"to the tooth" is way over used.
I don't know how many people I have known who are pasta experts because they can pronounce "al dente" and then tell you what it means in English. Everyone is in such a hurry to be gourmet correct that they CONTINUOUSLY undertook all pasta they serve.
There are three degrees of done-ness recognized by most chefs.
1- al dente, "too the tooth" barley done
I will guess that 80% of the fine restaurants I have dined cook pasta firm because they would lose nearly all their clientele in Los Angels or Naples if they served it "too the tooth". Some Italian interpretations of "Al dente" means you have to have teeth to eat it. Old people can't gum it. Somehow this craziness persists... you are getting the finest pasta dishes made with firm pasta, not pasta that you are required to have teeth to eat it.
Exasperated home chef
I'm happy for folk to call it "al dente" as I have a sense of what that means. The literal translation into English is just silly, meaningless and, in my experience, generally only used by smartarses.
All pasta experts can pronounce "al dente" but not all those who can pronounce "al dente" are pasta experts. Seriously, it just tastes better a little firm--the degree is highly personal--but once the mostaccioli's in your mouth, it's all yours. And I'd eye-roll anyone who says "to the tooth" with a straight face. Cheers.
Interesting point--many recipes for pasta fresca/ all'uova, like tagliatelle, suggest only a brief cooking, when the point to me of these wonderful fresh pastas is their soft silkiness. Need to make sure they're fully there. Dried tagliatelle or papardelle, usually made without egg, is another thing altogether.
I've always understood "al dente" to mean that the noodles are firm, not necessarily "crunchy" or something like that. There's no need to translate the expression litterally. If we did that we'd translate "a capella" as "to chapel."