As I understand it, the japanese consider fang teeth and the like as being 'cute' and many girls even once they are bringing in enough money for serious dental work, choice not too.
I've lived in Japan a long time. "Fang teeth," which are protruding canine teeth, are sometimes seen as a "charm point." Buck teeth (出っ歯), like Sakura's, are definitely not considered cute. Standards for teeth have changed a lot since Seiko Matsuda ("Seiko-chan") was charming the nation with her fang teeth back in the 1980s...
...but even Seiko-chan eventually had her teeth fixed and now boasts a perfect set:
A current idol who had major fang teeth, Momoiro Clovers' Kanako Momota, has been fixing hers over the past couple of years, as you can see here:
http://shinbishika-guide.com/momotakanako/
The orthodontist who made this page says she almost certainly has behind-the-teeth braces that are pulling her canines in.
Then:
Now:
(If you're wondering what the hell is going on in the second photo, she's showing off her dimple power by holding a one-yen coin in her dimple.)