Abstract
Dental occlusion may affect static and dynamic balance. The effects of a
mouthguard on pinpoint accuracy in volleyball were investigated in 28 players
who completed a volleyball specific test. Also, masticatory electromyographic
tests were performed. The mean pinpoint accuracy was significantly higher with a
mouthguard (68.6±9.3 vs. 64.0±7.0 points from 100; p<
0.006). However, differential mouthguard effects were seen, and three subgroups
were classified: Group 1 (markedly improved pinpoint accuracy), Group 2
(improved pinpoint accuracy), and Group 3 (reduced pinpoint accuracy). Group 1
had a high masseter resting tone, the masseter activity was low in MVC (maximum
voluntary clench) and increased in BOC (maximum bite on cotton rolls; p<
0.04). This indicates a masseter weakness, which would be compensated by a
mouthguard. In Group 2, the masseter activity in MVC was high-normal with an
imbalance which was improved in BOC (p< 0.01), indicating a possible
mouthguard benefit. In Group 3, MVC and BOC were in a high-normal range and
showed no relevant deficits. In these subjects the mouthguard had adverse
effects. Overall, subjects with masticatory deficits had a benefit from the
mouthguard in pinpoint accuracy. Positive or negative mouthguard responders may
be detectible from electromyographic tests.
Keywords
volleyball - mouthguard - pinpoint accuracy - body stabilization - EMG
