First Stop for SCUBA DIVERS: The Dentist’s Office?

“There are as many as 6 million active Scuba Divers worldwide.” Scuba diving is becoming more and more popular and we as the dentists are increasingly likely to encounter patients with diving-related problems. As, the teeth and mouth are very involved in Scuba Diving. If either is in poor health or is not treated properly, one can find himself with jaw joint pain, gum tissue problems, or 'tooth squeeze' — pain in the center of the tooth caused by changing pressures,"

The aim of this article is to introduce Diving Dentistry followed by practical recommendation for prevention and management of the dental conditions associated with diving and to address diving barotrauma to oral region. The relevant common conditions for dentists who treat divers include dental barotrauma (barometric-related tooth injury), barodontalgia (barometric-related dental pain), mouthpiece-associated herpes infection, pharyngeal gag reflex and temporomandibular joint disorder (dysfunction).

Dental Barotrauma v/s Barodontalgia

Dental Barotrauma can manifest as tooth fracture, restoration fracture (both will be referred as dental fracture), and reduced retention of dental restoration. Other than need for dental treatment, potential consequences include aspiration or swallowing of the dis- lodged restoration or dental fragment, and pain, which may lead to incapacitation while diving and premature discontinuation of the planned dive.

The term barodontocrexis (barometric-induced ‘tooth explosion’, Greek) describes the phenomenon of dental fracture. Dental barotrauma occurs while ascending; upon surfacing after completing the dive, the diver may report that a tooth broke or has shattered. Dental barotrauma can appear with or without pain, similar to dental fracture occurring at ground level.

 Preventive measures to avoid Dental Barotrauma:

1. Pre dive visit to dentist for preventive measures and periodically for occult pathologies, such as leaked restorations and secondary caries lesions.
2. For prevention of dislodgement and aspiration, it is advised not to dive while having provisional restorations or temporary cement in the mouth.
3. Since dislodged partial removable prostheses could be accidentally aspirated during diving these devices should be removed before diving, unless they are securely retained.
4. Retention by adequate osteointegrated dental implants is probably the best resolution for edentulous divers. Alternatively, a ‘custom edentulous mouthpiece’ which combines a mouthpiece with a prosthesis, is also offered.

Barodontalgia is an intraoral pain evoked by a change in barometric pressure, in an otherwise asymptomatic oral cavity. In a diving environment, this pain is commonly called tooth squeeze. Although rare, in-diving barodontalgia has been recognized as a potential cause of diver vertigo and sudden incapacitation, thus could jeopardize the safety of diving. Barodontalgia is a symptom rather than a pathologic condition itself and in most cases reflects a flare-up of pre-existing subclinical oral disease.

 Most of the common oral pathologies have been reported as possible sources of barodontalgia, with faulty dental restorations and dental caries without pulp involvement (29.2%),necrotic pulp ? periradicular inflammation (27.8%), vital pulp pathology (13.9%) and recent dental treatment (postoperative barodontalgia, 11.1%) being the most common.

 Barodontalgia due to barotrauma is unique because it arises during diving, rather than acts as a flare-up of a pre-existing condition. Barodontalgia is classified as direct (dental induced) and indirect (non-dental induced) pain.

 Preventive measures to avoid Barodontalgia:

1. Periodic examination, including periapical radiographs and vitality tests, is suggested for the prevention of barodontalgia in divers, with special attention to apical pathology, faulty restorations and secondary caries lesions.
2. Pre dive visit to dentist for examination of the cavity floor to rule out penetration to the pulp chamber and get a protective cavity liner application done. (e.g. glass-ionomer cement).
3. During multi-visit endodontic treatment, it is a must to confirm that the restoration is intact before diving. In a pressure- changing environment, open unfilled root canals may cause subcutaneous emphysema, as well as leakage of the intra canal infected content to the periradicular tissues.
4. During surgery in the posterior upper arch, especially when the sinus is augmented, the role of dentist is rule out the existence of oroantral communication, which can lead to sinusitis and potentially adverse consequences upon exposure to a pressure- changing environment. When oro-antral communication is diagnosed, referral to an oral surgeon for its closure is indicated.
5. Temporary diving restriction after dental and surgical procedures is still a powerful tool for prevention of postoperative barodontalgia.
6. Patients should not dive within 24 hours of a restorative treatment requiring an aesthetic and within at least seven days of having surgery. In suspected or actual oro-antral communication, diving should be restricted for at least two weeks.
7. Until otherwise indicated, the cautious dentist may consider all sinus augmentation procedures as potentially inducing oro-antral communication. Thus, the dentist may recommend a longer restriction of diving to prevent failure of the procedure and pain during diving.
8. Before diving is allowed after extraction, implantation and ? or sinus augmentation, it is reasonable that the patient be invited back to the office for verification of wound healing and an absence of signs or symptoms of sinus inflammation.

