OBJECTIVE: The mandibular advancement appliance (MAA) is now recognized as a first-line therapy option for mild to moderate obstructive sleep apnea syndrome (OSAS). The aim of this follow-up study was to re-assess the long-term efficacy of MAAs provided to patients in a previous comparative study. METHODS: Sixteen subjects had participated in a previous comparative study in which the efficacy and compliance of two MAAs (Klearway - K and Silencer - S) were compared in a randomized cross-over design. At the end of the previous comparative study, subjects selected the MAA they preferred. Nine chose the K and seven the S. Fifteen subjects were available for a follow-up interview and 14 (4 women and 10 men; mean±SEM: 51.9±1.7y.o.) agreed to participate in an overnight sleep recording at a hospital sleep laboratory from January to February 2009. The mean time lag between the end of the previous comparative study and the follow-up was 40.9±2.1months (range of 2.5-4.5years). Comparisons were made across the three polysomnographic evaluations (PSGE): baseline, the night with the appliance of their choice at the end of the previous comparative study, and the follow-up night. Subjects completed the Epworth sleepiness scale (ESS), the fatigue severity scale (FSS), and a quality of life questionnaire (FOSQ). RESULTS: At the follow-up, the respiratory disturbance index (RDI) remained significantly lower than baseline (p<0.001). Questionnaire responses revealed that ESS, FSS, and FOSQ remained improved at follow-up (p<0.02). Body mass index (BMI) increased slightly from baseline to follow-up (p<0.05). Diastolic and systolic blood pressure and cardiac rhythm decreased significantly from baseline to follow-up. CONCLUSIONS: The MAAs remained effective in improving RDI, sleepiness, blood pressure, cardiac rhythm, fatigue, sleep quality, and quality of life over a period of 2.5-4.5years. The rise in BMI is a concern that merits further examination.

Carra MC, Huynh N, Morton P, Rompré PH, Papadakis A, Remise C, Lavigne GJ. Prevalence and risk factors of sleep bruxism and wake-time tooth clenching in a 7- to 17-yr-old population. Eur J Oral Sci 2011; 119: 386-394. © 2011 Eur J Oral Sci Sleep-related bruxism (SB) and wake-time tooth clenching (TC) have been associated with temporomandibular disorders (TMDs), headache, and sleep and behavioral complaints. This study aimed to assess the prevalence and risk factors of these signs and symptoms in a 7- to 17-yr-old population (n = 604) seeking orthodontic treatment. Data were collected by questionnaire and by a clinical examination assessing craniofacial morphology and dental status. Sleep-related bruxism was reported by 15% of the population and TC was reported by 12.4%. The SB group (n = 58) was mainly composed of children (67.3% were ≤12 yr of age) and the TC group (n = 42) was mainly composed of adolescents (78.6% were ≥13 yr of age). The craniofacial morphology of over 60% of SB subjects was dental class II and 28.1% were a brachyfacial type. Compared with controls (n = 220), SB subjects were more at risk of experiencing jaw muscle fatigue [adjusted OR (AOR) = 10.5], headache (AOR = 4.3), and loud breathing during sleep (AOR = 3.1). Compared with controls, TC subjects reported more temporomandibular joint clicking (AOR = 5), jaw muscle fatigue (AOR = 13.5), and several sleep and behavioral complaints. Sleep- and wake-time parafunctions are frequently associated with signs and symptoms suggestive of TMDs, and with sleep and behavioral problems. Their clinical assessment during the planning of orthodontic treatment is recommended.

Most patients with chronic musculoskeletal pain report poor-quality sleep. The impact of chronic pain on sleep can be described as a vicious circle with mutual deleterious influences between pain and sleep-associated symptoms. It is difficult, however, to extract quantitative or consistent and specific sleep variables (eg, total sleep time, slow-wave sleep, sleep stage duration) that characterize the pain-related disruption of sleep. Comorbidity (eg, fatigue; depression; anxiety, sleep, movement, or breathing disorders) often confounds the reading and interpretation of sleep traces. Furthermore, many other methodologic issues complicate our ability to generalize findings (low external validity) to first-line medicine. Because sleep alterations in common musculoskeletal pain are neither specific nor pathognomonic, the aim is to provide a critical overview of the current understanding of pain and sleep interaction, discussing evidence-based and empiric knowledge that should be considered in further research and clinical applications.

