Multiple sleep bruxism data collected using a self-contained EMG detector/analyzer system in asymptomatic healthy subjects
- 275 Downloads
Small, self-contained electromyographic (EMG) detector/analyzer (D/A) devices have become available for the detection of jaw muscle activity events above threshold. These devices claim to be less intrusive to the subjects sleep so it is less prone to induce disturbed sleep. The objective of this study was to evaluate for night-to-night variability and examine for a systematic alteration on the first night in EMG levels.
Ten asymptomatic healthy volunteers (mean age, 26.8 ± 3.78) were recorded for six sequential nights in their home environment using EMG D/A system. The device yields a nightly EMG level above threshold score on a 0–4 level. Because the data are categorical and nonparametric, the data of the ten subjects across six nights were submitted to a Friedman repeated measures ANOVA. The significant level was set as alpha equal to 0.05.
The median and mode values of the subjects were tabulated and analyzed and we did not find a significant difference in EMG D/A level across the six nights (p = 0.287, Kendall's coefficient of concordance = 0.124, Friedman two-way repeated measures ANOVA). The data did show clear and substantial night-to-night variability.
Substantial night-to-night variability in masseter EMG activity levels was clearly observed in our subjects. There was no evidence of a suppressed or elevated first-night effect-like variability on masseter muscle EMG level seen in these subjects using a small portable self-contained EMG detector/analyzer. These data suggest that recordings should be at least 5–6-nights duration to establish a reasonable measure of an individual's average nightly masseter EMG level.
KeywordsSleep bruxism Portable device Electromyography First-night effect-like variability Validation study Clinical assessment
This study was also supported in part by Grant-In-Aids (#16591949, #18592122, and #20592265) for Scientific Research from the Ministry of Education, Science and Culture, Japan. The authors declare that they have no conflict of interest.
- 19.Rugh JD, Harlan J (1988) Nocturnal bruxism and temporomandibular disorders. In: Jankovic J, Tolosa E (eds) Advances in neurology. Raven, New York, pp 329–341Google Scholar
- 20.Cosmanescu A, Miller B, Magno T, Ahmed A, Kremenic I (2006) Design and implementation of a wireless (Bluetooth) four channel bio-instrumentation amplifier and digital data acquisition device with user-selectable gain, frequency, and driven reference. Conf Proc IEEE Eng Med Biol Soc 1:2053–2056PubMedGoogle Scholar
- 21.Yamaguchi T, Mikami S, Okada K (2007) Validity of a newly developed ultraminiature cordless EMG measurement system. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 104:22–27Google Scholar