In the 19th Century, a Pennsylvania dentist called WH Atkinson came across a condition that sounds like the stuff of nightmares. Writing in The Dental Cosmos, the first major journal for American dentists, Atkinson documented an outbreak of exploding teeth.
He saw it in three patients. The first, the Reverend DA from Springfield, went through this unpleasant ordeal in 1817:
The right superior canine or first bicuspid commenced aching, increasing in intensity to such a degree as to set him wild. During his agonies he ran about here and there, in the vain endeavor to obtain some respite; at one time boring his head on the ground like an enraged animal, at another poking it under the corner of the fence, and again going to the spring and plunging his head to the bottom in the cold water.
Not terribly dignified behaviour for a clergyman, which gives you some idea of how much pain he must have been in. Toothache could be sheer torture in the era before cheap and effective dentistry: an inquest in Sussex in 1862 heard how a man took his own life after a toothache lasting five months, “during which time he was observed to cry, day by day, for hours together”. The unfortunate priest had a happier outcome:
All at once a sharp crack, like a pistol shot, burst his tooth to fragments, giving him instant relief
All proved unavailing, till, at 9:00 the next morning, as he was walking the floor in wild delirium, all at once a sharp crack, like a pistol shot, bursting his tooth to fragments, gave him instant relief. At this moment he turned to his wife, and said, “My pain is all gone.” He went to bed, and slept soundly all that day and most of the succeeding night; after which he was rational and well.
Did the metals in early fillings react to release a build-up of hydrogen that exploded in the patients' mouths? (Credit: Alamy)
Thirteen years after this distressing incident, something similar happened to a patient known as a Mrs Letitia D, who lived only a few miles away. She suffered a prolonged toothache, “terminating by bursting with report, giving immediate relief”.
The final case in this trio of dental disasters occurred in 1855. Mrs Anna PA reported that one of her canines split from front to back:
A sudden, sharp report, and instant relief, as in the other cases, occurred in the left superior canine. She is living and healthy, the mother of a family of fine girls.
Although unusual, these stories are not unique. The editors at the British Dental Journal recently highlighted a lively correspondence from its archives, originally printed in 1965, detailing many other tales of detonating dentine throughout history.
The molar burst with a concussion and report that well-nigh knocked her over
They included a case recorded in 1871 by another American dentist, J Phelps Hibler. He treated a young woman whose toothache ended spectacularly when the tooth, a molar, “bursted with a concussion and report, that well-nigh knocked her over”. The explosion was so loud that she was deafened for some days afterwards.
Although there were five or six reported cases in the 19th Century, there has been no documented case of exploding teeth since the 1920s. Hugh Devlin, Professor in Restorative Dentistry at the University of Manchester’s School of Dentistry, says that although it is fairly common for diseased teeth to split, he’s never heard of one going bang. He recalls that Antarctic explorers in the 1960s reported their teeth shattering spontaneously, thought at the time to have been the result of extreme cold – but he believes the real culprit was caries (tooth decay) caused by their high-sugar diet.
So what caused these dramatic dental explosions? In his 1860 article Atkinson offered two alternative explanations. The first was that a substance which he called ‘free caloric’ was building up in the tooth and causing a dramatic increase of pressure in the pulp. This hypothesis can be ruled out straight away, since it relies on an obsolete scientific theory. For many years, heat was believed to consist of a fluid called ‘caloric’, which was self-repelling – although this would make a pressure increase plausible, we now know that no such fluid exists.
Without understanding the cause of the exploding teeth, we cannot be sure that it will not afflict another patient in the future (Credit: Alamy)
At first glance, Atkinson’s second idea seems more credible. He suggested that decay within the tooth might have caused a build-up of gas, which eventually made the tooth fracture.
Could this explain the mystery? Devlin is sceptical: “It is highly unlikely that gas could build up in a tooth sufficient to cause it to explode – teeth are extremely strong. The 19th Century dentists didn’t understand caries – they thought it came from within the tooth. It’s only in the last century that we started understanding that caries is caused by diet and by bacteria building up on the surface of the teeth.”
A poorly executed filling could create an electrochemical cell – effectively, the whole mouth would be turned into a low-voltage battery
Instead, the answer may lie in the chemicals used to make early fillings. Before the advent of mercury amalgam in the 1830s a wide variety of metals were used to fill dental cavities, including lead, tin, silver and various alloys. Andrea Sella, Professor of Inorganic Chemistry at University College London, points out that if two different metals had been used this would create an electrochemical cell – effectively, the whole mouth would be turned into a low-voltage battery: “Because of the mixture of metals you have in the mouth, there might be spontaneous electrolysis. My favoured explanation is that if a filling were badly done so that part of the cavity remained, that would mean the possibility of build-up of hydrogen within a tooth.”
An already weakened tooth might conceivably burst under this pressure – and the hydrogen could even explode if ignited, for instance if the patient were smoking at the time or if an iron filling caused a spark in the mouth. Sella concedes that this scenario is a little far-fetched: “My feeling is that there wouldn’t be a jet of flame coming from this Victorian gentleman’s mouth.”
Unfortunately, there’s no evidence that any of the original patients actually had fillings. So either an unknown process was causing the explosions or the patients were exaggerating symptoms which were far more mundane. For now at least it seems that the “mystery of the exploding teeth” will remain unsolved.
---
This article was based on a post on Thomas Morris’s blog on the history of medicine, which can be found at www.thomas-morris.uk. He tweets at @thomasngmorris.
Join 500,000+ Future fans by liking us on Facebook, or follow us on Twitter, Google+, LinkedIn and Instagram.
If you liked this story, sign up for the weekly bbc.com features newsletter, called “If You Only Read 6 Things This Week”. A handpicked selection of stories from BBC Future, Earth, Culture, Capital, Travel and Autos, delivered to your inbox every Friday.