Plaque and pollen and proteins, oh my!

Do you often wonder what interesting things might be lurking in your mouth when you don't brush your teeth? 

Well, wonder no more! This very interesting interview in the Guardian with Christina Warinner at the Centre for Evolutionary Medicine at the University of Zurich discusses exactly that. Warinner talks about deposits of dental plaque (what we call dental calculus) on teeth and how 'pollen, starch grains, animal muscle, bacteria, even a person's DNA' can be found trapped within it.

If you get a chance, you can watch Warinner's TED talk on YouTube (linked below), which is similarly fascinating and explains how teasing out the preserved protein and DNA from dental calculus can be used to 'investigate the relationship between disease, diet and the environment' in the past - and how that knowledge might benefit us in the future.

A Morbid Taste For Teeth

Police in Austria have recently launched a manhunt for a grave-robber with a predilection for removing teeth and dentures from crypts and coffins in the Viennese General Cemetery.

Although grave desecration is not an uncommon crime, the manner in which the perpetrator has gone about doing such a thing is a little less cloak and dagger than normal - he's apparently filmed himself opening up tombs and using pliers to remove the teeth. The composers Johann Strauss and Johannes Brahms are two of the better known victims of this not so covert dental extraction.

The Belgian media have named this individual as Ondrej Jajcaj and it would appear, from a quick perusal of his Facebook account that they might be right. Here he is in his profile picture, with a skull on a stick and a pair of pliers.

Figure 1: Ondrej Jajcaj, courtesy of his own Facebook page.
Yep. Totally normal.

Further examination of his profile reveals a 'miscellaneous' photo folder, similar to one that you or I might have, with the only difference being the sheer quantity of dental artefacts and human remains he has in there... (although it is nice to see that even grave-robbers have a fun side though. Look at him being adorable with that goat!)

Figure 2: A Facebook screen-capture. Note all the dentures and
dental fixtures. They're all pretty vintage, they are.
Wonder where they came from.

Not content with Facebook, I poked a little bit more and found his Youtube account which features a whole host of videos that I can't possibly understand, many of which show him wandering through abandoned graveyards. The video that I found most fascinating however is the ominously titled 'Gold treasure in the woods' which has him beside a tree talking about a box of gold dentures and fillings (see below) and subsequently, fragments of actual human jaw and dental instruments.

Figure 3: A half buried tin of gold teeth.
We all have one of those, right?

Figure 4: I wish I could speak Slovakian, just to
have the faintest idea what's going on here.

On what might be his website there is reference to how Jajcaj wants his amassed collection of historic dental prosthetics to be put in a museum - which he admits might not be easy since the prosthetics were from 'old abandoned graves that he illegally investigated.' His motivation is something to do with Slovakia being a Catholic country and how science triumphs over religion - but I'm not really sure exactly what he's getting at.


Jajcaj's actions are of concern. It is certainly out of the norm behaviourally - how many people regularly take topless pictures of themselves with grave-robbed spoils? But from an archaeological point of view, it is also horrible. The acts of desecration are clearly destructive, ruining the context and meaning of his 'finds'. This makes them completely pointless objects, collected for collections sake alone and at least a little for the simple gratification of an individual who thinks taking pictures like this is appropriate...

Figure 5: So many things wrong with this picture.
Again, courtesy of Ondrej Jajcaj's Facebook.

(But at least I know now that there is someone in the world more fascinated by teeth than me. Phew.)

Fashion, with teeth...

Archaeologists working near Leipzig in Germany have uncovered what appears to be the earliest example of a purse - and not just any purse, this may have been the Chanel handbag of the Bronze Age world.

Over a hundred dog teeth were found in a grave dating between 2500 and 2200 BC. The teeth were arranged closely together, in a series of  neat rows. Archaeologist Susanne Friederich believes that these canine teeth were the decoration for a purse made of leather or fabric which has disintegrated over time.

Dog teeth, lots of them.  Item is about 25cm across.
(Photo courtesy of Klaus Bentele, LDA Halle, via National Geographic)

Friederich who works for the Sachsen-Anhalt State Archaeology and Preservation Office has said that 'all that's left is the teeth. They're all pointing in the same direction, so it looks a lot like a modern handbag flap'.

