False Flush teeth...

Severn Trent Water has posted pictures of nine sets of false teeth on their website in an attempt to reunite them with their previous owners. Recovered from a sewage processing site in Shrewsbury, it seems unlikely that many will apply to reclaim them - but Severn Trent is hoping that some people out there will email in and 'nominate their gnashers'.

Unusual suspects: Erroneously discarded dentures (Photo courtesy of Severn Trent Water)

This unusual festive campaign is part of a drive to stop and make people think about what they discard down sinks and toilets. False teeth are just one of the inappropriate objects found in the sewage system which run the risk of blocking drains and causing flooding. Severn Trent spend over £10 million every year cleaning sewers and clearing blockages - but by showcasing these dentures, they're hoping to raise awareness of the issue - finally getting to the root of the problem!

Art is tooth...

The creators of an art-science sculpture, designed to stimulate debate about stem cell research, have been putting out a call for milk tooth donations from school children across the UK.

The two metre long clear crystal resin sculpture is to be encrusted with the milk teeth of thousands of children, who are being persuaded to part with them on the understanding that a 'tooth token' or letter of explanation will suffice for the traditional financial reimbursement from a visiting tooth fairy.

The crystal resin 'palace' prior to tooth encrustation (Photo courtesy of the BBC)

The project, called PALACES, is a collaboration between artist Gina Czarnecki and Professor Sara Rankin (Imperial College London). It hopes to create a wider understanding about how stem cells within dental pulp (the squishy bit inside your tooth) and other 'discarded body parts' such as umbilical cords or fat from liposuction could be ethically used for regenerative and therapeutic clinical purposes.

A close-up of the baby teeth, the first few of thousands! (Photo courtesy of the BBC)

If you know anyone - probably around the age of seven - who would like to be involved and send in their milk teeth, go to this page here to download a form to do so. The sculpture will go on display at science events and exhibitions throughout 2012.


 

Love, love me tooth... an update!

John Lennon's decayed tooth fetched the grand sum of £19,000 at auction last week. Unconfirmed reports have suggested that the buyer was a dentist from Canada - which I hope this means it was bought as an investment to lure more people into his practice. The idea that it was bought for not much less than the average graduate wage in the UK, for pleasure, is a bit strange.

But, by using the power of maths, we now know how much John Lennon's mouth was worth!

£608,000*

Impressive, I think you'll agree...





* That's 32 (the number of teeth in most adult human mouths) multiplied by £19,000, fact fans!

Love, love me tooth...

A tooth belonging to former Beatle John Lennon is up for auction at the Omega auction rooms in Stockport in November.  Lot no. 233 is a tooth with a sworn affidavit of authenticity by house-keeper Dot Jarlett, who was given it as a souvenir by Lennon.

A Beatle's tooth. Photo from Omegaauctions.co.uk.

Official documentation doesn't appear to give any information about this tooth though, so I thought I would.  It seems to be a third molar - a wisdom tooth - probably an upper one.  It's hard to tell if it's from the right or left side of the mouth though.  There's also a noticeable cavity, which is probably the reason the tooth was removed back in the 1960s.

However, the cavity is not as substantial as it first appears.  The difference in colour of the tooth enamel from the top of the tooth (off white/yellowish) and the lower part of the 'cavity' (white) is quite substantial.  I'd guess that a small amount of enamel broke off at some point in the last few years.  Perhaps that might surface at auction one day too.

The guide price for this item is an astonishing £10,000 to £20,000.  Whilst it might be unique, it does seem like a lot to pay for something that probably caused its owner a great deal of pain and was given away at the first opportunity.  It probably didn't even inspire him to write songs - not a single Beatles song contains the word 'tooth'!

When teeth go wrong!

Sometimes, whilst looking at thousands of teeth, you notice something that isn't quite right. This is one of those things:

A tooth with two crowns and one root... weird, eh?
Looking at the top front teeth (the incisors) in the upper jaw
of a c. 4-6 year old individual. Medieval.

Adult humans generally develop the same number of teeth.  Most of us have (or originally had, prior to dental intervention) four incisors, two canines, four premolars and six molar teeth in our upper and lower jaws.  It's fairly common however, for some teeth to never form (agenesis). For example, up to a third of the population is congenitally missing at least one of their wisdom teeth  - the final molar teeth to erupt.

