The other type of plagiocephaly is congenital plagiocephaly. It is a skull defect known as craniosynostosis. In congenital plagiocephaly the bones of the skull fuse prematurely, affecting the shape of the baby's head. The treatment for this congenital condition is surgery to allow the skull bones to grow naturally before fusing. 
This health information is about positional plagiocephaly.