What Happens If the Muscles of the Cheek Were Cut from the Corner or the Mouth to the Jaw? (photo)

My friend wants to get a very serious body modification done called a Glasgow Smile. The cheek would be cut from the corner of the mouth to the connecting jaw, literally extending their smile and left to heal "open" not letting the cheek heal back together. What would the effects be to facial expression? What risks would be involved? I have enclosed a picture of a fake Glasgow Smile to show what they wish to get. When it heals they want to get piercings to then hold the cheeks together.