Positional plagiocephaly can develop at two different times in early life. The first time is at birth from positioning within the womb. The second occurrence may develop within the first 5 to 20 weeks of life and is as a result of infant's favouring one side head position. This second type of plagiocephaly can easily be prevented by using sleep positioners and alternating the baby's sleeping side.

There is research to suggest this condition seems to affect infant boys more than girls and has a higher incidence in low birth weight infants. The newborn infant's skull is composed of seven individual bones separated by sutures. This arrangement accommodates skull distortion during birth and allows future growth of the brain, the volume of which quadruples during the first two years of life.

The sutures will be open in the first few weeks of life but will close as months pass by. If the sutures close before the head growth is complete, the face and head of the child will start to experience changes. Similarly, if the head is subject to pressures that cause an abnormal position for the skull bones, the abnormality will be frozen into place after 8 to 9 months of life.

Plagiocephaly relates to the 'lanbdoidal suture' which is located on the back of the head. An infant affected by plagiocephaly has a head showing a persistent flat spot on the back or on the side of the head with one of the ears moving forward slightly.

Many parents turn to the help of a Cranial Osteopath to help manage and correct flat head syndrome. Treatments can include using a sleeping wedge to manage the alternate sleep positions each time baby is laid in their cot to sleep.