The recent launch of Elon musk’s SpaceX in March 2020 and many similar frequent space expeditions, gives rise to today’s era- THE SPACE ERA. Space medicine is now a highly researched and emerging branch of science in this space era. Human body is well accustomed to gravity changes on earth. Under such conditions the normal functioning of the human body tissues & the oral tissues takes place at 1-g( gravity) i.e exposure to a routine environment.This behaviour of general body tissues & oral tissues gets totally altered when they are exposed to the situations of microgravity to almost 0-gravity.. This brings forth the possibility of a newly emerging branch of future ‘’AEROSPACE DENTISTRY’’ where the dentists will have a pivotal role to play.
Fig: Skylab 2 Commander Charles Conrad (right) submits to a dental examination by Crew Medical Officer Joseph Kerwin in the Skylab Medical Facility. (DTI/Photo courtesy of NASA, USA)
REPORTED DENTAL EMERGENCIES IN SPACE
In 1978, Soviet cosmonaut Yuriy Romanenko during a 96-day flight of Salyut 6 experienced a toothache. Crewmembers pleaded for help from the ground as Romanenko’s problem worsened. The Soviet space program had no contingency plans for dental emergencies; the advice from controllers was “take a mouthwash and keep warm.” Romanenko, “his eyes literally rolling with pain” (Wheatcroft, 1989, p. 7), He suffered for a period of two weeks before Salyut 6 touched down on schedule. His ordeal was the subject of a televised interview in the Soviet Union, as well as published accounts in Russian and U.S. space and dental literature.
Cosmonauts have also reported lost fillings and crowns in-flight that were thought to be dislodged by the vibrations and effects of barotrauma associated with launch. Nine anecdotal reports of cosmonauts experiencing dental pain inflight have also been reported.
Pulpitis is documented and reported within 90 days of launch, both pre flight and post flight journeys. Pulpitis is inflammation of dental pulp tissue,which has bacterial, mechanical, thermal, and chemical etiology.
It also focused attention, including that of NASA, on the need to address the possibility of debilitating dental emergencies in space. Still, good teeth and a history of preventive care cannot guarantee that no caries will develop in anyone over the course of a 3-year mission.
Why astronauts must take oral health seriously?
Some factors that could contribute to the development of tooth and gum disease include changes in bacterial flora in the mouth, inattention to good dental hygiene, changes in food consistency because of the consumption of dehydrated space meals, and lack of foods with natural gingival cleansing properties.
FIG: ORAL HYGIENE KIT COMPRISING OF
EDIBLE TOOTH PASTE TOOTH BRUSH
AND WATER BAG.
The committee has learned that NASA is developing new, prevention-oriented dental protocols for space shuttle missions and the ISS and that these are undergoing internal agency review. (M.Hodapp, NASA, personal communication, April 10, 2000).
For a 3-man, 28-day mission, such as the Skylab 2 mission,(when it started and launched) a 0.92 percent risk was calculated for an in-flight dental event capable of significantly impairing a crew member’s productivity.
A Current data from the IMM (Integrated Medical Model)estimate the following incidences (in events per person-year) as following:
1.Dental carries 0.39 (SD 0.0234),
2.Dental abscess of 0.0230 (SD 0.00590),
3. Exposed pulp of 0.0201,
4.Dental avulsion 0.00292,
5.Dental crown replacement of 0.00518, and
6. Dental filling replacement of 0.00511. 2
An analysis of all medical conditions within IMM found that the medical condition most likely to end in evacuation from the International Space Station would be a ‘’Dental Abscess’’.
Procedure of oral health care examination in astronauts:
A pre-flight dental examination has to be done priorly 18 to 21 months before launch. During this exam, the astronaut undergoes a thorough clinical and radiographic exams.. All necessary treatment is then to be completed 90 days prior to launch.A meticulous oral hygiene routine during flight is also expected to be followed by the astronauts.
Also ,astronauts undergo a thorough oral exam annually. On the basis of such examinations classification of astronauts is done to determine their eligibility for space missions.
Classification is done into three categories: Class I astronauts have good oral health and are not expected to require dental treatment or re-evaluation for 12 months, Class II astronauts have few oral conditions left untreated are not expected to result in a dental emergency within 12 months,
and Class III astronauts have an oral condition which, left untreated, is expected to result in an emergency within a period of 12-months. A minimum of Class II status, and only astronauts with Class I status prior to launch are considered for the ISS is a must requirement for any astronaut.
Types of Dental Equipments can be used in space:
A high-definition intra-oral camera system, a method for detecting interproximal decay and osseous infections while limiting radiation, as well as a battery-operated dental handpiece and headlight.
Material considerations include an Intermediate restorative material that is easy to use, does not require special equipment for mixing or curing, releases fluoride, and could last for the duration of an exploration-class mission.A Glass ionomer restorative material is also under consideration, although this would require special packaging to allow for controlled mixture by hand in a microgravity environment.
Atraumatic restorative treatment (ART), which may represent one potentially useful approach to the management of dental lesions in space. ART is a conservative approach to caries management, where a carious tooth tissue is removed with hand instruments instead of electric rotating handpieces.
Discussion about medications indicated that all drugs to be freshly manufactured would require special packaging to maximize shelf life, especially those medications that are sensitive to moisture and radiation. Software considerations include training videos for the crew members to review and train
My Perspective on Dental practice in Space missions
- As history reported chances of developing a Dental abscess is high due to bacterial infection in astronauts, it gives the dentist a food of thought, as to re-evaluate the use of micromotor, suction tip,other dental equipments which will not follow same Principles of grasping instruments in absence of gravity.
- Without the luxury of gravity Principles of filling restorative materials in dentistry needs to be questioned and pondered upon.
- Ergonomics of Dental practice , which comprises dental chair positions, light adjustment, body posture will be highly compromised.
NASA is now looking ahead to longer-duration space missions, initially in Earth orbit and later into deep space. Mars mission by Elon musk, and colonization on mars and moon is now becoming future reality. Over the next decade, a number of astronauts will have 3-to 6-month tours of duty aboard the International Space Station (ISS).Exploring the dental health, prevention and maintenance of oral health will play great opportunity for every aspect of it and including newer subjects like Aerospace dentistry opens the door to innumerable possibilities as oral health is equally important as compared to the general health of an astronaut.
