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Muscular activity during isometric incisal biting.
Urbano Santana-Mora1, Arturo Martínez-Ínsua1, Urbano Santana-Penín1
1Department of Stomatology, Faculty of Medicine and Odontology, University of Santiago de Compostela, Santiago de Compostela, La Coruña, Spain.
Journal of Biomechanics
|December 3, 2014
Summary
This study measured temporomandibular joint (TMJ) loading during biting. Masseter muscles drive incisal loads, with excessive biting potentially causing harmful TMJ stress.
Area of Science:
- Biomechanical Engineering
- Dental Mechanics
- Neuroscience
Background:
- Temporomandibular joint (TMJ) loading during incisal tasks is crucial for understanding jaw function.
- Assessing the correlation between muscle activity and joint forces provides insight into physiological and pathological loading.
Purpose of the Study:
- To estimate TMJ loading during incisal tasks.
- To correlate surface electromyography (sEMG) of jaw muscles with measured incisal loads.
Main Methods:
- Utilized a custom load-cell device to record incisal loads in 23 healthy volunteers.
- Simultaneously recorded sEMG of masseter and temporalis muscles during various biting efforts.
- Normalized sEMG data using maximal clenching activity.
Main Results:
- Masseter muscles primarily generated incisal loads, showing a positive correlation with mean effort.
- No significant differences in sEMG activity were found between the four jaw muscles during submaximal clenching.
- Normalized mean sEMG activity was 49.99% during submaximal voluntary incisal loading and 27.17% during mean effort.
Conclusions:
- Incisal loading necessitates masseter muscle activity, which correlates positively with effective loads during mean, but not submaximal, effort.
- Masseter muscles are dominant over temporalis muscles during submaximal incisal biting.
- While mean incisal load appears physiological, excessive or chronic incisal loading may lead to detrimental TMJ loads.
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