A dentist's ingenious hack for making a face mask fit better has been viewed 3 million times on TikTok

• A Canadian dentist has shared an ingenious hack to make a standard face mask fit better and work much more effectively.
• Dr. Olivia Cui, DMD, posted the trick in a TikTok video which has now been viewed 3.4 million times.
• All it takes is a fold and a couple of knots.
• The video has wowed people around the world, and Katie Couric and Kristen Bell have both shared it.

A dentist has shared an ingenious and simple hack to make a standard face mask fit better and work more effectively, and the video has been watched 3.4 million times on TikTok.

Canadian dentist Dr. Olivia Cui, DMD, showed how you can close the gap around the side of your mask in a matter of seconds.

All you have to do is fold the mask in half length-ways, tie a knot in each strap as close to the mask as possible, open the mask out, tuck the opening in underneath the ear loops, and you'll have a much more effective and better fitting mask.

Watch the video here:

Dr. Cui said the trick is particularly useful if you have a smaller face and find your mask gapes as a result.

"You will see that it's nice and fitted to my face all around," Dr. Cui said.

The hack has been gratefully received by people all across the world, many of whom have expressed their amazement in the comments.

Broadcaster Katie Couric and actor Kristen Bell both shared Dr. Cui's video on their Instagram profiles too.

"This is so helpful thank you for sharing!!" commented one person on TikTok.

Another added: "Me and my pea head thank you!!"