M.H.
I do have experience w/ plagiocephaly and braciocephaly. My niece was born w/ torticollis and laid on one the same side of her head which gave her plagiocephaly. They put a helmet on her and it worked great.
Having witnessed this first hand I was on point when I had my second child. He was actually born w/ braciocephaly. (same as plagio, just slightly to the side..not straight flat in the back). He was so large in the womb that he got stuck in 1 position and came out like that. My ped. kept saying, it would straighten out on its own and it wasn't!! I changed his positions, didn't let him lay on his back much, he rolled to his belly and slept as soon as he could and I had him on the things to prevent palgiocephaly from birth. --IT WASN'T FIXING ITSELF I saw a cranial surgeon that wanted to cut his skull into pieces and re-shape it because he thought the helmets were a joke. I asked him to refer me anyway because my son also had a heart condition and I thought surgery was dramatic.
The helmet helped him as well. In time it will get a little better, but my understanding is you need to do it now or you miss the window. The casting is very difficult on the babies and it takes longer to work the older they are. He is on the very outside window of when they like to use them.
Also, tell everyone it doesn't always resolve itself. So please stop making those comments unless they have had a child w/ plagiocephaly. My cousin had me feel her sons head when I told her about my son. It was totally lopsided on one side. He had think hair so I hadn't realy noticed it. She always held him on the same side in her arms and it gave him it. It is bad enought that he won't be able to wear his hair buzzed or real short and he will definately know it is there.
It takes a while for insurance to go throught, have the helmet made and ect.. so if you are considering it you really need to get the process started.
Good luck on your decision!!