Airway efficiency during the use of SCUBA diving mouthpieces.

OBJECTIVE To investigate the effect of varying interdental bite platform thickness of the scuba mouthpiece on airway efficiency. METHODS 10 male divers had their mean peak flow measured for free breathing, maximum flow with diving mouthpiece, teeth in occlusion, and for five experimental mouthpieces with different thickness of interdental bite platform (1 mm, 2 mm, 3 mm, 4 mm, and 5 mm). RESULTS The connecting airway between the demand valve and mouthpiece was found to be a major limiting factor in airway efficiency. An interdental bite platform of 4 mm resulted in the greatest air flow with a further increase in thickness resulting in air flow restriction. CONCLUSIONS The use of an interdental bite platform of 4 mm placed between the premolar and molar teeth ensures the greatest airway efficiency and also results in a design which provides the least temporomandibular joint discomfort for the diver.