University of Oulu

Miettinen, T., Myllymaa, K., Muraja-Murro, A. et al. Polysomnographic scoring of sleep bruxism events is accurate even in the absence of video recording but unreliable with EMG-only setups. Sleep Breath 24, 893–904 (2020).

Polysomnographic scoring of sleep bruxism events is accurate even in the absence of video recording but unreliable with EMG-only setups

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Author: Miettinen, Tomi1,2,3; Myllymaa, Katja1,3; Muraja-Murro, Anu3;
Organizations: 1Department of Applied Physics, University of Eastern Finland, PO Box 1627, FI-70211, Kuopio, Finland
2Institute of Dentistry, University of Eastern Finland, Kuopio, Finland
3Department of Clinical Neurophysiology, Diagnostic Imaging Center, Kuopio University Hospital, Kuopio, Finland
4Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
5Department of Oral and Maxillofacial Diseases, Kuopio University Hospital, Kuopio, Finland
6Oral and Maxillofacial Department, Medical Research Center Oulu, Oulu University Hospital, Oulu, Finland
7Research Unit of Oral Health Sciences, Faculty of Medicine, University of Oulu, Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 1.4 MB)
Persistent link:
Language: English
Published: Springer Nature, 2019
Publish Date: 2020-01-16


Purpose: To determine the accuracy of scoring masticatory muscle activity (MMA) events in seven different polysomnography (PSG) setups.

Methods: Nineteen volunteers (13 females, 6 males, age 31.1 ± 12.9 years, 12 self-proclaimed bruxers) attended one-night PSG recording, supplemented with audio, video, and a separate frontal electroencephalography electrode set (FES). The same examiner scored the MMA events with seven different setups, with varying number of channels available: (1) one, (2) two, and (3) four EMG channels, (4) PSG without audio or video (PSG-N), (5) home PSG with FES and audio (FES-A), (6) PSG with audio (PSG-A), and (7) PSG with audio and video (PSG-AV). A subset (n = 10) of recordings was scored twice to determine intra-scorer reliability. MMA indices and accuracy of scoring the events in different setups were compared against PSG-AV.

Results: The intra-class correlation coefficient (ICC) between PSG-AV and PSG-A was high (0.940, p < 0.001) as well as for FES-A (0.927, p < 0.001), whereas for PSG-N, it was lower (0.835, p < 0.001); for setups with only EMG channels, coefficients were very low (ICC < 0.100 for all). Intra-examiner reliability was high (ICC > 0.939 for all setups), with the exception of PSG-N (ICC = 0.764, p = 0.002). When comparing against the MMA events scored in PSG-AV, the sensitivity of MMA event recognition for PSG-A was 78.5% and specificity 95.5%, which were substantially higher than sensitivity (52.0%) and specificity (87.2%) of PSG-N.

Conclusions: MMA event scoring accuracy with PSG-A or FES-A is almost comparable to PSG-AV. Since precise event recognition is essential for accurate MMA scoring, it is evident that one cannot rely exclusively on EMG.

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Series: Sleep and breathing
ISSN: 1520-9512
ISSN-E: 1522-1709
ISSN-L: 1520-9512
Volume: 24
Pages: 893 - 904
DOI: 10.1007/s11325-019-01915-2
Type of Publication: A1 Journal article – refereed
Field of Science: 313 Dentistry
Funding: Open access funding provided by University of Eastern Finland (UEF) including Kuopio University Hospital. This work was financially supported by The Finnish Funding Agency for Technology and Innovation (project 40047/14), Academy of Finland (project 313697, User-Centered Health Technology and Digital Health Services), and by grants from the Research Committee of Kuopio University Hospital Catchment Area for the State Research Funding (projects 5041739, 5041761, 5041764, and 5041770), Research Foundation for Pulmonary Diseases, and Runar Bäckström Foundation. T. Miettinen has been supported by grants from Instrumentarium Science Foundation and North Savo Regional Fund of Finnish Cultural Foundation.
Academy of Finland Grant Number: 313697
Detailed Information: 313697 (Academy of Finland Funding decision)
Copyright information: © The Author(s) 2019. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.