Via Gamesradar.com:
Scars run deep in a galaxy far, far away. Unless you’re Kylo Ren that is. Star Wars: The Last Jedi director Rian Johnson wasn’t a fan of the scars Kylo Ren was given in his climactic tussle with Finn and Rey in Star Wars: The Force Awakens so he changed them to make them look cooler. Obviously.

Johnson took to Twitter to justify his slight adjustment to the “goofy” scars and, honestly, he’s completely right. Ren now looks more Big Boss (i.e hella cool) instead of a patched-up Frankenstein’s Sith monster.

The Star Wars: The Last Jedi trailer shows Kylo Ren with a giant scar over his right eye – which you can see below – (h/t ComicBook.com) and gets rid of the snaking mark that dominates Ren’s face at the end of The Force Awakens.