Clipping wolf teeth on piglets has nothing to do with tusks on adults.
We don't clip wolf teeth nor do we cut tusks on boars and sows. FYI, sows have tusks too. I save the tusks from the boars, sows and even finishes.
Tusks do get sharp because they rub against the top teeth and they grow continuously.
The biggest tusks I have are 11.5" long. That is rare as normally they break off or wear down at smaller sizes.
See photos here:
http://sugarmtnfarm.com/bigun-tusks/