|Year : 2015 | Volume
| Issue : 3 | Page : 138-140
Aviation dentistry: Past to present
Department of Pediatric Dentist, Pathak Dental Care, Karnal, Haryana, India
|Date of Web Publication||19-Nov-2015|
Department of Pediatric Dentist, Pathak Dental Care, Karnal, Haryana
Source of Support: None, Conflict of Interest: None
Airline industry has gained popularity in recent years and not much known about the dental problems associated with the high altitude. It is most common in frequent flyers, crew members, pilots etc. Due to the closed chamber pressure gets accumulated in these organs causing pain, discomfort, and organ dysfunction. The presence of dental abscesses, periodontitis, deep carious lesions and deep unlined restorations in oral cavity can stimulate severe pain due to the extreme altitude changes. With proper diagnosis, the various complications can be avoided. Thus, dentist needs to be well versed with these facts and should provide a comprehensive treatment.
Keywords: Aviation dentistry, barodontalgia, barotrauma
|How to cite this article:|
Pathak S. Aviation dentistry: Past to present. J Dent Res Rev 2015;2:138-40
| Introduction|| |
Dental care is an integral part of aircrew's operative fitness which could be jeopardized by a reduction in air density and air pressure at higher altitudes.
For the comfort of crew and passengers, aircraft pressure is maintained at high altitude by means of aircycle machines and outflow valves in spite of low atmospheric pressure outside.
Aviation dentistry is chiefly concerned with the oral and dental health status of the aviators with special emphasis on the prevention of disorders related to change in atmospheric pressure.
In the human body, various organs viz. facial sinuses, lungs, stomach, and middle ear contain gases which tend to expand at low atmospheric pressure. Due to closed chamber pressure gets accumulated in these organs causing pain, discomfort, and organ dysfunction.
The presence of dental abscesses, periodontitis, deep\ carious lesions and deep unlined restorations in the oral cavity can stimulate severe pain due to extreme altitude changes.
| Head and Face Barotrauma|| |
Barotrauma refers to the physical damage or trauma to the body tissues caused by a difference in pressure between a gas space inside the body and the surrounding fluid. It occurs commonly in scuba divers, air travellers, hyperbaric oxygen therapy, or after the the explosion due to the shock waves. It involves various conditions such as external otitic barotrauma, barotitis media, barosinusitis, barotrauma related headaches, dental barotrauma, and barodontalgia. During descend from high altitudes, partial vacuum develops which is manifested by a retracted tympanic membrane leading to barotitis and barosinusitis. Barotrauma refers to an acute inflammation of the sinus and middle ear cavities whereas barosinusitis is an inflammation of the paranasal air sinuses. The vacuum created due to air pressure difference causes mucosal edema, submucosal hematoma leading to dizziness, headache, and anoxia.
Pain and numbness can also be sequelae due to the pressure exerted on branches of the fifth cranial nerve.
| Barodontalgia|| |
Dental pain occurring due to the changes in barometric pressure is called barodontalgia. It is a symptom and not a pathologic condition itself. Most often, it is an exacerbation of preexisting subclinical oral disease. It occurs due to the entrapment of gases in the closed chamber due to which it is unable to adjust to the internal pressure. Pain is generally sharp or squeezing in nature. Pain occurring on ascend is related to vital pulp tissue and that occurring on descend is related to pulp necrosis or facial barotrauma. Pain occurring on both ascend and descend is related to the periapical disease.
The explanation for the pathogenesis of barodontalgia was given by Strohaver in 1972 where he advocated the differentiation into direct and indirect types. In the direct barodontalgia, the reduced atmospheric pressure leads to direct effect on a tooth on the affected tooth, whereas, in the indirect type, pain occurs due to the stimulation of the superior alveolar nerves at the time of maxillary barosinusitis. In the direct type, the pain is moderate to severe, which develops during take-off and is well localized and the patient can identify the involved tooth. In the indirect type, pain is dull, poorly defined involving the posterior teeth and develops during landing.
