Why Chrissy Teigen and John Legend's son Miles is wearing a helmet.

Chrissy Teigen has been commended for sharing a picture of her son Miles wearing a head shaping helmet.

On Twitter Teigen wrote her “baby bug” was fitted for a helmet to fix his “adorable slightly misshapen head”.

“If you see pictures, don’t feel bad for him because he’s just fixing his flat and honestly he’s probably gonna be even cuter with it somehow.”

And she was right.

GUYS pic.twitter.com/V5dzkmVCGu

— christine teigen (@chrissyteigen) December 3, 2018

The helmets are used to treat plagiocephaly – otherwise known as flat head syndrome.

Associate Professor Alexandra Martiniuk wrote that flat head syndrome “develops in babies because of external pressures on the soft, malleable baby skull” in an article for The Conversation.

She said it is more common now that SIDS safety guidelines recommend babies sleep on their backs.

According to the Royal Children’s Hospital Melbourne, most babies do not need any treatment as it usually improves naturally as they grow and can move their heads on their own.

The hospital states than one in 10 are treated with helmet therapy, which involves wearing a lightweight fitted helmet to reshape the skull.

Parents can prevent plagiocephaly by alternating their babies head position while they sleep (though they must always be placed on their back), lying them on their front when they are awake and during play time and varying their holding and carrying positions.

Twitter users praised Teigen for speaking about Miles’ helmet use and shared their own (adorable) photos of their babies in helmets.

This is social media at it’s best! Informing and supporting – you all are amazing parents with such precious babies! It warms my heart to read and see these posts and pictures ❤️

— NancyE (@NancyE54451193) December 4, 2018

Chrissy, really cool of you to share. All of us parents have these moments with our kids and it just makes it easier to talk about them when you see you are not alone. You are the ???? of Twitter !

— matt derella (@Derella) December 4, 2018

My son had a helmet and it made him even more adorable if that’s possible. My wife hand painted it! pic.twitter.com/Hu1y7NkzVy

— Scott Osborn (@asosborn) December 4, 2018

My nephew! He’s the happiest baby in the world, helmet or no ????

(real talk his head gets a li’l stinky but luckily he loves baths) pic.twitter.com/O4VosIPpsg

— Arpita (@ArpiAppa) December 4, 2018

Teigen and husband John Legend welcomed Miles, their second child after daughter Luna, in May.