Sleep bruxism, an autonomic self-regulating response by triggering the trigeminal cardiac reflex.

Sleep bruxism, an intensified manifestation of rhythmic masticatory muscle activity, characterized by tooth grinding or clenching during sleep, lacks a definitive physiological purpose. This paper posits that physiologically, sleep bruxism is an autonomic self-regulatory response to nighttime occurrences of tachycardia stemming from the brain experiencing microarousals during sleep. Sleep bruxism by triggering the trigeminal cardiac reflex leads to bradycardia. Rhythmic masticatory muscle activity-sleep bruxism, thereby, serves to slow the heart rate when brain microarousals cause tachycardia.

Sleep disorders in childhood: a review.

Several studies in the last ten years have been directed towards a better understanding of sleep disorders in childhood. Defining sleep disorders in this age is difficult in dependence of relevant differences in sleep patterns at subsequent developmental stages. In new-borns total sleep time is fairly equal during night and day. Normally, day-time sleep gradually decreases over the first three years of life, such that night-time sleep progressively increases till the age of four, and similar to adult sleep-time by adolescence. The most frequent sleep disorders observed in childhood are parasomnias, that, thought to be a CNS sign of immaturity, tend to be quite predictable, recurring in the same families and not even influenced by environmental stimuli. These disorders included: a) arousal disorders, that generally emerge from delta sleep or relate to arousals occurring during NREM sleep, very common in childhood and fairly common in adulthood either; b) somnambulism and somniloquy, that have many common characteristics: first of all, they have the potential to generate a great sense of discomfort and fear in parents watching a child who suddenly sits up in bed eyes-opened but 'unseeing'; c) nocturnal enuresis, that is substantially not a problem of depth of sleep, despite many parents believe. Although narcolepsy is more common in adolescence, many studies have demonstrated that narcoleptic symptoms may begin in childhood. Narcoleptic symptoms in children are similar in their appearance to those predominant in adults, but their expression may be different because of CNS maturational factors. Historical descriptions of the OSAS evidenced since the beginning the importance of neurobehavioral complications associated with the cessation of airflow at the nose and mouth accompanied by respiratory effort, deriving from upper airway obstruction which occurs during sleep.

Sleep bruxism: a comprehensive overview for the dental clinician interested in sleep medicine.

Sleep bruxism (SB) is a common sleep-related motor disorder characterized by tooth grinding and clenching. SB diagnosis is made on history of tooth grinding and confirmed by polysomnographic recording of electromyographic (EMG) episodes in the masseter and temporalis muscles. The typical EMG activity pattern in patients with SB is known as rhythmic masticatory muscle activity (RMMA). The authors observed that most RMMA episodes occur in association with sleep arousal and are preceded by physiologic activation of the central nervous and sympathetic cardiac systems. This article provides a comprehensive review of the cause, pathophysiology, assessment, and management of SB.

Sleep bruxism is associated to micro-arousals and an increase in cardiac sympathetic activity.

Sleep bruxism (SB) subjects show a higher incidence of rhythmic masticatory muscle activity (RMMA) than control subjects. RMMA is associated with sleep micro-arousals. This study aims to: (i) assess RMMA/SB episodes in relation to sleep cycles; (ii) establish if RMMA/SB and micro-arousals occur in relation to the slow wave activity (SWA) dynamics; (iii) analyze the association between RMMA/SB and autonomic cardiac activity across sleep cycles. Two nights of polygraphic recordings were made in three study groups (20 subjects each): moderate to high SB, low SB and control. RMMA episodes were considered to occur in clusters when several groups of RMMA or non-specific oromotor episodes were separated by less than 100 s. Correlations between sleep, RMMA/SB index and heart rate variability variables were assessed for the first four sleep cycles of each study group. Statistical analyses were done with SYSTAT and SPSS. It was observed that 75.8% of all RMMA/SB episodes occurred in clusters. Micro-arousal and SB indexes were highest during sleep cycles 2 and 3 (P < 0.001). Within each cycle, micro-arousal and RMMA/SB indexes showed an increase before each REM sleep (P