Case Study: A Jaw Protruding Dental Splint Improves Running

Abstract

Wearing an intraoral jaw-protruding splint could enhance respiratory function in clinical settings and eventually exercise performance. Purpose: The authors studied the acute effect of wearing a lower-jaw-forwarding splint at different protruding percentages (30% and 50%) across a wide range of running exercise intensities. Methods: A case study was undertaken with a highly trained and experienced 27-year-old female triathlete. She performed the same incremental intermittent treadmill running protocol on 3 occasions wearing 3 different intraoral devices (30% and 50% maximum range and a control device) to assess running physiological and kinematic variables. Results: Both the 30% and 50% protruding splints decreased oxygen uptake and carbon dioxide production (by 4%–12% and 1%–10%, respectively) and increased ventilation and respiratory frequency (by 7%– 12% and 5%–16%, respectively) along the studied running intensities. Exercise energy expenditure (approximately 1%–14%) and cost (7.8, 7.4, and 8.0 J·kg−1·m−1 for 30%, 50%, and placebo devices, respectively) were also decreased when using the jawprotruding splints. The triathlete’s lower limbs’ running pattern changed by wearing the forwarding splints, decreasing the contact time and stride length by approximately 4% and increasing the stride rate by approximately 4%. Conclusions: Wearing a jaw-protruding splint can have a positive biophysical effect on running-performance-related parameters.