The maintenance of dental health should be of prime importance to the diving enthusiast. Dental conditions such as barodontalgia, joint and facial muscle pain and the use of prosthetics are concerns worth considering before diving.
You are probably asking yourself, “What has dentistry got to do with diving?” Granted, one of the last things divers think about when preparing for that long awaited trip is whether their teeth and jaws are up to the journey. But, if you stop to think about it, unless you are a whale or a dolphin, your mouth is your connection to the scuba gear that allows you to breathe underwater. Let’s take a look at some of the dental problems facing divers and how to prevent or treat them. The dental concerns of scuba diving fall into three main categories, barotrauma, muscle and joint pain and divers who wear full or partial dentures.
As you learned in your certification course, scuba is a respirator that uses compressed air to inflate the lungs, compensating for the increased atmospheric pressure of the underwater environment. For example, 90 feet below the surface a diver’s lungs would have a volume of only one-quarter of what they would have at the surface. If this diver held a full breath and ascended directly to the surface, the volume of air in the lungs would expand by a factor of four and, in essence, the lungs would burst. This is an example of barotrauma.
The same phenomenon of compression and expansion of air can occur in teeth and is referred to as barodontalgia – tooth squeeze. Any condition that allows air to enter the interior of a tooth can cause barodontalgia, including decay, defective margins of restorations (crowns, fillings or inlays), periodontal abscesses (infections of the gums and bone supporting the teeth), sinus congestion, pulpal (nerve) infection or injury and endodontic (root canal) therapy.
Decayed teeth, defective fillings or teeth that have been opened for root canal treatment and temporarily sealed have been known to fracture or, in rare cases, explode from air expansion upon surfacing. This fracturing, referred to as odontecrexis, is more common in deep divers using heliox mixtures. This condition has been experimentally demonstrated by British pathologist Dr. Ian Calder. I have personally observed a case in which a diver had a full porcelain molar crown shatter while ascending from 65 feet.
Increased pressure can cause decayed teeth to ache by forcing fluid in the inner structure of the tooth (dentin) to press on the main nerve.
Sinus squeeze, which usually results from attempting to dive with plugged nasal passages, can result in extreme pain in one or more of the upper back teeth. This pain can mimic an abscessed tooth and last for several hours. Sinus squeeze usually resolves itself.
A common diving dental problem I have observed is the loss of gold and porcelain that is bonded to metal crowns. I suspect that expanding trapped air may be quite an efficient crown remover for teeth where the cement bond is failing.
A periodontal abscess is a painful swelling of the gum tissue surrounding a tooth, increased atmospheric pressure compresses the swelling and aggravates the condition.
Individuals who are actively engaged in scuba diving or are contemplating entering this sport should maintain meticulous oral health. To avoid barodontalgia, all cavities should be filled, ill-fitting crowns replaced, active gum disease treated and root canal therapy completed.
Muscle And Joint Pain
The typical scuba mouthpiece is made of neoprene or silicone rubber, which is held in place by bite tabs that fit in the canine and bicuspid areas of the mouth. These few teeth must support the weight of the regulator’s second stage. The drag of the water against the second stage as the diver swims results in considerable clenching of the jaw muscles during the 40 to 60 minute length of an average dive. Many divers experience headaches and facial muscle pain from this non-stop struggle. In the case of temporomandibular joint disease (TMJ) sufferers, the results can be especially devastating.
Research has shown that extending the bite tabs to also cover the molars serves to better balance the weight of the regulator and relieve stress on the jaw. Unfortunately, very few mouthpieces with extended bite tabs are available commercially.
Dentists can do a great service for divers by constructing a custom mouthpiece that provides coverage for the back teeth. For this technique a standard silicone rubber mouthpiece is used as an impression tray. Silicone putty impression material is placed on the bite tabs of the mouthpiece, the diver places the mouthpiece in his or her mouth and bites down normally. The diver can mold the soft impression material with the tongue and the dentist can assist by molding with the cheeks. The impression is sent, along with plaster casts of the diver’s teeth, to an orthodontic laboratory where an entirely new mouthpiece is fabricated from silicone rubber.
Full Or Partial Dentures
Wearing full or partial dentures while diving is a very dangerous practice and should be avoided at all costs. Partial dentures are frequently a problem as they can be dislodged and inhaled or swallowed more easily than full dentures because of their size. However, Dr. Calder, a pathologist, presented an interesting case of a 30 year old man who was retrieved from the bottom of a swimming pool during a diving class. CPR was commenced with difficulty. The patient was eventually pronounced dead. No one had appreciated either the absence of the dental plate or the possible presence”. Cause of death was asphyxiation owing to obstruction of airway by a full upper denture.
To completely eliminate the chance of dislodgement and swallowing, a custom mouthpiece must be made. Once again, a silicone rubber mouthpiece is used for the impression. In the case of a completely toothless diver I prefer to use a Comfo-Bite brand mouthpiece as its design provides support in the upper front area of the mouth for the silicone putty impression. In this case, the diver holds the putty to the roof of the mouth with the tongue until it is set. Full arch impressions are taken and, again, all is sent to a laboratory where a custom mouthpiece is made.
Dental problems in sport scuba diving generally fall into three categories: barodontalgia, joint and facial muscle pain, and prosthetic considerations. Barodontalgia may be avoided by proper fillings, replacement of leaking crowns, treatment of active gum disease and completion of root canal therapy prior to diving. Custom mouthpieces should be made for divers with facial and jaw joint pain and for the safety of divers who wear full or partial dentures.