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

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.

Effect of masseter muscle activity during wakefulness and sleep on tooth wear

“…However, a study comparing rhythmic masticatory muscle activity (RMMA) during the first night with that of the second night using polysomnography showed no first-night effect on the severity of RMMA frequency [38]. Additionally, the first night effect was not observed in a study that evaluated the masseter electromyographic activity over 4 consecutive nights using a portable device [39]. Furthermore, Saito et al investigated the minimum measurement time of masseter electromyographic activity needed to assess awake bruxism during wakefulness and concluded that more than to 2.5-3.0 h were necessary for accurately measuring muscle activity [14].…”

Associations between Bruxism, Stress, and Manifestations of Temporomandibular Disorder in Young Students

“…Data collection can be improved by an instrumental assessment method, the momentary ecological assessment (EMA), which provides multiple reports over an observation period [44] and allows the collection of data on the association between bruxism and other manifestations [45]. A more relevant assessment of the muscular activity, especially in the case of SB, may be accomplished by polysomnography (electromyography-EMG, electroencephalography-EEG, electrooculography-ECG), completed with audio and/or video recordings [24,46]. Castroflorio et al monitored the cardiac, respiratory and brain activity, showing that there are brief sudden modifications of these parameters before an SB event.…”

State of the Art in Comorbidities and Complications Associated with Sleep-Related Breathing Disorders

“…They showed that during sleep time, Masticatory Muscles activities (sMMA) events associated with heart-rate increase are quite frequent. The average SB index over the four nights that were recorded was 3.6 +/− 1.2 [15].…”