TITLE:
Effect of Wearing an Oral Appliance on Range of Motion of Spine during Trunk Flexion
AUTHORS:
Mutsumi Takahashi, Yogetsu Bando, Katsuhiko Kitaoka, Keisuke Hata
KEYWORDS:
Spinal Alignment, Spinal Range of Motion, Clenching, Oral Appliance, Mouthguard, Trunk Flexion
JOURNAL NAME:
Advances in Physical Education,
Vol.13 No.4,
November
29,
2023
ABSTRACT: Purpose: The aim of this study was to clarify the effect of wearing an oral
appliance on the range of motion of the spine during trunk flexion in
elite-level athletes. Method: Participants were 15 elite-level female handball players (24.9 ± 2.0
years). A single-layer mouthguard was fabricated using a 2.0-mm-thick
thermoplastic sheet that all teeth were adjusted to make even contact upon
light clenching. Spinal curvature was measured in the static standing posture
and standing forward-bending posture by using a spinal shape analyzer. The evaluation indices were thoracic kyphosis angle
(TKA), lumbar lordosis angle (LLA),
sacral inclination angle (SSA), and spinal inclination angle (SIA).
Measurements were made under three conditions: mandibular resting position
(RP), clenching in the intercuspal position (ICP), and clenching while wearing
a mouthguard (MG). Differences in spinal curvature due to occlusal conditions
were compared using repeated measure analysis of variance. Results: LLA,
SSA, and SIA showed significant differences between RP and ICP, and between RP
and MG, with RP having the greatest range of motion. There was no significant
difference in any spinal alignment between ICP and MG. TKA was not
significantly affected by occlusal condition. Conclusion: This study was
clarified that lumbar lordosis angle, sacral inclination angle, and spinal
inclination angle during trunk flexion decreased with clenching, regardless of the presence or absence of an oral
appliance. Therefore, it was suggested
that clenching contributes to trunk stabilization and may affect flexibility.