Popping ears and difficulty breathing are not the only physical effects felt when you go higher. Your teeth are also affected by an increase in altitude. While the body is used to functioning close to sea level, when you climb to 2,000m (6,500ft) or more it needs to adapt. A change in oxygen levels and air pressure at high altitude can affect the teeth of pilots, air passengers, mountaineers, skiers and hikers.
A rise in elevation may cause barodontalgia, a painful condition affecting teeth caused by changes in pressure and the aggravation of existing dental problems. Pockets of gas within tooth cavities or areas of tooth infection expand as air pressure gets lower, but the tooth cannot enlarge to accommodate this change in pressure. In addition, the cold air at high altitudes also makes broken cavities painful.
You may feel a sharp or squeezing pain in the tooth when suffering from barodontalgia at high altitudes, caused by the build-up of pressure pushing on fillings, infection or exposed root canals. These kind of "dental pains provoked by an altitude beyond 5.000 ft can occur with any kind of tooth, healthy or restored,” according to researchers Fleury and Deboets.
The effect of pressure changes on acute tooth root infection and recent treatment for root canal repair can cause high-altitude illnesses such as pulmonary oedema, according to a study published in the Postgraduate Medical Journal. Teeth may even fracture at high altitudes, say Zadik, Einy et al in the June 2006 issue of Aviation, Space, and Environmental Medicine. Pilots risk being disabled by intense tooth pain, causing potential safety problems for passengers, while leisure travellers suffer an uncomfortable holiday.
The key to preventing tooth pain at altitude is good dental health, say Robichaud and McNally in the Journal of the Canadian Dental Association 2005. Because the effects of altitude are heightened when your teeth are in bad condition, you should visit your dentist before you undertake any high-altitude flights or leisure activities to check the condition of fillings and general tooth health. When travelling at altitude ascend slowly so your body has time to adapt and spend a few days acclimatizing before climbing above 3,500m (11,000ft). Drink plenty of fluids but avoid alcohol, and immediately descend if you are experiencing tooth pain or discomfort.