. When my son was 2 we moved and our new pediatrician immediately identified my sons head shape with scaphocephaly and said there was nothing that could be done. Now my son is four and I cannot find a safety helmet for him to wear properly to participate in sports/bicycling/etc. Is there help for him?