Aims: To evaluate the influence of an oral appliance on morning headache and orofacial pain in subjects without reported sleep-disordered breathing (SDB). Methods: Twelve subjects aged 27.6 ± 2.1 (mean ± SE) years and suffering from frequent morning headache participated in this study. Each subject was individually fitted with a mandibular advancement appliance (MAA). The first two sleep laboratory polygraphic recording (SLPR) nights were for habituation (N1) and baseline (N2). Subjects then slept five nights without the MAA (period 1: P1), followed by eight nights with the MAA in neutral position (P2), ending with SLPR night 3 (N3). Subjects then slept five nights without the MAA (P3), followed by eight nights with the MAA in 50% advanced position (P4), ending with SLPR night 4 (N4). Finally, subjects slept 5 nights without the MAA (P5). Morning headache and orofacial pain intensity were assessed each morning with a 100-mm visual analog scale. Repeated measures ANOVAs and Friedman tests were used to evaluate treatment effects. Results: Compared to the baseline period (P1), the use of an MAA in both neutral and advanced position was associated with a ⋝ 70% reduction in morning headache and ⋝ 42% reduction in orofacial pain intensity (P ⋜ .001). During the washout periods (P3 and P5), morning headache and orofacial pain intensity returned to close to baseline levels. Compared to N2, both MAA positions significantly reduced (P <.05) rhythmic masticatory muscle activity (RMMA). Conclusion: Short-term use of an MAA is associated with a significant reduction in morning headache and orofacial pain intensity. Part of this reduction may be linked to the concomitant reduction in RMMA. J OROFAC PAIN 2011;25:240-249.

Clinicians and investigators need a simple and reliable recording device to diagnose or monitor sleep bruxism (SB). The aim of this study was to compare recordings made with an ambulatory electromyographic telemetry recorder (TEL-EMG) with those made with standard sleep laboratory polysomnography with synchronised audio-visual recording (PSG-AV). Eight volunteer subjects without current history of tooth grinding spent one night in a sleep laboratory. Simultaneous bilateral masseter EMG recordings were made with a TEL-EMG and standard PSG. All types of oromotor activity and rhythmic masseter muscle activity (RMMA), typical of SB, were independently scored by two individuals. Correlation and intra-class coefficient (ICC) were estimated for scores on each system. The TEL-EMG was highly sensitive to detect RMMA (0·988), but with low positive predictive value (0·231) because of a high rate of oromotor activity detection (e.g. swallowing and scratching). Almost 72% of false-positive oromotor activity scored with the TEL-EMG occurred during the transient wake period of sleep. A non-significant correlation between recording systems was found (r = 0·49). Because of the high frequency of wake periods during sleep, ICC was low (0·47), and the removal of the influence of wake periods improved the detection reliability of the TEL-EMG (ICC = 0·88). The TEL-EMG is sensitive to detect RMMA in normal subjects. However, it obtained a high rate of false-positive detections because of the presence of frequent oromotor activities and transient wake periods of sleep. New algorithms are needed to improve the validity of TEL-EMG recordings.

Rhythmic masticatory muscle activity (RMMA) is the characteristic electromyographic pattern of sleep bruxism (SB), a sleep-related motor disorder associated with sleep arousal. Sleep arousals are generally organised in a clustered mode known as the cyclic alternating pattern (CAP). CAP is the expression of sleep instability between sleep maintaining processes (phase A1) and stronger arousal processes (phases A2 and A3). This study aimed to investigate the role of sleep instability on RMMA/SB occurrence by analysing CAP and electroencephalographic (EEG) activities. The analysis was performed on the sleep recordings of 8 SB subjects and 8 controls who received sensory stimulations during sleep. Baseline and experimental nights were compared for sleep variables, CAP, and EEG spectral analyses using repeated measure ANOVAs. Overall, no differences in sleep variables and EEG spectra were found between SB subjects and controls. However, SB subjects had higher sleep instability (more phase A3) than controls (P= 0·05). The frequency of phase A3 was higher in the pre-REM sleep periods (P < 0·001), where peaks in RMMA/SB activity were also observed (P = 0·05). When sleep instability was experimentally increased by sensory stimuli, both groups showed an enhancement in EEG theta and alpha power (P = 0·04 and 0·02, respectively) and significant increases in sleep arousal and all CAP variables. No change in RMMA/SB index was found within either groups (RMMA/SB occurred in all SB subjects and only one control during the experimental night). These findings suggest that CAP phase A3 may act as a permissive window rather than a generator of RMMA/SB activity in predisposed individuals.

