Frequency of Sleep Bruxism Behaviors in Healthy Young Adults over a Four-Night Recording Span in the Home Environment

Daniele Manfredini,Marzia Segù,Luca Lombardo,Anna Colonna

doi:10.3390/app11010195

Daniele Manfredini, Marzia Segù + Show 2 more

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https://doi.org/10.3390/app11010195

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Abstract

Objectives: This study aimed to assess frequency and multiple-night variability of sleep bruxism (SB) as well as sleep-time masticatory muscle activities (sMMA) in the home environment in healthy young adults using a portable device that provides electrocardiographic (ECG) and surface electromyographic (EMG) recordings from the masticatory muscles. Methods: The study was performed on 27 subjects (11 males, 16 females; mean age 28.3 ± 1.7 years) selected from a sample of healthy young students. Evaluation was carried out for four nights to record data on masticatory muscle activities using a compact portable device that previously showed an excellent agreement with polysomnography (PSG) for the detection of SB events. The number of SB episodes per sleep hour (bruxism index), and the number of tonic, phasic and mixed sMMA events per hour were assessed. A descriptive evaluation of the frequency of each condition was performed on all individuals, and gender comparison was investigated. Results: Mean sleep duration over the four recording nights was 7 ± 1.3 h. The average SB index was 3.6 ± 1.2. Most of the sMMA were tonic (49.9%) and phasic (44.1%). An ANOVA test showed the absence of significant differences between the four nights. No significant gender differences were detected for the SB index, phasic or tonic contractions; conversely, gender differences were detected for mixed sMMA events (p < 0.05). Conclusion: This investigation supports the concept that sMMA events are quite frequent in healthy adults. Differences over the four-night recording span were not significant. These data could be compared to subjects with underlying conditions that may lead to an additive bruxism activity and possible clinical consequences.

Highlights

Bruxism is an oromandibular condition characterized by different activities of the jaw muscles and two distinct circadian manifestations, viz., awake bruxism (AB) and sleep bruxism (SB) [1]
The peculiar study populations recruited for research purposes and the focus on the number of SB events, instead of the full spectrum of sleep-time masticatory muscle activities (sMMA) activities, emerged as shortcomings to address for further refining of the SB epidemiology [13]
Within the limits of the present study, which was designed to evaluate sleep bruxism behaviors in a sample of healthy young adults using a portable EMG/ECG device, findings suggest that sMMA events associated with heart-rate increase are quite frequent

Summary

Introduction

Bruxism is an oromandibular condition characterized by different activities of the jaw muscles (i.e., grinding or clenching of the teeth and/or thrusting or bracing of the mandible) and two distinct circadian manifestations, viz., awake bruxism (AB) and sleep bruxism (SB) [1]. A panel of experts proposed two distinct definitions for awake and for sleep bruxism; the latter is defined as a masticatory muscle activity during sleep that is characterized as rhythmic (phasic) or non-rhythmic (tonic) [1]. This would not be considered a disorder per se in otherwise healthy individuals, but it might be viewed as a protective and/or a risk factor for some clinical consequences [1,2,3]. A large-scale polysomnography (PSG)-based epidemiological study underlines that the prevalence of SB was 7.4% when PSG was used as an exclusive criterion for diagnosis, whereas it was 5.5% when screened by questionnaires and confirmed by PSG [9]

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