Abstract: An improvement to a customizable scuba-diving mouthpiece having a passageway-forming front member extending from a proximal in-mouth end to a distal outside end, and a U-shaped thermoformable back member having a forward middle portion, flanges and bite portions configured to provide moldability at substantially all points of contact between mouthpiece and teeth. The improvement includes the forming of a concave inner and outer surface on the leg portion in order to reduce jaw fatigue, the rearward termination of the inner upstanding flange substantially lateral to the diver's first molar and the tapering of the rear portions of the leg members so as to provide a more comfortable fit.

Abstract: A customizable scuba-diving mouthpiece having a passageway-forming front member extending from a proximal in-mouth end to a distal outside end, and a U-shaped thermoformable back member preferably formed in situ on the front member. The back member has a forward middle portion, flanges and bite portions configured to provide moldability at substantially all points of contact between mouthpiece and teeth such that the mouthpiece has a secure grip on the diver's teeth. The method for making such customizable mouthpiece.

Abstract: An improved customized scuba-diving mouthpiece has a base member with a front portion with breathing hole and two preferably apertured mount portions extending rearwardly for positions between the diver's teeth, and upper and lower bite members above and below each mount portion and joined together, preferably through the mount portions. Preferred features include upper and lower bite members form-set (cross-linked) together through the openings, the mount portions dimensioned to extend rearwardly between the molars to the rear of the mouth, and a configuration of mount portion and front portion facilitating buddy-breathing. A method for making such mouthpiece is also disclosed.