I know what you're talking about, Drake did that for a while. The thing is that Newfies were bred to use their mouths as a pulling tool. So it is in their nature to use their mouths. But they shouldn't do it every time someone reaches out to them, which is a puppy issue. The only thing I would suggest would be to pet him a lot so they are used to hands being by their head. Don't deny playing tug-of-war or even rough housing, they need that kind of stuff, they really, really do. You're just going to have to be patient and vigilant in correcting him. Remember, you have an incredibly intelligent dog on your hands, he will learn. You are the boss, they have to learn your rules. Give it time, but also realize that Newfs are going to irk some people they approach because of the drool, especially neat freaks. That is something that never goes away, their mouths are one of the biggest issues to deal with. And then there's the hair.....