Thursday, 28 June 2012

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

Tuesday, 29 May 2012

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



Thursday, 10 May 2012

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





Tuesday, 27 March 2012

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.

Tuesday, 20 March 2012

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

Wednesday, 25 January 2012

Tooth and beauty

The role of the media in the well-being of young people in the West has been much discussed in the past few decades, with the popularity of glossy magazines and the exuberant application of Photoshop in them suggested as compounding factors in the rise of eating disorders and cosmetic surgery.

However, looking through some old advertisements for dental products today I realised that not a great deal seems to have changed in the last half century or so. This Colgate toothpaste advertisement came out in 1947:


Apparently even in the 1940s, manufacturers were focussing on what sells - the fear of social exclusion and not being loved. The woman featured is destined to be alone and to be the target of hushed gossip, all because she doesn't use the right toothpaste. Compare this to any clothing, car or perfume advert on television now, which all promote an in-crowd and how a particular product can make you part of it.

The reference to 'scientific tests' is quite good too, with 7 cases out of 10 of 'Oral Offence' being prevented by using Colgate Dental Cream. Sounds about as scientific as the wonderfully named 'nutrileum' and 'pentapeptides' and so on which animatedly feature in modern shampoo adverts, eh?

Friday, 6 January 2012

Death by Mortification

During the 16th and 17th centuries, plague swept through England causing huge changes to the size and make-up of the population. It was deemed necessary for the first time, to record the numbers and nature of deaths in the capital. The first record of this type commenced in London on January 1st 1564 and ended the last day of December the following year. In that time 23,630 deaths were recorded, 20,136 of which were listed as plague deaths.

Cause of death continued to be recorded in subsequent years, eventually forming the 'London Bills of Mortality', which, whilst lacking a certain medical expertise, certainly provide a good read.  Look at this one from 1806 / 1807. Some recognisable causes of death are present; small pox killed 1297 people, old age carried off 1424 and cancer 83 for example.

However, there are a few odd and unusual ones worth mentioning. Mortification (the death of part of the body, probably in the manner of gangrene) did away with 210 individuals, whilst the Rising of the Lights (a spookier sounding condition there is not) killed one unlucky Londoner. Saint Vitus's Dance, an infectious disease causing jerky movements, also killed a single person. Four unfortunate people were apparently Frighted to death.

Of interest to me (of course) are the deaths attributed to 'Teeth', which amounted to 322 in 1806. Teeth were therefore the tenth most common cause of death that year. In other years 'teeth' made it to the fifth or sixth most common cause of death with hundreds dying from infections originating from abscesses and advanced gum disease. If we compare this to the modern day, deaths from tooth based infections are very rare - just eight people in the UK had dental related deaths in 2005. Oddly though, that's four more than were killed by some kind of unspecified 'Evil' two hundred years earlier...