My mother's wisdom teeth grew roots around her jawbone so that she couldn't open her mouth enough to eat. In a low-tech environment, she'd have died before reproducing. Of course, in the "state of nature," she probably would have had children in her mid-teens (which was before the teeth problem) rather than late 20s.
So, can I conclude that you’re saying that your example is “inconclusive”? :)
Seriously, though, the tendency for the WT to cause problems IS genetic, and if it was a survival issue, this tendency would have “evolved out” of our genome before now.
The existance of a tendency towards homosexuality is really a strong counter-example for evolution, don’t you think?