Glasgow smile

A Glasgow smile (also known as a Glasgow grin, Anna grin, Chelsea grin or Chelsea smile) is a nickname for the result of cutting a victim's face from the edges of the mouth to the ears. The cut – and the scars it leaves – form an extension of what resembles a smile. Sometimes further to hurt or even kill the victim, he or she would then be stabbed or kicked, most notably in the stomach (or in case of kicking, the groin), so that the face would be ripped apart when the victim screamed. The practice originated in the Scottish city of Glasgow, which gave it its name. It also became popular in Chelsea, London (where it is known as a "Chelsea grin") and other areas of Britain, for gangs hoping to leave a message to rival gang members. If cut deep enough, the victim may bleed to death.

Mutilation of this kind is commonly inflicted with a utility knife, glass or bottle.

In Batman The Dark Knight, the Joker (as portrayed by Heath Ledger) has a Glasgow Smile due to two possible things that may have happened; his father attacking him, or he self-mutilating to help out his wife after she'd been through the same and couldn't handle not being able to have corrective surgery.

Historic occurrences

 * Elizabeth Short, more famously known as the Black Dahlia was believed to be given a Glasgow smile during her murder, as when police recovered her body, her mouth was slit from side to side towards her ears.
 * Albert Fish, a child rapist/murderer in New York during the late 1920s to early 1930s, gave one of his victims, Billy Gaffney, a Glasgow smile. This was part of the brutal torture, murder and mutilation of the 4 year old victim. In a letter given to Billy's parents, Fish described whipping the boy until he bled and proceeded to explain that he "cut off his ears – nose – slit his mouth from ear to ear. Gouged out his eyes. He was dead then."
 * William Joyce, aka 'Lord Haw-Haw,' a British Fascist who made propaganda broadcasts from Germany during World War II (and was executed for treason after the war), received a Glasgow smile while stewarding a Conservative Party meeting.
 * Tommy Flanagan, a Scottish actor who has had roles in Braveheart, Gladiator, Alien vs. Predator, "All About the Benjamins", Sin City and is currently a regular cast member on Sons of Anarchy, has distinctive scars, similar in shape to a Glasgow smile, given to him during a mugging that nearly left him dead.