You can never spend too much money on your teeth. Just whatever it takes to make them stop hurting

There are many soft delicate parts of your body that are horribly vulnerable to injury: eyeballs, eardrums, your own particular brand of genitalia, and that's without getting on to the internal organs. But there's something special about horrible things happening to teeth.

Maybe it's because teeth are ambiguous things: they are both exterior and interior, they are hard objects attached to your soft wet gums, they seem separate from you and yet you can run your tongue over them so that the smallest ridge or crack feels like the surface of the moon. And they can hurt so much. Mine don't exactly hurt all the time: only when I put anything hot or cold in my mouth (including cold air) or bite on anything.

I don't think I'm a particular tooth-obsessive, but I think I can recall in detail everything horrible that has happened to a tooth in any book I've ever read. More than any of the horrors in Nineteen Eighty-Four, the rats and all that, I remember the moment when O'Brien makes Winston Smith contemplate the wreckage of his body: "He seized one of Winston's remaining front teeth between his powerful thumb and forefinger. A twinge of pain shot through Winston's jaw. O'Brien had wrenched the loose tooth out by the roots. He tossed it across the cell."

Terrible things happen to Nabokov's hero, Timofey Pnin, but nothing worse than when he has all his teeth extracted and suddenly realises, as he walks home with the anaesthetic wearing off, how fond he had been of them: "His tongue, a fat sleek seal, used to flop and slide so happily among the familiar rocks, checking the contours of a battered but still secure kingdom, plunging from cave to cove" - and so, wonderfully and horribly, on.

I'm eagerly awaiting Martin Amis's impending memoir, one-third of which, reputedly, concerns his notorious teeth. Amis created a scandal by supposedly spending too much money on them. But what could be too much where teeth are concerned? Whatever it takes just to stop them hurting.

I recently went to a new dentist. It didn't go well. The X-rays had strange shadows on them. The dentist called out some alarming technical things to the assistant and then she told me some even more alarming non-technical things to do with infections in the bone and loss of gum, and the result was that a couple of teeth that have been drilled and deep-filled and capped and crowned over the years now have to go in order to save the mouth as a whole. The first one has now gone and the experience was a return to the days when the dentist's day job was being a blacksmith.

After about five injections, there was no pain. The sound was bad enough. The tooth didn't want to come out. It thought it was going to be there for ever, so it fought back, and the noise it made while clinging to my jaw was like when you break a twig: not a dry twig, but a green one. There was lots of cracking and splitting, and about the only consolation was that it wasn't as bad as my number one horrible tooth scene; and, when I say horrible, I mean it's far worse than Laurence Olivier drilling Dustin Hoffman's tooth in Marathon Man - actually, I thought that if dentists are going to start drilling into the nerves of healthy teeth, then Dustin Hoffman's mouth is a good place to start.

I'm referring to a passage in Scott Turow's fine but - or do I mean fine and - deeply unpleasant thriller, Presumed Innocent, which has nothing to do with the main story, and I just have to assure you that it isn't some racist porno fantasy I hallucinated under the anaesthetic in the dentist's chair. Minors and those of delicate disposition look aside now.

An accountant called Marcy Lupino has been caught doing Mafia work and refuses to talk. So, instead of sending him to a Jonathan Aitken-style open prison, they send him to the state pen. A huge inmate (black, of course) wants Marcy to give him a blow job. When he refuses, "Drover takes Lupino's face and bangs it on the bunk rail until there is not a whole tooth left in Lupino's head". Lupino can't snitch on Drover, because then things will apparently get even worse (how?). Then, for the rest of his sentence, he has to give the blow jobs anyway, with Drover laughing about how "his big Johnson goes in there now, smooth as silk".

Gross, admittedly, but I sit in the dentist's chair thinking of Marcy Lupino. It makes me feel even worse.