Background: The gold standard for diagnosing sleep bruxism (SB) and obstructive sleep apnea (OSA) is polysomnography (PSG). However, a final hypermotor muscle activity often occurs after apnea episodes, which can confuse the diagnosis of SB when using portable electromyography (EMG) devices. This study aimed to compare the number of SB episodes obtained from PSG with manual analysis by a sleep expert, and from a manual and automatic analysis of an EMG and electrocardiography (EKG) device, in a population with suspected OSA. Methods: Twenty-two subjects underwent a polysomnographic study with simultaneous recording with the EMG-EKG device. SB episodes and SB index measured with both tools and analyzed manually and automatically were compared. Masticatory muscle activity was scored according to published criteria. Patients were segmented by severity of OSA (mild, moderate, severe) following the American Academy of Sleep Medicine (AASM) criteria. ANOVA and the Bland–Altman plot were used to quantify the agreement between both methods. The concordance was calculated through the intraclass correlation coefficient (ICC). Results: On average, the total events of SB per night in the PSG study were (8.41 ± 0.85), lower than the one obtained with EMG-EKG manual (14.64 ± 0.76) and automatic (22.68 ± 16.02) analysis. The mean number of SB episodes decreases from the non-OSA group to the OSA group with both PSG (5.93 ± 8.64) and EMG-EKG analyses (automatic = 22.47 ± 18.07, manual = 13.93 ± 11.08). However, this decrease was minor in proportion compared to the automatic EMG-EKG analysis mode (from 23.14 to 22.47). The ICC based on the number of SB episodes in the segmented sample by severity degree of OSA along the three tools shows a moderate correlation in the non-OSA (0.61) and mild OSA (0.53) groups. However, it is poorly correlated in the moderate (0.24) and severe (0.23) OSA groups: the EMG-EKG automatic analysis measures 14.27 units more than PSG. The results of the manual EMG-EKG analysis improved this correlation but are not good enough. Conclusions: The results obtained in the PSG manual analysis and those obtained by the EMG-EKG device with automatic and manual analysis for the diagnosis of SB are acceptable but only in patients without OSA or with mild OSA. In patients with moderate or severe OSA, SB diagnosis with portable electromyography devices can be confused due to apneas, and further study is needed to investigate this.

Background: The therapeutic approach to myofascial TMD should focus on pain relief and rehabilitation of function.Objective: This study investigated whether pressure release technique (PRT) is effective for reducing pain in people with chronic myofascial temporomandibular disorders (TMD).Methods: A single‐blinded randomised parallel‐group trial, with 3 months follow‐up was conducted. A total of 72 patients were randomly allocated to receive PRT or sham PRT. Primary outcome was pain assessed with a visual analogue scale (VAS). Secondary outcomes included pressure pain thresholds (PPTs), range of opening of the mouth (ROM), Neck Disability Index (NDI), Pain Catastrophizing Scale (PCS), Tampa Scale for Kinesiophobia (TSK‐11), State–Trait Anxiety Index (STAI) and State–Trait Depression Index (ST‐DEP). All parameters were assessed at baseline, at the end of the treatment and at 3 months follow‐up. Statistical analysis was performed by ANOVA.Results: There were significant main effects of time, group and interaction between time and group (F ≥ 21.92; p < .001) on VAS pain. Post hoc tests showed a significant reduction in VAS pain scores in the PRT group (≥31.9%; p < .001). Effect sizes were moderate in the PRT group at all follow‐up periods (≥1.25 Cohen's d). Also, there were significant effects of time in secondary outcomes (F ≥ 9.65; p < .001), and there were also interactions between time and group (F ≥ 3.82; p < .002) with better effects in the PRT group.Conclusions: The inclusion of PRT to conventional management with occlusal splints and self‐care management appears to be effective to improve self‐reported levels of pain in patients with chronic myofascial TMD pain. Retrospectively registered (ClinicalTrials.gov: NCT03619889).