The majority of patients suffering from musculoskeletal chronic widespread pain (CWP) are females, and they tend to report poor sleep. We tested the hypothesis that the poor sleep of female patients reporting CWP is gender specific for changes in (1) electroencephalograph (EEG) features and (2) heart rate variability (HRV). Twenty-four normal sleepers were compared to 24 patients with CWP who complained of poor sleep. Patients were referred from general practice and were matched for age (41-47 years) and gender (25 W, 23 M). Sleep variables and spectral EEG activity analyses were performed during 1 night of sleep recording. Time-domain cardiac RR interval and spectral autoregressive analyses were also performed from the same data set. Compared to normal females, female patients with CWP had significantly shorter sleep duration (-68 min), lower sleep efficiency (-9.9%), twice the awakenings and a trend for more periodic limb movements per hour of sleep. Daytime napping was reported by 78% of CWPs. Compared to all controls, females with CWP had significantly less power in the EEG delta band in the first and second non-REM sleep cycle. Although RR interval analysis revealed that CWP patients had a faster heart rate, neither the sympathetic nor sympathovagal analysis reached statistical significance for gender or pain status comparisons. Female CWP patients have shorter sleep duration with many awakenings and lower sleep EEG delta activity without gender difference in HRV.

Purpose: This study investigated whether the presence of tooth wear in young adults can help to discriminate patients with sleep bruxism (SB) from control subjects. Materials and Methods: The tooth wear clinical scores and frequency of sleep masseter electromyographic activity of 130 subjects (26.6 +/- 0.5 years) were compared in this case-control study. Tooth wear scores (collected during clinical examination) for the incisors, canines, and molars were pooled or analyzed separately for statistics. Sleep bruxers (SBrs) were divided into two subgroups according to moderate to high (M-H-SBr; n = 59) and low (L-SBr; n = 48) frequency of masseter muscle contractions. Control subjects (n = 23) had no history of tooth grinding. The sensitivity and specificity of tooth wear versus SB diagnosis, as well as positive and negative predictive values (PPV and NPV), were calculated. One-way analysis of variance and the Mann-Whitey U test were used to compare groups. Results: Both SBr subgroups showed significantly higher tooth wear scores than the control group for both pooled and separated scores (P <.001). No difference was observed between M-H-SBr and L-SBr frequency groups (P =.14). The pooled sum of tooth wear scores discriminates SBrs from controls (sensitivity = 94%, specificity = 87%). The tooth wear PPV for SB detection was modest (26% to 71%) but the NPV to exclude controls was high (94% to 99%). Conclusions: Although the presence of tooth wear discriminates SBrs with a current history of tooth grinding from nonbruxers in young adults, its diagnostic value is modest. Moreover, tooth wear does not help to discriminate the severity of SB. Caution is therefore mandatory for clinicians using tooth wear as an outcome for SB diagnosis. Int J Prosthodont 2009;22:342-350.

PURPOSE: The objective of this experimental study was to assess the efficacy and safety of a reinforced adjustable mandibular advancement appliance (MAA) on sleep bruxism (SB) activity compared to baseline and to a mandibular occlusal splint (MOS) in order to offer an alternative to patients with both tooth grinding and respiratory disorders during sleep. MATERIALS AND METHODS: Twelve subjects (mean age: 26.0 +/- 1.5 years) with frequent SB participated in a short-term (three blocks of 2 weeks each) randomized crossover controlled study. Both brain and muscle activities were quantified based on polygraphic and audio/video recordings made over 5 nights in a sleep laboratory. After habituation and baseline nights, 3 more nights were spent with an MAA in either a slight (25%) or pronounced (75%) mandibular protrusion position or with an MOS (control). Analysis of variance and Friedman and Wilcoxon signed-rank tests were used for statistical analysis. RESULTS: The mean number of SB episodes per hour was reduced by 39% and 47% from baseline with the MAA at a protrusion of 25% and 75%, respectively (P <.04). No difference between the two MAA positions was noted. The MOS slightly reduced the number of SB episodes per hour without reaching statistical significance (34%, P =.07). None of the SB subjects experienced any MAA breakage. CONCLUSION: Short-term use of an MAA is associated with a significant reduction in SB motor activity without any appliance breakage. A reinforced MAA design may be an alternative for patients with concomitant tooth grinding and snoring or apnea during sleep.