A device and method for preventing and correcting abnormal shaping of an infant's cranium by applying external forces over time with the growth of an infant to achieve normal shaping of the infant's head. The device is a cranial orthosis having a depression with a contact surface in the shape of at least a portion of a normal infantile cranium. The orthosis further provides lateral support surfaces creating points of contact to restrict rotation of the infant's cranium and provide additional external forces for normal shaping of the infant's cranium. Because the present invention is non-conforming to the shape of an abnormal skull, the exerted forces cause accelerated expansion of the skull in less prominent areas coincident with brain and skull growth.