Dog and wolf teeth are common finds in the prehistoric world, often found as pendants on necklaces or as hair decorations. It is likely that such ornamentation was rather fashionable for a time. However, to find so many teeth in one place and in such as ostentatious design is unusual. The bag would have required the teeth of dozens of dogs to make and in fact the sheer quantity of such teeth found in burial contexts in northern and central Europe in this period might suggest that dogs were kept more as 'livestock' than pets.

So, I suppose this discovery really is a case of handbags at dawn... at the dawn of time, that is!*




*Sorry. The puns are getting worse.


References:
National Geographic,  'World's Oldest Purse Found' 
Mz-web.de,  Staunen pur

Sex, teeth and syphilis...

Perusing through the British Dental Journal (BDJ) this morning, I noticed an article about syphilis (one of the more exciting sexually transmitted diseases) which I thought might be worth reading. From an osteological point of view, syphilis is one of the most interesting conditions to find in an individual because, left without treatment, it manifests in a number of horrible ways in the skeleton. The disease, caused by the Treponema pallidum organism eventually leads to skeletal lesions such as 'caries sicca', the pitting and whole-scale destruction of the skull through necrosis of the bone, amongst other things.

Figure 1: Caries sicca, the destruction of the frontal bone of the skull.
Image courtesy of the Cambridge Encyclopaedia of Palaeoanthropology, pp 161.

Syphilis can also be transmitted from mother to fetus, leading to a congenital form of the disease. Although it can cause a variety of developmental problems, from an osteological and dental point of view, it is the manifestation of 'Hutchinson's teeth' that are most diagnostic. The front teeth of such individuals are deformed and notched in a peculiar way - the result of particular kinds of bacteria called spirochetes inhibiting bone formation in the developing child.

So, why did the article in the BDJ inspire this blog? Mostly because it's a bit on the scary side. The cases of syphilis in the UK increased by 951% between 1999 and 2008. Although initially curable, the disease only presents a brief lesion at first (the chancre, which can appear at the point of infection), followed by a rash and sometimes - up to 50 years later - the bone changes mentioned above. Ignoring the initial appearance of the disease is probably a bad thing to do, then.

Jones et al (2012) discuss three case studies of the disease, pointing out that the initial presentation of the disease may occur in the oral cavity, in the form of a painful ulcer or lesion. Although the appearance will vary from one individual to the next, it can look a bit like this:

Figure 2: A syphilitic chancre on the tongue.
(Reprinted from the New England Journal of Medicine
without permission.  Ahem.)

The article states that the 'significant increase of syphilis and its high infectivity require the dental profession to increase their awareness of sexually infectious diseases and the appropriate dental management' (Jones et al 2012: 477), a useful recommendation, considering the rise in the number of cases in recent years.

However, I would like to increase everyone's awareness of the really horrible things that can happen if you're not careful with your sexy times. Because as fun as things might seem at the time, having your bone become infected and rot away, sending you slowing insane, probably isn't worth it in the end. So remember:

Figure 3: Yep, all of them. Including that one a few rows
back on the right. Especially him.

References:
Jones et al 2012. Three cases of oral syphilis – an overview. 
Available at: http://www.nature.com/bdj/journal/v212/n10/full/sj.bdj.2012.420.html#f2

By tooth or by beak...

Researchers at the University of Sheffield and King's College London have discovered that the pufferfish, a highly poisonous but silly looking tropical fish, may hold the key to how and why humans do not replace their teeth in adulthood - which may in turn lead to advances in dental treatments.

Certain adult pufferfish have a parrot like 'beak' with a distinct cutting edge. This beak is formed by bands of dentine which continually grow to replace those lost through feeding.  In young pufferfish, the beak is not present, instead 'first-generation' teeth develop, only to be replaced by four teeth at the front of the jaw which subsequently make-up the beak structure.

 Figure 1: A, the freshwater pufferfish, Monotrete abei. B, side-view 

showing the large lips covering the beak. C & D, views of the beak itself. 

Photo courtesy of Fraser et al (2012: 2)

According to Dr Gareth Fraser, who led the project, investigating the manner and mechanisms of tooth replacement is of  "great interest for science... to understand the genes that govern the continued supply of teeth and mechanisms of dental stem cell maintenance."

