Understanding Flat Head Syndrome, Positional plagiocephaly.

By Philip Owen, D.O., B.Sc., (Hons) Paediatric Cranial Osteopath.

I specialise in paediatric cranial osteopathy and see a great many babies with flat head syndrome

Flat head syndrome has become much more common in the past 15 yrs or so. The reason for this is due to the very successful ‘back to sleep’ campaign that was started at that time. This campaign was introduced because it was noted in the mid- 1990’s that the incidence of cot death (sudden infant death, or SID) in parts of the far East, particularly Hong Kong, where the babies were being placed on their back to sleep was considerably less than here in the UK and in other areas of the world where the sleeping habits of babies was to be placed onto their back.

At that time, when babies were sleeping either face down or on their side, the number of cot-deaths a year in the UK with a birth population of over half a million was approx 3,000. Since the introduction of the ‘back to sleep’ campaign in which the advice given to parents is to place babies on their back to sleep, the number of baby deaths has reduced dramatically to less that 300!

The unexpected consequence, or side effect, of laying a baby for long periods on the back is that the weigh of the baby’s is resting on the soft part of the skull and a pressure indent may start to happen. When a pressure indent or flat-spot starts to take place on the skull  gravity will tend to rotate the head onto the flat spot, because it is stable, rather like a bucket having a flat bottom. The consequence of a baby starting with a flat-spot is that the very shape that develops makes the condition worse as the head is constantly being rotated back on the flattened area.

How many babies develop a flat head and why do some babies develop the condition whilst others don’t?

There is a variation on the exact figures of incidence, but according to the Great Ormond Street Children’s Hospital website it is thought that ‘around half of all babies under a year will develop ‘flat head syndrome’ (or positional plagiocephaly), but to varying degrees.’

There are several factors that may influence whether a baby develops flat head syndrome. If you look at a normal baby’s skull from the side you will notice the large bulge at the back. This is  ‘the Occipital area’. It is this bulge that makes a new born baby turn their head to one side or the other. When the baby is old enough to have full head control this bulge will push the chin onto the chest.

If a baby has a preferred side to rotate, or cannot rotate the head to a particular side (as in the case of torticollis) then all the weight of the baby’s skull is pushing down and will usually cause a flat head on that side. Hence the term ‘positional plagiocephaly’!

Another factor is how wrestless or calm is the baby. Wrestless babies who are constantly moving their head rarely develop ‘flat head syndrome’ whereas the calm baby who lies still for long periods of time and who rarely asks to be picked up frequently develops ‘flat spots or flat head syndrome’.

What are the different types of ‘flat head syndrome’?

By far the most common type of flat head syndrome comes from the weight of the baby’s head pressing on the soft skull bones, caused by lying a baby on a flat surface, be it a mattress, car seat or bouncy chair. (It should be mentioned that there is a much rarer condition called craniosynostosis in which there is premature fusion between the bones in a part of the baby’s skull which produces an abnormality in shape.)

The name given to a particular type of flat head syndrome caused by flat surfaces depends on where the flattening is most noticeable. If the flattened area is at the back of the skull the name given to this is ‘brachycephaly’.

If the flattened area is to one side at the back of the skull this is called plagiocephaly. Out of these two latter cases, caused by flat surfaces pressing against the soft baby’s skull the most common is plagiocephaly.

Cultural considerations. Why was it not as common 15 yrs ago?

Flat head syndrome 15 years ago was rarely seen in clinical paediatric practice. This was because

a) babies were not being placed on their back to sleep, as the link between cot-death and face down sleeping hadn’t been made and

b) our cultural habits have changed in recent years in as much that western culture tends to place babies in receptacles, such as push chairs, car-seats, bouncy chairs etc.

In other societies babies are carried more and for longer by the nursing mother. I currently run a mother and baby clinic in the orthodox Jewish quarter in both Manchester and London. Out of the hundreds, if not thousands, of babies seen in my clinic I not never seen a single case of flat head syndrome in that community, due to the fact that the culture is not to place babies on their back and to carry them for most of the day in the arms of the nursing mother.