'Morning trolls!': Chrissy Teigen's brilliant response to mum-shamers on photo of son

Model, mother and Twitter legend Chrissy Teigen has proven once again that when it comes to taking down trolls, she's in a league of her own.

On Monday (local time) the 33-year-old posted a photo of her and six-month-old son Miles to Twitter. The adorable baby sported a white helmet, which his mother explained was to reshape his skull.

"Baby Miles getting fitted for a little helmet today for his adorable slightly misshapen head," she wrote.

"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."

Positional plagiocephaly, or 'flat head syndrome', is a relatively common condition in which babies (whose skulls are much softer than adults) develop a flattened spot on their head.

The number of cases has risen in recent years due to new baby safety guidelines, which recommend placing newborns on their backs to sleep rather than their sides.

Many parents were thrilled to see a celebrity normalising the condition, and posted photos of their own kids showing off their helmets.

However some weren't so happy about it, and questioned why Teigen would promote helmets for flat-headed children when their own kids with the condition turned out fine without them.

Teigen clapped back on Tuesday (local time) with a characteristically cheery acknowledgement of her critics.

"Good morning trolls!" she wrote. "Just a friendly reminder that you do not indeed know absolutely everything."

She said Miles had been seeing a physiotherapist for "muscle work" before she decided to have him fitted for a helmet.

"Just didn't want you guys to see pictures and wonder. Not promoting anything. Just sharing our story! Thank you back to your bridge now."

She also shared her delight at the hundreds of cute baby pictures her initial tweet had generated.