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Published on: September 21, 2017
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Effect of jaw clenching on head acceleration during a predictable load impact
Kazuki Sako1, Yuto Tanaka2, Yosuke Tomita3
1Department of Fixed Prosthodontics and Occlusion, Osaka Dental University, Hirakata, Japan.
Journal of Oral Rehabilitation
|September 9, 2021
Summary
Jaw clenching does not reduce head acceleration during impacts. A relaxed jaw position, with jaw opener and closer muscles co-contracting without tooth contact, may offer inherent safety benefits for reducing head acceleration.
Area of Science:
- Biomechanics
- Sports Medicine
- Neuromuscular Control
Background:
- Jaw clenching is hypothesized to mitigate head acceleration during impacts in sports.
- Understanding this mechanism is crucial for injury prevention strategies.
Purpose of the Study:
- To investigate the effect of voluntary jaw clenching on head acceleration during predictable body impacts.
- To compare the protective effects of jaw clenching versus a naturally relaxed jaw position.
Main Methods:
- Seven healthy participants underwent predictable load impacts, with and without instructed jaw clenching.
- Electromyography of masseter (MA) and digastricus (DIG) muscles, occlusal pressure, and head acceleration were recorded.
Main Results:
- Participants naturally adopted a relaxed jaw position without occlusal contact during impacts when not instructed to clench.
- Instructed jaw clenching did not significantly alter head acceleration or jaw opener muscle activity compared to the relaxed state.
Conclusions:
- A relaxed jaw posture, involving co-contraction of jaw muscles without occlusal contact, may intrinsically reduce head acceleration.
- Jaw clenching offers no additional benefit in reducing head acceleration beyond this natural protective mechanism.
- Digastricus (DIG) muscle activation appears critical for head acceleration reduction, irrespective of masseter (MA) muscle activity during impacts.
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