This has been called aerodontalgia when applied to altitude exposure. Gas spaces may exist in the roots of infected teeth, along dying nerves, in necrotic areas of the pulp, and alongside or associated with fillings which have undergone secondary erosion (it is one of the main Dental Barotrauma Causes).
The gas may enter around the edge of the filling, adjacent to the tooth or through micro fractures of the enamel and dentine (aerodontalgia factor).
Teeth with full cast crowns may be susceptible to air being forced into the cemented material between the crown and the tooth - especially if cemented with zinc phosphate cement or, to a less extent, glass ionomer cement. Micro leakage of gas is less evident with resin cement.
During descent, the contracting gas space is replaced with the soft tissue of the gum or with blood and effusion. Pain may prevent further descent (dental barotrauma causes). If, because of slowed descent, symptoms are not noticed, then gas expansion on ascent may be restricted by the blood in these spaces, resulting in distension and severe pain.
Because of the aetiologies (aerodontalgia) described above, the dental barotrauma is often encountered in older divers, who sometimes experience dental barotrauma reliably at a constant depth - but often without the gas space able to be readily visualized on X-ray. Transillumination with a high-intensity light may reveal the micro fractures.
Another presentation of dental barotrauma occurs in cases involving a carious tooth with a cavity and very thin cementum. As pressure differences across the cementum develops, the tooth may cave in (implode) on descent, or explode on ascent, causing considerable pain. Fast rates of ascent or descent will tend to precipitate this. Pressure applied to individual teeth may cause pain and identify the affected tooth. Sensitivity to cold may also localize the tooth.
A third form of dental barotrauma (aerodontalgia) involves the tracking of gas into tissues, through interruptions of the mucosa, e.g. diving after oral surgery, dental extractions or manipulations. Scuba regulators result in positive oral pressure, forcing gas into tissues.
Dental barotrauma showing collapse of the first right bicuspid during a dive to 20 metres. Previous dental treatment converted an open cavity into one covered by a silver amalgam filling.
Preventive measures include (you must learn about dental barotrauma causes): biannual dental checks (including X-ray examinations if indicated), avoidance of all diving after dental extractions and surgery until complete tissue resolution has occurred (i.e. intact mucosal surface), slow descent and ascent.
Dental barotrauma treatment consists of analgesia and dental repair. The differential diagnosis of sporadic or constant pain in the upper bicuspids or the first and second molars, but not localized in one tooth, must include other dental disorders as well as referred pain from the maxillary sinus or the maxillary nerve (best diving). This may also present as a burning sensation along the mucobuccal fold.