Intervention Effect of Occlusion on the Straight Jump in Trampoline Gymnastics: Effect on T-score and H-score

The purpose of the present study was to clarify the effect of an occlusal intervention involving a mouthguard on the T-score and H-score of straight jumps in trampoline competitions. The participants were 15 male trampoline gymnasts (17.6±2.5 years). Custom-made mouthguards were fabricated using a 2.0-mm-thick ethylene-vinyl acetate thermoplastic elastomer, and that were fitted to the participating trampoline gymnasts and adjusted so that all teeth made equal contact when the mouth was lightly closed. The gymnasts were instructed to wear the mouthguards about half the time during their six practice sessions per week. The trial comprised 10 consecutive straight jumps. Flight time (T-score) and landing position (H-score) were recorded using the HDTS all-in-one measurement system. Measurements were taken at three time points: before the mouthguard intervention, immediately after intervention, and 2 months after the intervention. Comparisons of T-score or H-score by measurement time point were analyzed using one-way analysis of variance with repeated measures or Friedman test, respectively. The T-score was observed between the before intervention and 2-month time points (P<0.01). The H-scores increased with the mouthguard intervention, with significant differences observed of the before intervention time point with the immediately after intervention (P<0.05) and 2-month (P<0.01) time points. The results of the present study suggest that an occlusal intervention involving a mouthguard affects flight time and landing position in straight jumps in trampoline competitions. The effects on the H-score were evident immediately after intervention, and the T-score was improved 2 months after the intervention.