[quote FluffyPJs]@SchadenfreudePersonified off topic tooth related note - I had a tooth removed a few years ago that broke into bits during the extraction and the dentist was unable to get the last root. She assured me it would work it's way out by itself. It was a top molar, and eventually it worked its way into my jaw joint, causing unbelievable pain and swelling. I had to have oral surgery to remove the root. On the plus side I lost a stone because I couldn't chew food for weeks! If your root hasn't worked it's way out soon, I would recommend asking them to X-ray and check where it is, as you REALLY don't want it to play hide and seek in your jaw joint (is there a proper word for that?) [/quote]
There is Fluffy!
It is the tempero-mandibular joint" - and your post has struck terror int my heart! 
The dentist gave me a timeline of FIVE YEATS for it to work its way through, but I will follow your advice and if I have ANY concerns / pain/ jaw discomfort whatsoever, I'll get it checked straight away. TBH, it does seem more likely to me that the tooth would work its way UP, the way the pointy bit of the root is, rather than DOWN, the way the blunt end. At the moment it isn't massively painful. I am aware of it, but I think that that's because inside my mouth must be very bruised. My upper cheek on that side looks as though I am trying to smuggle an apple through customs.
I grilled the dentist about what was likely to happen, and I particularly asked about blood poisoning because about 10 years ago a friend of mine had a tooth break off during an extraction and she ended up in hospital with blood poisoning - but to be fair, she had an access on her tooth as well. She had been given antibiotics by the GP to clear it, but it wasn't fully banished and the dentist told her it would be fine (it wasn't!)
She is also one of these poor souls that nothing ever went right for, medically speaking. She had an op to tighten up some muscles that would stop her weeing herself . She was a small woman and had had two enormous (for her size) babies - both over 10 lbs - and it had left her very incontinent. She had a stroke on the operating table (she was 44) and was very badly effected. Fortunately she made a good.but not complete recovery, but had to give up her job (as a midwife), and act as reception nurse in a family planning clinic instead). She had LOVED her job, too. 18 years later she still isn't quite what she was.
Her whole life is a catalogue of similar medical disasters, poor girl. (Plus her husband and sons were the most selfish, useless articles on God's earth, but that's another story.)
In retrospect I wish I'd just let him continue to hack away, but it was getting increasingly painful, and I have what almost amounts to a dental phobia to start off with. I really should have asked for another numbing injection, because i'd been in so long the effects were wearing off. Normally I'm not backward in coming forward regarding these things, so I must have been in quite a state.
"I knew I would get a chance to use that snippet of knowledge one day, but I expected it to be in a pub quiz. Now I just need someone to ask me what an English landrace is and I will be in smart*rse heaven! 