It is for most pokémon that have teeth, but with a mawile’s false jaws, it’s actually far easier to take care of. The fact of the matter is that a mawile’s horns are normally lose their teeth every so often because they’re used to bite deep into a victim and hold, even when the victim struggles. Losing teeth is simply often inevitable in these situations. Thus, a mawile’s horns can regrow teeth rather quickly.
In other words, don’t worry! Your mawile will be fine. As for the tooth, some trainers like to collect them to make jewelry or as keepsakes, but otherwise, it would be fine to throw it away.
The Pokédex According to Bill 