M.P.
Does anyone else, like his teacher or friends and family notice his ears are "off." Is his face "ugly?" What does his doctor say? Have gotten a second medical opinion about the way he looks?
Know that no one has symmetrical sides. My ears are uneven. One arm is longer than the other. My right hand has a noticably longer middle finger than my left. I have a mild spinal scoliosis not caught because looking for scoliosis wasn't done when I was a child. Where I've needed to adapt, adapting was just done with no thought from me or my parents.
I understand it's disappointing and you're angry. There is something you can do about it. Accept that he is this way. Love him. Support him in a positive way. Do not make him feel bad about his head shape. He is perfect just the way he is.
How old is your son? It's only been in the last few years that treatment by using a helmet has been accepted and yet this is controversial. It's only this generation that expects perfectly shaped heads. My generation and the one after accepted that shapes vary and that's Ok. The only time I see an uneven shape of head to be a problem is if it's so oddly shaped, kids make fun of it.
Relax. He's OK. You're not at fault. Really, no one is perfectly shaped. You son needs to feel that you're OK with this. If not, he will feel guilty because you feel guilty. Kids always believe things are their fault.