Humans only replace their teeth once, in childhood.  Unlike a shark with its many rows of teeth, or a rat with it's continually erupting ones, humans cannot replace teeth naturally. The much increased longevity of modern human populations is therefore at odds with the single set of trauma-and-disease-prone adult teeth they have. Dr Fraser believes that the knowledge could eventually be used to "facilitate advances in dental therapies" with this in mind. 



References:
Fraser, GJ, Britz, A, Johanson, Z and Smith, M. 2012. Replacing the first-generation dentition in pufferfish with a unique beak. PNAS. 
Available at: http://www.pnas.org/content/early/2012/05/04/1119635109.full.pdf+html
University of Sheffield press release. 
Available at: http://sheffield.ac.uk/mediacentre/2012/pufferfish-gareth-fraser-natural-history-museum-evolution-denistry.html

Cow collagen and gum recession...

Gum recession can occur for a variety of reasons, but it is typically associated with poor dental hygiene, over-brushing or mouth based piercings rubbing on the gums. When the loss of gum becomes severe, it is sometimes possible to use gum grafts and surgery to regenerate the gum line, preventing damage to the tooth or tooth root and improving the aesthetic appearance of the dentition.

However, recent research may have dispensed with the need for such surgery. Researchers in Germany and Switzerland have trialled the use of bovine collagen (extracted from the fluid filled sac that surrounds the bovine heart) in humans, to repair the gums of fourteen patients. The collagen was implanted next to the tooth, held in place with surgical thread and left in place to allow the bodies own cells to repair the damage (Figure 1, below).

Figure 1: Showing (A) teeth before treatment, note the multiple recessions above the teeth, (B) shows the incisions created in the gum for (C) the insertion of the collagen and finally (D) demonstrates the healed dentition at six months after intervention. (After Schlee et al. Head & Face Medicine 2012 8:6)

The results have been promising, with the functional and aesthetic appearance of the gum-line improving in many of the patients after a period of six months - in 36 of the 62 recession lesions treated for example, full root coverage was achieved.

So, as odd as it might sound, cow collagen may be the answer to gum recession for people who are unable to have corrective periodontal surgery, if longer term studies prove its staying power. Which is very moo-ving, I think you'll agree.


(Sorry about that. It's the only cow based pun I could come up with.)


References:
Schlee et al. Bovine pericardium based non-cross linked collagen matrix for successful root coverage, a clinical study in humans in Head & Face Medicine 2012 8:6  doi:10.1186/1746-160X-8-6. 
Available at: http://www.head-face-med.com/content/8/1/6
Cow collagen heals gums. Available at http://www.nature.com/bdj/journal/v212/n6/full/sj.bdj.2012.238.html.

Up to your hind teeth in work? You might want to relax a bit...

Most academics are aware that their career choice might not be very good for them - late nights, smoking, takeaway food and the occasional (okay, regular) few pints after seminars all contribute to a less than healthy lifestyle. However, recent research has revealed that your academic work might be making you unhealthy in new and interesting ways.

Researchers in Mexico have recently identified academic stress as being a risk factor for dental caries (cavities) in students. The incidence of caries was shown to significantly increase in those students exhibiting moderate or high levels of stress. The reason for this appears to be associated with a change in the normal production of saliva. 

Certain hormones produced in stressful circumstances can inhibit saliva production, and it is this decrease in saliva flow that 'reduces the protective function afforded by saliva and, in consequence, increases the risk for dental decay...' (Majia-Rubalcava et al 2012: 1). This research is the first to correlate levels of academic stress with dental health in a statistically significant way and may be eventually useful in managing and minimising the mental and physical problems caused by stress.

I'm not sure how this research might help us practically though, stress is a bit hard to avoid with teaching commitments or a thesis to write - but perhaps it's something to keep in mind the next time we're tempted to pull an all nighter, eating nothing but chocolate bars and cappuccinos to keep us going?





References:
Cynthia Mejía-Rubalcava, Jorge Alanís-Tavira, Liliana Argueta-Figueroa and Alejandra Legorreta-Reyna. 2012. Academic stress as a risk factor for dental caries. In the International Dental Journal DOI: 10.1111/j.1875-595X.2011.00103.x