What is the meaning of mew in genz slang?

The meaing of the word mew in genz slang means the following:

• A pseudoscientific method to reshape one's jawline by pressing the tongue to the roof of the mouth. Coined by British dentist John Mew and his son, Mike.
• Often discussed in online beauty and self-improvement forums.

Example

He started mewing daily to improve his jawline.