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Influence of mouth guards on autonomic nervous system activities: A quantitative study of pupillary flash responses
Author(s) -
Ishida Junichi,
Wada Yoshiro,
Imai Yuichiro,
Hirata Yutaka,
Yamashita Masayuki,
Kirita Tadaaki
Publication year - 2012
Publication title -
oral science international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.256
H-Index - 13
eISSN - 1881-4204
pISSN - 1348-8643
DOI - 10.1016/s1348-8643(12)00026-2
Subject(s) - autonomic nervous system , medicine , sensation , heart rate variability , parasympathetic nervous system , sympathetic nervous system , audiology , pupil , nervous system , anesthesia , psychology , physical medicine and rehabilitation , heart rate , neuroscience , psychiatry , blood pressure
Background: Recently, it has been reported that mouth guards (MGs), which reduce the incidence and severity of traumatic oral injuries in contact sports, may actually affect sports performance. We have observed that a majority of subjects showed improved dynamic visual acuity during head rotation when using a MG, but subjects who were unwilling to use a MG showed the opposite effect. Thus, we hypothesized that unpleasant sensations due to MGs may decrease sports performance. Methods: In this study, we measured autonomic nervous system activity to evaluate unpleasant sensations objectively and quantitatively by measuring the pupillary flash response (PFR) and heart rate variability (HRV), before, during, and after wearing 3‐ and 5‐mm‐thick custom‐made MGs in 10 healthy subjects. Results: It was found that the 5‐mm MG had a higher incidence of unpleasant sensations (50% of subjects) than did the 3‐mm MG (10%). PFR (not HRV) analysis showed that both sympathetic and parasympathetic nervous system activities increased in subjects with unpleasant sensations. Conclusions: We suggest that the unpleasant sensation induced this unusual autonomic nervous system response, which could not be detected by traditional methods such as HRV analysis. By using PFR analysis, it is possible to make MGs without unpleasant sensations for better sports performance.