 Mouth- Piece related conditions

The diving mouthpiece has obvious relevance to oral tissues and conditions. The scuba diver gets air from a compressed air tank, which is transmitted to the mouth via a regulator with a mouthpiece that is held by the teeth (usually the canines and premolars). An airtight seal has to be created between teeth and lips. Inability to hold the mouthpiece due to complete or partial edentulism is one of the contraindications for scuba diving.

 Air pushing by mouthpiece into post-surgical wound may induce intraoral pain, mimicking barodontalgia. Owing to the helium in scuba tanks and the resulting lower gas viscosity, air from the pressurized tanks can be forced in through carious lesions and defective margins of restorations as well.

 The diving mouth- piece acts as a possible vector for transmission of herpes simplex virus between mates, especially during under- water drills, in which the mouthpiece is exchanged frequently between participants to simulate emergency conditions.

 Mouthpiece-associated pharyngeal (gag) reflex during depth diving, when accompanied with stress (which is relatively common during diving), often causes the diver to perform a quick escape to surface level   (a ‘panic ascent’). This maneuver may cause DCS.

 Pre-existing TMJ problems may be worsened by the use of a diving mouthpiece, but symptoms may appear even in previously symptom-free divers. TMD symptoms were more prevalent in diving in cold water than in warm water, probably because of the impairment of the lips’ contracting capability in the cold environment, thus enforcing over-effort of the masticatory muscles.

 Diving related TMD symptoms, also called Diver’s Mouth Syndrome (or regulator mouth), may include all the TMD symptoms (e.g. muscle pain, joint pain, internal derangement of TMJ-disc, headache) in various degrees, and may be limited to diving time or become chronic and constant. These symptoms are attributed to the protruded mandibular position and the biting force exercised on the anterior occlusion (usually canines and premolars) during diving.

A semi-customized mouth- piece required less muscle activity for retention than commercial type, and fully customized mouthpieces are reported to cause the least mandibular displacement from the normal resting position, thus usage results in the least discomfort, muscle pain, fatigue and effort.

 Dental implications:

• To prevent post-surgical forcing of air into the tissues and dry socket, diving should be restricted for at least one week following oral surgery; prior to diving the dentist should confirm healing.
• The dental team must educate the diver patient of the infectious potential of the mouthpiece and recommend using only a private one, and encourage maintenance by hygiene procedures after each use, similar to other removable oral devices. The diver should not dive in times of illness, for the concern of his or her mate.
• Possible solutions for divers with prominent pharyngeal reflex include: avoidance of personal gagging contributing factors (e.g. anxiety, stress), desensitization training (repeated introduction of devices to the sensitive region), trimming the intraoral trigger parts in the mouthpiece, or use of the (more expensive) full face mask. Anti-gagging medications should not be taken before diving to avoid a possible hazardous effect.
• Diving related TMD symptoms should be differentiated from barotitis symptoms. Despite the potential limitations in the construction process because of the number of stages involved, the greater expense and the possible reluctance of experienced divers to change from the standard commercial mouthpiece.
• However, if a custom mouthpiece is not an option, the diver should remember that there are design differences between manufacturers. Thus, when choosing his or her equipment, the diver should test out (in a trial dive) a number of mouthpieces in order to find the design with the least likelihood of causing joint symptoms; at least 15 minutes of diving followed by a rest period of 15 minutes, and adequate disinfection of devices between trials.

 REFERENCES:

1. Zadik Y. Dental barotrauma. Int J Prosthodont 2009;22:354– 357.
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3. McDonnell JP, Needleman HL, Charchut S, et al. The relation- ship between dental overbite and eustachian tube dysfunction. Laryngoscope 2001;111:310–316.
4. Bierman HR, Brickman IW. The relationship of dental maloc- clusion to vacuum-otitis media and the use of dental splints during descent from altitudes. Ann Otol Rhinol Laryngol 1946;55:5–12