Over on Language Log, Mark Liberman’s latest posting about word rage focused on, among other things, impact used as a verb (in figurative senses), which arouses some people to extravagant displays of rage (if you’re interested in the facts of the matter, MWDEU has a substantial and balanced article on impact, as both noun and verb, and on the history of commentary on these words). “Impacted wisdom teeth” came up in comments, eliciting this aggressive response on 2 May from commenter JimG:
I haven’t got “wisdom teeth” that create problems, but if I did and a dentist spoke to me of an “impacted” wisdom tooth, I’d insist, on pain of a punch in his mouth, on an understandable explanation. As long as we’re exercising our peeves, this usage is one of my pets.
JimG’s antipathy to figurative uses of the verb impact has caused him to object to all occurrences of the verb, even in this long-standing and absolutely unremarkable use of impacted as a technical term in dentistry (to refer to a tooth that is trapped inside the jaw and so is unable to erupt properly). Mark Liberman noted in response that OED2 has dental uses from 1876. He didn’t note that there is no alternative term; you can hardly expect dentists to explain the condition in detail (roughly as I have done above) when there is a handy single word available (though of course dentists might explain what impacted means the first time they use it to a patient — though I’d think that most adults would already be familiar with the dental use).
Mark also didn’t comment on the fact that the dental use of impacted is merely a specialization of a much older use of the adjectival past participle: ‘closely in, firmly fixed’, in OED2 from 1683. Or that this past participle is a form of the transitive verb impact ‘to press closely into or in something; to fix firmly; to pack in’, in OED2 from 1601. Figurative uses of the verb (which set off some people’s peevemeter) are much later extensions, but the dental use continues the “original”, literal, sense.
The story is even more delicious. As MWDEU explains, the verb impact ‘pack in’ was not a verbing of some noun impact, and in fact this verb appeared well before a noun impact did (in its literal sense ‘collision’, in OED2 from 1781 on). MWDEU argues that later figurative uses of the verb weren’t verbings either, and developed in tandem with later figurative uses of the noun.
So JimG can willfully fail to understand “impacted wisdom tooth”, if he wishes, though there’s no rational basis for this action or historical justification for his antipathy to impacted here. And he’s welcome to request an explanation from a dentist who uses the expression, but punching the dentist in the face would be an absurd and unwise over-reaction.
