Oro‐facial activities in sleep bruxism patients and in normal subjects: a controlled polygraphic and audio–video study

Abstract

To our knowledge, the large spectrum of sleep motor activities (SMA) present in the head and neck region has not yet been systematically estimated in normal and sleep bruxism (SB) subjects. We hypothesized that in the absence of audio-video signal recordings, normal and SB subjects would present a high level of SMA that might confound the scoring specificity of SB. A retrospective analysis of several SMA, including oro-facial activities (OFA) and rhythmic masticatory muscle activities (RMMA), was made from polygraphic and audio-video recordings of 21 normal subjects and 25 SB patients. Sleep motor activities were scored, blind to subject status, from the second night of sleep recordings. Discrimination of OFA included the following types of activities: lip sucking, head movements, chewing-like movements, swallowing, head rubbing and scratching, eye opening and blinking. These were differentiated from RMMA and tooth grinding. The frequency of SMA per hour of sleep was lower in normal subjects in comparison with SB patients (P < 0.001). Up to 85% of all SMA in normal subjects were related to OFA while 30% of SMA in SB patients were related to OFA scoring (P < 0.001). The frequency of RMMA was seven times higher in SB patients than in normal subjects (P < 0.001). Several SMA can be observed in normal and SB subjects. In the absence of audio-video signal recordings, the discrimination of various types of OFA is difficult to achieve and may lead to erroneous estimation of SB-related activities.

Effects of Botulinum Toxin on Jaw Motor Events during Sleep in Sleep Bruxism Patients: A Polysomnographic Evaluation

“…28,29 On the other hand, BoNT-A prevents synaptic transmissions at the neuromuscular junctions, which results in a decrease of compound muscle action potentials. 27 Thus, the injections of BoNT-A on jaw-closing muscles failed to the prevent the genesis of RMMA episodes and OFAs during sleep. But, this study demonstrated the reducing effects of BoNT-A on the intensity of muscle contractions during sleep: the peak amplitude of EMG bursts during RMMA episodes decreased in the muscles with BoNT-A injection, i.e., masseter in group A and the masseter and temporalis muscles in group B. MA, masseter muscle; TE, temporalis muscle; MVC, maximal voluntary clenching; RMMA, rhythmic masticatory muscle activity.…”

“…In addition to these episodes, OFAs including lip sucking, head movement, chewing-like activity, swallowing, and eye opening were scored using audiovideo. 27 The number of OFAs per hour of sleep was calculated.…”

“…In addition to these episodes, OFAs including lip sucking, head movement, chewing-like activity, swallowing, and eye opening were scored using audiovideo. 27 The number of OFAs per hour of sleep was calculated.In addition to the above counts, the peak amplitude of EMG burst of the masseter and temporalis muscles during RMMA episodes were measured by ruler on the screen and maximum peak value was determined for each episode. …”

Weak association between sleep bruxism and obstructive sleep apnea. A sleep laboratory study

“…The presence of other movements that were not specific to SB could provide an alternative explanation [9,[12][13]. SB may have co-occurred with periodic limb movements in a subgroup of individuals [27].…”

“…In fact, recording and scoring of jaw muscle activity during sleep revealed that various types of muscle activity are not specific to SB events. These include myoclonic contraction, swallowing, sighing, and idiopathic or natural jaw muscle activity [12][13]. To assess the specificity of the putative association between OSAH and SB, it is critical to perform a discriminant analysis to distinguish typical RMMA in SB from other types of orofacial motor activity using polysomnography and audio-video recording (PSG-AV).…”