The authors newly developed custom-made regulator mouthpiece for a scuba diver using thermoforming technique to relieve and/or prevent diving-related temporomandibular disorders. And we have already confirmed that in vitro study the adhesion behavior of laminated thermoforming materials maintained for 4 weeks (672 hours) even under the 0.2-MPa pressured water environment corresponding to about 20 meters of the sea. The purpose of the present study was to assess the effectiveness of custom-made diving mouthpiece in actual undersea environment. Six collegiate divers (1 male and 5 female, mean age; 22.8 yrs), who had diving-related temporomandibular disorders or often felt jaw-muscles soreness and fatigue during scuba diving, participated in clinical trials. Changes in pain of temporomandibular joints, jaw-muscles fatigue and occlusal stability in association with the usage of new custom-made diving mouthpiece were measured on 11-point (0-10) numerical rating scale. As compared with old commercial diving mouthpiece, the custom-made diving mouthpiece significantly improved wearability, pain of temporomandibular joints, jaw-muscles fatigue and occlusal stability by 5.0, 5.7, 6.1 and 4.7 point, respectively (p<0.05). No significant changes were found in breathing difficulty, nausea and bad taste and smell. These results strongly suggested that custom-made diving mouthpiece may contribute to relieve and/or prevent diving-related temporomandibular disorders.

DESCENTE SPORTS SCIENCE Vol.32/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE