So why does toothache while diving occur? I have been diving for many years now and have from time to time come across people who report pain from their teeth while diving. This is usually followed soon after by a Facebook argument of the possible cause culminating in experts (every man and his dog) reporting things such as exploding teeth and jaws
So what is the truth behind the pain felt in teeth during a dive?
The quick and simple explanation is it’s probably just sinus pain referred to the teeth. This is due to how close the teeth are to the sinus. It could also be decay or dodgy fillings, and yes it might be a bubble under the filling expanding and contracting with the changing ambient pressure.
As a rough rule of thumb, if the pain occurs while going down, it’s your sinuses, if it occurs when surfacing, it’s your tooth.
The long answer:
Pain in the teeth caused by pressure changes is called barodontalgia. The confusion as to the cause of the pain is that barodontalgia is not a diagnosis, cause or pathology….it’s a symptom.
Just like a headache which can be caused by a multitude of different pathologies such as intracranial pressure, inflammation of the meninges, muscular tension, temperature extremes “brain freeze”,but all presenting with pain in the head.
Most odontogenic pathologies (diseases of the teeth) have the potential to cause barodontalgia.
What make things more confusing is that there are different types of barodontalgia too.
- Sharp pain during ascending is attributable to irreversible pulpitis, meaning the pulp of the tooth is alive but not for long
- Dull pain on ascent is due to reversible pulpitis, the same as above but in this case the tooth should get better on its own
- A dull pain on decent is due to a necrotic pulp meaning the tooth was already dead, and
- Severe Persistent pain that hangs around long after the dive is due to periapical pathology. Meaning the tooth probably died a while ago and now the bone around it is inflamed…go see your dentist!
The exact mechanism behind the pain is not fully understood. Many people blame air pockets left behind under fillings expanding and contracting due to Boyles law (if you don’t know what this is then get out of the water and read up on it before you get back in) and while this is possible, the more likely explanation is fluid movement in the tooth. This can be a result of exposed dentine (porous under a microscope) or decay in the tooth being exposed to pressure changes.
So what about exploding teeth!
Every diver has probably heard a story of someone’s tooth exploding or fillings falling out during a dive. And just as many have heard the explanation…the dentist left an air pocket under the filling.
So what’s the truth?
Well, leaving an air bubble/pocket/gap under a filling is not good dentistry, but it is possible. And according to Boyle’s law this bubble can expand and contract during a dive.
During decent, this bubble will contract causing a low pressure area. Low pressure in a fluid filled, porous tooth, causes fluid movement, and fluid movement in a tooth can cause severe pain.
Similarly during ascending the bubble will expand again. And this is what people usually say caused their tooth to explode (or filling to fall out)
While all this is possible, the simplest explanations are more often right. The most likely explanation for an exploding tooth or filling falling out is that the filling was ready to fall out anyway or had decay underneath it.
So when someone says, tooth pain during diving means the dentist left a bubble in your filling, or it means you have a decayed tooth etc, etc it’s as likely to be correct as someone saying your headache means you have brain freeze. Yes it’s certainly possible, but until you ask the right questions (when did you last have a slushy?) it’s all guess work.
So what’s the most likely explanation?
The most likely reason for tooth pain during diving is sinus pain. Everyone’s anatomy is different but in most people the upper teeth in the premolar to molar regions can be very close or commonly even inside the sinuses. This makes people’s ability to localise sinus and tooth pain poor. Just because you feel it in your tooth doesn’t mean it is in your tooth.
The other likely causes;
Air pressure changes in the root canal system or near porous dentine, Ischemia due to inflammation, Ischaemia due to increased intrapulpal pressure from vasodilation and fluid movement, Expansion of intrapulpal gasses produced by inflammation, Hyperaemia due to fluid movement from decompression…
What most of these explanations have in common is the presence of pre-existing pathology. You already had a dodgy tooth, diving just made you notice.
BUT…keep your sinuses clear and equalise often and you will avoid most diving “tooth” pain
Dr Saul Mendelsohn
(Diving obsessed Dentist)