Toothaches are awful, aren't they?
In fact, they are really high up there on the "pain scale" -- at least in my mind (and the minds of many patients that I see). I mean, think about it -- they are painful enough to drive someone to go see a professional who will drill (drill!) into said teeth (amongst other things). So yes, toothaches hurt.
I can't get its meaning or use.
As the Cambridge online dictionary puts it, "said" is:
Used before the name of a person or thing you have already mentioned
So what it means here is basically 'the teeth that are under discussion', 'the teeth in question', 'the teeth we've been talking about', 'the teeth I've already said something about'.
Those teeth, in this case, must surely be the ones which are affected by toothache.
