Brachycephaly: The infant’s head is flat on the back part of the skull. This occurs if your baby spends a lot of time on their back.
Plagiocephaly: The infant’s head is flat on one side. This occurs if the baby tends to keep their neck turned to one side.

  

A baby is most at risk to develop a flat head in the first four months of life. A newborn baby’s skull bones are soft and thin to allow for easier passage through the birth canal.  This makes the skull of a young baby more moldable.  In addition to this, a younger baby is not yet strong enough to roll or change their position on their own. 

If your baby prefers to look in one direction or spends most of the time on his or her back, this can cause it to become flat.

In the 1990’s the American Academy of Pediatrics and the Canadian Pediatric Society launched the “The Back to Sleep” campaign to reduce the incidence of Sudden Infant Death Syndrome (SIDS).  While the incidence of SIDS has decreased significantly, babies are spending more time on their backs and are more likely to develop flathead.