It's much rarer to see instances of too many teeth (hyperdontia).  And it is rarer still to see teeth like the one in the picture above.  All of the baby teeth form in the womb, ready to erupt in the infant a few months after birth. This starts in the sixth week of embryonic development, when enamel-forming cells imbed themselves into the site of future primary teeth. At this point, not more than eight weeks into development, a genetic mutation must have occurred to produce such a tooth. Perhaps too many tooth buds initiated, perhaps one divided into two.

Of course, in all likelihood this unusual looking tooth wasn't even noticed, by the child or his family.  Had the child lived, it would have been replaced by the permanent teeth coming through about six years later and we would have never seen it.

Tweeth

Having been glued to the microblogging site Twitter for the last 24 hours watching the 'rioting' events take place in London, I've been surprised by how people are using such a service. There are people both condemning and inflaming the situation, personal messages about what's going on and public words of warning, of places to avoid and so on.

What this has to do with teeth of course, is very minimal. But it reminded me of a recent article in the Journal of Dental Research about using social media and microblogging sites like Twitter to carry out 'public health surveillance'.  Researchers analysed 772 random and unique (but tooth related) updates from Twitter users to see how such a site could was being used to disseminate information about dental pain.  Since tweets are limited to 140 characters in length, users update more frequently in real-time, indicating that it could be a useful rolling data source.

The collected tweets were placed into various categories - statements of general pain and discomfort, or a report of action taken in response to that discomfort, for example.  Unsurprisingly for a blogging website, general statements of pain were the most frequently observed updates (83%).  Of those who tweeted about taking action (22%), most employed or desired the services of a dentist or some sort of medication.  Interestingly, 14% of the updates were seeking advice for relief of their dental pain.

Word cloud created from the tweeted information. The larger the word, the more frequently it appears. From Heaivilin et al: 2011.

Although such a method of data collection has its limitations, it is important to acknowledge that user generated content of this nature is growing in popularity. If people are sharing such information online and asking for help and advice about dental pain (and one assumes other conditions too) it might be a sign that medical professionals should consider interacting more with the medium.  Heaivilin et al acknowledge that as dental professionals, they might "need to act quickly to ensure that [they] are part of the conversation."

As an aside, it has also made me realise that ordinary, every day updates on sites like Twitter and Facebook can be easily used to harvest information like that in the article. I wonder who else is listening to these 'conversations', how they are analysing them and what other articles are being written about them, as we tweet...

References:
N. Heaivilin, B. Gerbert, J. E. Page, J. L. Gibbs. Public Health Surveillance of Dental Pain via Twitter. Journal of Dental Research, 2011; DOI: 10.1177/0022034511415273

Happy teeth

Over time teeth tend to wear down. This happens particularly in populations who eat a lot of hard, unprocessed or gritty food.  The white of the enamel gives way in little patches to the material beneath it, dentine, which is softer and yellowish in colour. Osteologists can use dental wear to determine the possible age of an individual or the kind of diet they might have had.

However, as I've been looking at teeth, I've discovered something else. At a certain point, the little islands of dentine coalesce and start to look like faces. I shall demonstrate...

A cheerful 2nd molar...

Sure, this isn't a finding that will make it into the text of my thesis (unless I'm really, really struggling for word count) but it's something that everyone seems to appreciate.  How can you not enjoy looking at teeth all day when they look like this?

Another cheerful molar...

False teeth?

In the 18th century it was common practise to extract an unhealthy tooth from an individual and replace it with the tooth of a willing and hopefully well paid volunteer.  As unlikely as it sounds, this worked, at least occasionally.  Even now, teeth that have been displaced or knocked out can be eased back into the socket of the jaw (of their original owner, of course) and sometimes heal very well.

You'll be pleased to know however that you need no longer worry (if you ever did) about having a friends tooth forced into your dental arcade. Recent work at the Tokyo University of Science in Japan has shown that a bioengineered mouse molar tooth, grown from embryonic cells and subsequently transplanted into a jaw can successfully 'take root' and restore bone volume in the jaw.  This is the first time a complete organ has been created and transplanted in such a manner.

The transplanted tooth (bottom row) well healed and looking 
good after 45 days.  Note the lack of tooth and surrounding bone tissue in the 
control specimen,which cannot repair or replace itself.
(Image Takashi Tsuji, Tokyo University of Science)

The tooth was grown in a lining around the kidney of an adult mouse, a method which limits its application to humans at this point. However, the signs are good that one day losing teeth and the surrounding supporting tissues may not be such a bad thing - you may be able to get your very own teeth to be grown to order, using your own cells.

