Honestly, as a guy, I'm not overly concerned about a girl's teeth being ever so slightly crooked, especially if the girl in question has a good personality and stuff. Like, if you asked me for a list of things important for me in a girl, her teeth would be very low on the list if they were even on there at all. Obviously I can't speak for other people, but I would say that someone who dismisses a person based on their teeth, irrespective of personality or anything else, probably isn't really worth the effort to begin with.