Friday 30 March 2018

Dental affairs

Getting on for a hundred years ago, my father was a bright young dentist who took an interest in the history and philosophy of teeth. By the time I was old enough to remember, this had moved on to his taking an interest in the work of a colleague on the growth of teeth and jaws, with the particular point of interest that I remember being how to superimpose one photograph of a mouth on top of another, taken some time previously. Where was the fixed point? A version of which issue which lives on to vex brain scanner scientists today.

So it seemed entirely proper to attend a talk at the Royal Institution given by Peter Ungar on 'Evolution's bite: A story of teeth, diet and human origins'. The Ungar of the University of Arkansas, who runs the laboratory noticed at reference 1.

But the evening started with South Western Railway, the nearly new franchisee for our part of south London, when at Wimbledon I was able to spot rolling stock in the old red livery of Southwest Trains, the new red livery of South Western Railway and a brand new stripy blue livery of South Western Railway. Possibly used on rather grander trains than those which run through Epsom.

Out at Green Park and into Albemarle Street to find one of the clothes shops there was having an event. Lots of pretty people, both male and female, sipping champagne. One looking very pregnant and wearing a very handsome brown dress, providing decent cover but otherwise entirely suitable for cocktail or evening wear. Lots of stocky looking security guards outside. Lots of rickshaws to carry the guests away afterwards.

Quick fix in the Goat and then on to the Institution. Which, for the first time in my experience, was barely half full. Usually more or less full, if one does not count the seats in the gods.

Ungar started by observing that teeth were useful in the study of evolution because they tell us something about the life of their one-time owners - with mammals being the owners of interest here - and because they survived. There are lots of teeth out there and the shape of the various teeth and the way they are fitted into jaws tells us something about what their owners were intended to eat. Grass, flesh, fruit or nuts? While the way that they have been worn tells us something about what their owners actually did eat. But one had to have a care as sometimes the habits of opportunistic mammals outstripped their equipment. And plenty of mammals had a seasonal diet, a diet which was hard to sort out from a small sample of teeth fossil frozen at some particular point in time.

One of his specialities was the application of the tools of geographical information systems to the small world of teeth. An interesting example of how one discipline can inform another. It's just a matter of bringing the right people together and getting them motivated...

Monkeys and apes were interesting because there are lots of different sorts, with lots of different life styles and diets, spread over large parts of the world. Lots of teeth.

Many people in the western world had small jaws, particularly small lower jaws, which meant that wisdom teeth got impacted and lower front teeth got muddled up - both of which complaints I recognise. It seems that while the size of teeth is pretty much determined by genes, the size of jaws is not and heavy use when young does stimulate their growth. So Ungar was able to point to a particular tribe of hunter gatherers who, for this reason, very rarely suffered from either complaint. But nor were they able to pronounce the sound for 'F', which is, it seems, much easier with the western jaw.

Considerations of this sort were part of the reason why people selling diet fads were able to do so well out of the Paleo Diet, big in the US and illustrated above. A diet which takes you back to the good old days when we chewed mammoth flesh in our caves and had perfect teeth. And died at 20 or so, if we were lucky enough to survive that long. But the diet people probably leave out that bit of the story. I associated to another story about the back teeth of mummified Egyptians, worn down to their gums by all the grit which found its way into their flour. Perhaps they would have done better to stick to hippo steak.

An interesting, but not particularly well organised talk - which was perhaps why there were good questions, provoking good answers. The better quality talks don't leave the chinks you need to be able to stir things up a bit.

Rounded off the proceedings with a second visit to the Goat. Where we learned that there had been a Goat tavern since 1697. Not clear whether the tavern has moved house in the interval, but it is a London public house of the old style, plenty of brown wood and cut glass, of a sort which is becoming rare outside the West End - with the Sutton Arms near the Barbican, noticed at reference 4, being the exception which proves the rule.

Up the stairs at Vauxhall to be overtaken by no less than three young people. One thin gent. bounding up the stairs two at a time. Two short, young females who just about managed to pass me, but were definitely puffing by the time they reached the top. I can't remember the last time that anyone other than me was climbing up the hard way.

Reference 1: https://ungarlab.uark.edu/.

Reference 2: Evolution's bite: A story of teeth, diet and human origins - Peter Ungar - 2017. The talk was, at least in part, a book promotion and Ungar was up for signing. Very tempted, but decided that my pile of unread books was quite high enough already.

Reference 3: https://thepaleodiet.com/. Only in the US of A - at least so far. Maybe when the Tories have finished smashing up the health service, we will see more of this sort of thing over here.

Reference 4: http://psmv3.blogspot.co.uk/2016/05/citadine.html.

No comments:

Post a Comment