Background: Many studies have revealed high comorbidity and a clear association between temporomandibular disorders (TMD) and migraine. Furthermore, evidence points out that common psychological and behavioral factors might be related to the observed TMD and migraine association. However, this association and the underlying psychological factors are poorly understood. Objective: The main goal of this study was to describe the psychological and behavioral factors involved in TMD myalgia and migraine. Methods: A sample of 142 participants were recruited to form 4 groups: migraine patients (ICHD-III criteria), painful-TMD patients (Myalgia DC/TMD criteria), patients suffering from both pathologies according to the same criteria, and control patients. After a dental and neurological examination, the patients filled several psychological questionnaires validated for the Spanish population to assess anxiety (STAI), depression (DEP), stress coping (CRI), and somatic, anxiety, and depression symptoms (BSI-18). Results: The TMD myalgia patients, in general, showed a state of elevated anxiety, somatization, and reduced coping strategies, while the patients with migraine presented greater anxiety symptoms, depression (dysthymia trait and state), and somatization. Conclusions: According to the data of the present study, situational anxiety (transient emotional state), together with the lack of coping strategies, could be more associated with TMD myalgia, while anxiety, as a more stable and long-lasting emotional state, together with depression, might be more related to migraine. Further longitudinal studies are needed to unravel whether these differentiated profiles are a consequence or possible risk factors for migraine and TMD.

The purpose of this study was to analyze the influence of pain and no pain expectation on pupil diameter and the cognitive assessment of pain using pupillometry and the visual analog scale (VAS). This was an experimental cross-sectional study in which painful stimulation of the muscle masseter was produced by palpation with an algometer in a sample of 30 healthy participants. Before the painful stimulation, pain expectation and no pain expectation situations were induced by employing instructional videos. Cognitive and physiological pain responses were measured by the VAS and by pupillometry. Visual analog scale score was assessed at the end of each experimental condition, and pupillometry measurements were recorded at different moments of the experimental process (events). The pain score and larger pupil diameter for all events (except, as expected, for the initial baseline), were statistically significant for the pain expectation condition compared with the no pain expectation. Within the conditions of this study, pain expectation modulated both cognitive assessment of pain (VAS) and pupil diameter. These findings suggest that pupil diameter may be a useful and complementary tool with the VAS for pain assessment. Furthermore, the findings support models postulating that emotion and cognition are important aspects involved in pain perception, which is in line with the recent International Association for the Study of Pain definition of pain.

Background: The gold standard for the diagnosis of sleep bruxism (SB) and obstructive sleep apnea (OSA) is Polysmnography (PSG). At the end of the apnea episodes there is frequently a final hy-permotor muscle activity that could act as a confusion factor in the diagnosis of SB with the elec-tromyography portable devices. The aim of this study was to compare the concordance on the number of episodes of SB in a population with OSA, between the diagnosis obtained by PSG, an-alyzed manually by a neurophysiologist and that obtained manually and automatically by a portable electromyography (EMG) and electrocardiography (EKG) device. Methods: Twenty-three subjects underwent one night of polysomnographic study with simulta-neous recording with the EMG-EKG device. The variables referring to the number of episodes and the SB index measured with both tools and analyzed in the manual and automatic modes were compared. Masticatory muscle activity was scored according to published criteria. The sample was segmented by severity of OSA according to AASM criteria. ANOVA, correlations, and the Bland–Altman plot were used to quantify the agreement between both methods. The concordance was calculated through the ICC. Results: The total events of SB per night in the PSG study were on average (8.17), lower than the one obtained with EMG-EKG manual analysis (14.13) and automatic (29.26). Both the SB PSG and Manual EMG-EKG episodes decrease from non-OSA (PSG = 16 ± 13,55, EMG-EKG = 16,83 ±11,58) to severe OSA (PSG = 3,14 ± 4,26, EMG-EKG = 9,86 ± 8,09). However, in the case of automatic EMG-EKG mode: the number of SB episodes in severe OSA doubled (41,23 ± 12,50) with respect to non OSA (24,50 ± 12,19). On average: the EMG-EKG device Automatic analysis measures 21.08 units more than PSG. The results with the manual EMG-EKG analysis improved. Conclusion: There is no concordance between the results obtained in the PSG neurophysiologic analysis and those obtained by means of the EMG-EKG device automatic and manual analysis for the diagnosis of SB in a population mostly with OSA. The OSA could act as a confusion factor in the diagnosis of SB with the electromyography portable devices, but further study is needed.