It's probably wise not to throw away your dentures just yet however - it's probably going to take a while to perfect the technique for application in humans.

References:
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0021531
http://www.newscientist.com/article/dn20682-artificial-tooth-transplanted-into-mouse.html

Decapitations and modified Viking teeth...

In 2009, archaeologists in Weymouth, way down on the south coast of England, found a mass grave containing 54 bodies and 51 skulls. Radiocarbon dating has placed the assemblage in the 10th or early 11th century - and isotopic evidence gleaned from testing the tooth enamel of the individuals within the burial pit has revealed a cold climate origin for them all. One of them may have even grown up somewhere in the Arctic circle.  Such a group is likely then, to be a Viking raiding party - a party that was somewhat curtailed by being rounded up, stripped, hacked to death, decapitated and thrown into a large pit.  That'll teach them to go raping and pillaging, I suppose.

Heads, not attached to the people they originally were attached to...

Of particular interest though, is the teeth of one of these young Viking warriors. There are a series of distinct horizontal lines on the front teeth which may indicate deliberate modification of the teeth. Teeth can frequently become notched and altered by repetitive movement (holding twine between your teeth, or smoking a pipe for example) but this usually affects the working surfaces of the teeth, or the areas between them, not the outward face of the tooth. These lines seem to have been filed into the teeth for some reason.

Two front teeth: All I wanted for Christmas

Deliberate tooth modification is not unknown in human cultures around the world, but it is fairly unusual in Europe. Groups from Africa and Southeast Asia are well known for intentionally removing teeth, chipping and filing them or insetting them with other materials such as brass or shell, blackening them with natural dyes or incising them. Such acts may be undertaken to show group affiliation, identity, or perhaps personal achievement within the tribe or nation.  There is no reason to expect the Vikings were any different in their reasons for practising this kind of modification.  It is even possible they picked up the idea from interactions with native north Americans on their legendary travels across the globe.

If we imagine that these incised lines were once filled in with some sort of dark pigment, designed to make the unusual modification stand out from a distance, it is very likely that the warrior who owned them cut a terrifying figure to the people of ancient Weymouth. 

Didn't really do him much good in the end though.

References:
http://www.bbc.co.uk/news/uk-england-dorset-14019172, pictures taken from the BBC video.

Broken!

Today I saw something I have never seen before. This happens fairly frequently, since I've only been on the planet 28 years and I've spent most of that time resolutely not looking at teeth.

When teeth suffer traumatic damage, it is most often to the enamel and underlying dentine of the tooth.  Chipping and breaking of the crown of the tooth is the kind of thing that happens when you inadvisedly pull off a bottle top with your teeth, or when you fall flat on your face on the floor catching a table on the way down.  This trauma can be very minor in nature - just a small chip or fracture - or it can result in major loss of the tooth surface and lead to the opening of the internal 'pulp cavity' of the tooth, which can lead to a lot of pain and eventual infection.

However, it is only very infrequently that you break the root of the tooth within the mandible (lower jaw) or maxilla (upper jaw) of your face.  In fact only 0.5 to 7% of  injuries to adult teeth are root fractures. Without medical intervention it is difficult to retain the tooth or for it to heal itself - normally the tooth would be lost.

But take a look at this guy...

Upper right canine from a young 17th century male.

There is a horizontal fracture across the root of the tooth, with a displacement of around 2mm. It appears that half of the tooth has been hit extremely hard from the front, causing part of it to travel backwards in the mouth - and then it simply healed, without being reset or secured in place.

It might be jumping to conclusions (which is not science, but bear with me) but since this came from a young male soldier involved in the Seige of York in 1644 - I'm thinking it was probably a fight that resulted in this damage. In fact most trauma of this is from good ol' fist fighting. A determined punch connecting to the area below the nose, could result in exactly this kind of thing.

We'll never know of course, but at least it's fun to look at - if not fun to have acquired!

Milk teeth...

...or 'Why I thought a blog might be a nice idea.'

Somewhere in the depths of a dusty lab, tucked away in an archaeology department in the north of England lurks a woman studying for a PhD in teeth.  She spends every day examining the little bundles of enamel and dentine, thinking it might be nice to share some of the things she looks at and reads every day with other people - you know, things about science and archaeology and what people in the past might have been like.

How do I know this person exists?

Because this person... is me!

Stay tuned for more interesting posts. Hopefully.