According to a recent study by Calgary's Mount Royal University published in the journal , nearly half of 440 babies studied between seven and 12 weeks of age had the condition. Of the babies found to exhibit flat-head syndrome, the study found that 78 per cent had a mild form, while 19 per cent of cases were classified as moderate, and the remaining 3 per cent were severe. More than three in five babies had plagiocephaly on the right side of the head.

In Hong Kong, figures are not readily available, but according to Dr Simon Wong, a specialist in paediatrics, flat-head syndrome is very common. "I am not aware of any local studies on this subject but I suspect the incidence would be similar to those of the Western world," he says.

The condition arises because a baby's skull is still soft enough to be moulded and to change shape if there is constant pressure on one area of their head, according to Britain's National Health Service. The skull is made of plates of bone, which only start to strengthen and fuse together as the child grows older.

Babies are also being placed in reclining carriers, car seats, and swings now more than ever, making them even more vulnerable to developing the condition in the first few months of life. Plagiocephaly is even more common with multiple or premature births as premature infants with prolonged hospital stays are at risk.

The abnormal head shape itself will not result in any developmental abnormalities if the skull sutures are not fused, as the brain still has sufficient room for growth.

Dr Hannah Tsang Yee-Hoi, a specialist in paediatrics at International Doctors Limited, Hong Kong, says treatment for positional plagiocephaly is primarily cosmetic. Studies have shown that a baby's head shape usually improves spontaneously after the first six months, if there is no other underlying condition which is causing the positional plagiocephaly.

There is improved head control between four to six months of age, which results in better movement and a lower tendency to remain in a fixed position. Wong says the vast majority of cases do not need aggressive treatment. The skull's shape gradually improves with simple measures, six to nine months later.

"Babies with isolated positional plagiocephaly have excellent long-term outcome," he says. "They do not have increased risk of hearing, visual, cognitive impairment. Their skull shape may not be as round as children with 'normal' heads but the appearance will improve with time. None of my patients with isolated positional plagiocephaly have negative long-term outcome and none required surgery."

But if there is an underlying cause for the fixed head position, treatment of that cause is essential. For example, improved head shape will be seen after treatment and correction for congenital torticollis (an abnormal, asymmetrical head or neck position), because the child will be able to move his or her head more freely.

Tsang adds that it's important to note that there are syndromal disorders that are linked with both flat head and developmental delay.

The window of opportunity to correct flat head syndrome is usually zero to six months, after which treatment is less effective. By the end of the first year, a baby's skull has hardened and most therapies have little effect after this time. Hence, prevention is key.

The most common form of treatment is counter positioning. Parents should change the baby's head positioning after each feeding, alternating sides so that one does not become favoured. Alternating the arm in which the baby is being held while feeding, and the side from which he or she is approached during diaper changes also helps.

As babies gets older and strong enough to move on their own, parents can try attracting them to alternate sides, perhaps by putting a favourite toy on their less favoured side. Another tactic is turning babies around in the crib so that they naturally turn towards their caregivers and the activity in the room.

Tummy time - supervised time with a baby lying on its belly - can also help prevent flat-head syndrome.

There's also the Tortle beanie invented by paediatrician and neonatologist Dr Jane Scott. She suggests that getting babies to wear the beanie for six to eight hours a day, along with counter positioning techniques, can help prevent and treat the early stages of flat-head syndrome.

Dr Faisal Nahdi, consultant paediatrician, Rainbow Group of Hospitals, Hyderabad, India, says most of the children she has seen have responded well to a "conservative approach".

If a baby is beyond the window to try counter positional therapy, there is a high rate of success with treatment that is a combination of helmet and physical therapy. Such cases are referred to a paediatric neurologist for further management, which includes corrective helmets and caps.

Sometimes when the uneven head shape is more severe or where counter positioning does not work, a cranial remodelling helmet may help. An orthotist makes a cast of the baby's head to create the helmet.

In the print article published Oct 9, 2013, syndromal disorders were described as anxiety and depression. This is incorrect. Examples of syndromal disorders are Apert syndrome and Down syndrome. These are just two examples of syndromes that need to be ruled out by the absence of other clinical features before a child can be diagnosed as having positional plagiocephaly.