During early infancy, a baby's skull is still soft enough to be moulded by these external pressures, which can lead to areas of the skull becoming misshapen and result in brachycephaly.

What causes brachycephaly head shape?

Brachycephaly and plagiocephaly are commonly caused by the baby sleeping on their back every night. The back or one side of the baby's head (if their head naturally rolls to the side) is squashed against a firm mattress for a long time, which eventually forces the soft bone of the skull to flatten.

How is brachycephaly caused?

Brachycephaly is caused by symmetrical flattening of the occipital bone area at the back, lower part of the skull. These infants have little or no rounding on the back of the head and a disproportionately wide head when viewed from the front.