In an old Dungeon there is a scenario where a dentist is using teeth from a lychantrope to repair patient's teeth, with dire results.
Oh yeah, I vaguely remember that one! Didn't it have a seawolf aquatic lycanthope involved? I might be getting two modules mised up.
Either way there's a lot of cool plots that can come out of stuff like this.
When it comes to wierd setting concepts and 'rules' about monsters and magic, I think people sometimes use concepts like this in the worst ways, as a fixation on continuity, or a way to screw over their players. OTOH, all that lore can be a great way to come up with coll, wierd plotlines.
Even if the PCs would never think of turning everyone into werewolves, it doesn't mean somebody else might not think of the idea. These kinds of crazy desperate mad schemes can make an interesting counterpoint to a scenario in wich the end of the wolrd might be looming- or just the end of the local point of light.
They could even have a fair bit of merit. I just read a module that ran in Dungeon recently- it about ghouls taking over a town. Imagine if, in your normal undead plague scenario, a town gets word that an undead horde is heading their way- and rather than panicking or trying to mount a futule defence, decide that they would commit mass suicide by immolation, rather than allowing themselves to be turned into undead, and sent against their neighbors in a ravenous horde.
There could actually be advantages in such a plan, if things were desperate enough, and the alternative was a city full of people being added to the swelling ranks of an undead horde. And of course it wouldn't have to happen- the PCs could come on the scene, and convince the townsfolk that they can save them. Then again, even in a straight laced, heroic party, it could prompt some interesting debate.
This might all seem pretty bleak, but it's oddly heroic, could emphasise the stakes, and would cast the villagers in something other than the 'utterly useless help seekers' they normally appear as.
