How Important is Dental Health for Astronauts?4 min read

Some people will go to great lengths in order to avoid a visit to the dentist office. However, if the thought of leaving the planet altogether has crossed your mind, you may need to come up with a new plan. While we might be able to put off that dental visit here on the ground, a clean bill of health regarding oral hygiene is actually a job requirement for astronauts leaving the atmosphere.

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Oral hygiene probably isn’t the first thing you think of when considering the dangers of space, but astronauts face some serious challenges related to their dental health. Here are a few things you may not have considered about the importance of dental health for astronauts.

Extreme Forces During Liftoff

The force of acceleration and vibrations during flight can be so strong, they can shake loose poorly fitting dental fillings. During a typical liftoff, astronauts have to endure a G-force of up to four times their body weight. Because of this, astronauts must go through extensive oral screenings in order to be approved for space travel.

Aside from annual exams, astronauts go through pre-flight exams at least 18 months before launch in order to determine if they may be at risk for dental conditions that would require further evaluation or emergency treatment. Based on their oral health, astronauts are classified into three categories.

Class I astronauts have good oral health and are not expected to need re-evaluation or dental treatment within 12 months.

Class II astronauts have some oral conditions present. However, these are not expected to develop into a dental emergency within the next 12 months.

Class III astronauts have at least one oral condition that is likely to result in a dental emergency within the next 12 months.

All astronauts are expected to maintain a Class II status, at minimum. However, in order to be considered for the International Space Station (ISS), all astronauts are required to have Class I status prior to launch. This is no small feat as it is estimated between half and three quarters of Americans are suffering from some level of gum disease.

Atmospheric Changes

The changes in atmospheric pressure that astronauts experience can be quite painful for someone with cavities. A condition called barodontalgia, commonly known as “tooth squeeze,” occurs when changes occur within the surrounding atmospheric pressure.

To understand this condition better, consider that gases contract or expand to match the pressure around them. This includes the air that might be present in cavities or even around ill-fitting fillings, crowns, dentures, or other dental work. Aside from astronauts, the condition may also affect deep sea divers, submariners, pilots, airline passengers, and mountain climbers.

In addition to barodontalgia, you may have heard of a phenomenon commonly known as “space bones,” in which astronauts experience a decline in bone mass while spending time in microgravity. Because an astronaut’s bones don’t need to work as hard to support their weight in space, calcium stored in the bones is broken down and released into the bloodstream. Some researchers believe this effect can also exacerbate dental health conditions.

A Long Trip to the Dentist

For the earthbound majority, it’s difficult enough to understand when your insurance will cover dental procedures, such as emergency treatments. However, astronauts face even greater complications when faced with dental emergencies. Once in orbit, an astronaut on the ISS may need to remain in space for at least six months. During this time, they will not have access to regular dental visits as a dentist has never been part of the crew of the ISS.

While there are two crew medical officers (CMOs) on board every mission on the ISS who may be able to respond to sudden dental emergencies, this is not an ideal solution. While CMOs have some training in how to deal with a variety of medical conditions, they do not have the same expertise as a licensed dentist. Because of this, CMOs would need to communicate with professionals on the ground. This presents problems of its own as one-way communication delays could take as long as 20 to 25 minutes between messages.

Because the ISS is in low earth orbit, it’s more likely that an astronaut would need to return to earth for proper treatment if facing a true emergency. Obviously, returning from a mission prematurely due to a dental emergency is not ideal.

As you can see, for astronauts, maintaining healthy teeth and gums matters much more than having a camera-ready smile. With a greater understanding of the challenges astronauts face related their oral health, you might consider yourself fortunate to have such easy access to qualified dental professionals and treatments here on earth.


Avery Phillips is a freelance human based out of the beautiful Treasure Valley. She loves all things nature, especially humans, and was driven to pursue an Anthropology degree due to her childhood love of Indiana Jones and Laura Croft. Now she lovingly writes about all things great and small.

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