Disease of pulp is the probable cause for the pain in barodontalgia but Hodges reported that dental pain can also occur in healthy teeth during the altered atmospheric pressure.
Barodontalgia may also occur due to the expansion of trapped bubbles under a restoration causing activation of pain receptors. Referred pain to teeth can occur due to the stimulation of nociceptors in the maxillary sinus.
| Odontocrexis|| |
This condition is also known as barometric tooth explosion. Preexisting leaked restorations or recurrent caries lesions underneath restoration can cause tooth explosion when exposed to high altitude environment. Common cause of damage was the accidental expansion of gas which was trapped beneath the restorations. Calder and Ramsey reported that the tooth damage was experienced due to poor quality restorations and unrestored teeth with or without caries.
Dislodgement of crowns was due to the fractures in PFM restorations or due to the pressure changes in microtubules of dental cements.
| Dental Treatment|| |
Lack of agreement regarding the dental treatment and grounding period of aircrews for dental reasons poses a major drawback.
Lyons et al. advocated that crowns cemented with resin cement did not have reduced retention whereas those cemented with glass-ionomer cement or zinc phosphate cement had reduced retention with the tooth under environmental pressure changes.
The most common reason for this may be porosities which are incorporated during the manipulation of zinc phosphate cement and glass-ionomer cement. These microporosities expand and contract upon the pressure changes leading to weakened cement. Microleakage may also be one of the factors for low strength detected in zinc phosphate and glass-ionomer cements.
Complete maxillary dentures reduce its retention at low barometric pressure at high altitude. For edentulous fliers retention can be increased by osteointegrated dental implants.
Differential thermal contraction is seen in amalgam restoration at low temperature of a high altitude environment in comparison to tooth hard tissue. Harvey advocated that cold temperature is the prominent factor underlying dental fracture. According to Sognnaes, grinding of teeth was a causative factor for restorative failure.
There is a high-risk of caries and periodontal diseases due to the decreased salivary flow and dryness of mouth. Dryness of the mouth can be due to the breathing of dry compressed gases in the aircraft.
Rossi contraindicated the direct pulp capping in aircrew patients and advocated endodontic treatment in suspected cases of invasion to the pulp chamber in order to prevent the sub-acute pulpitis or silent pulp necrosis and their potential barometric pressure related consequences. Root canals infection if not treated may cause the leakage of the intracanal infected content to the periradicular tissues and subcutaneous emphysema.
After the extraction of maxillary teeth, dental surgeons should always rule out the existence of an oroantral communication as it can lead to sinusitis when exposed to a pressure changing environment.
| Prevention|| |
Caries excavations and restorations should be completed before air travel. Leaky restorations should be replaced. During the restoration of a carious tooth, a thorough examination of the floor of the cavity should be done to rule out any penetration into the pulp chamber. In such cases a protective cavity liner should be applied (e.g., glass-ionomer cement). During multi-visit endodontic treatment, the temporary restoration must be placed properly. When oroantral communication is diagnosed; referral to an oral surgeon for its closure is indicated.
Cuspal coverage crowns could also be a preventive measure. Resin cements are preferred for cementation, as they give better retention. During flight, chewing gum or candy will increase the salivation and prevent dryness in the mouth.
| Conclusion|| |
Due to tremendous increase in air travellers viz. pilots, aircrew personnel, air passengers, flight attendants and leisure pilots special precautions must be taken during endodontic, restorative, prosthodontic and oral maxillofacial surgical treatments for the aircrew patients to prevent any kind of in-flight incapabilities leading to serious issues. Aviation dentistry is an emerging science, which has been much neglected. The dental clinicians should take an initiative to raise awareness levels and sensitize the air travellers about this issue. The need of the hour is to promote the diagnostic tools and treatment guidelines to the aviation industry to ensure wellness of air travellers. Aviators and dentists should embrace all available opportunities for incorporating oral and dental health into aviators' physical standards, to promote their wellness.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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