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Smartphone-assisted monitoring of masticatory muscle activity in freely moving individuals



To test a smartphone-assisted wireless device for assessing electromyographic (EMG) activity of the masseter muscle in freely moving individuals undertaking routine activities.

Materials and Methods

EMG activity was detected unilaterally from the masseter muscle in 12 volunteers using surface electrodes connected to both a smartphone-assisted wireless EMG device and a fixed-wired EMG equipment (reference standard). After performing a series of standardized tasks in the laboratory, participants wore the wireless device for 8 h while performing their normal routine.


The wireless device reliably detected masseter muscle contraction episodes under both laboratory and natural environment conditions. The intraclass correlation coefficients for the muscle contraction episode amplitude and duration detected by the wireless and the wired equipment ranged from 0.94–1.00 to 0.82–1.00, respectively. Most masseter contraction episodes during normal routine were of low amplitude (< 10% MVC) and short duration (< 10 s), with no significant differences between sexes or facial side.


Within the limitations of the study, smartphone-assisted monitoring of the jaw muscles represents a promising tool to investigate oral behavior patterns in free moving individuals.

Clinical relevance

Smartphone-assisted monitoring of masticatory muscle activity may enable possible associations between excessive muscle activity, bruxism, dysfunction, and pain to be investigated, and managed via biofeedback.

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We would like to thank engineers Max Farr, Max Allen, Kuang Ma, and Edwin Neiman from Kamahi Electronics, Dunedin for their support with the development and testing of the early prototypes of the wireless device. We also like to thank the team from AD Instruments (Dunedin, NZ) for providing the equipment for the research tests, Hamza Bennani for software support and students from the University of Otago for volunteering to participate in the research.


The development of the device was supported by research grants from the Lottery Health Research Grant, New Zealand Dental Association, and internal funding from the Discipline of Orthodontics at the University of Otago. This study was supported with funding from the New Zealand Dental Association and Pain@Otago research grants.

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Corresponding author

Correspondence to Mauro Farella.

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The authors declare that they have no conflict of interest.

Ethical approval

All procedures performed in the human participants were in accordance with the ethical standards of the institution and approval was obtained (H16/125).

Informed consent

Informed consent was obtained from all individual participants included in the study.

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Prasad, S., Paulin, M., Cannon, R.D. et al. Smartphone-assisted monitoring of masticatory muscle activity in freely moving individuals. Clin Oral Invest 23, 3601–3611 (2019).

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  • Bruxism
  • Electromyography
  • Masticatory muscles
  • Smartphone
  • Tooth clenching
  • Wireless body area network
  • Wearable electronic device