Publications
Permanent URI for this collection
Browse
Browsing Publications by Department "Aarhus University"
Results Per Page
Sort Options
-
PublicationBlood oxygenation of masseter muscle during sustained elevated muscle activity in healthy participants(Blackwell Publishing Ltd, 2016-12-01)
;Suzuki S. ;Arima T. ;Kitagawa Y.Svensson P.Myofascial pain associated with temporomandibular disorders has often been linked to pathological muscle hyperactivity. As a result, localised disturbances of intramuscular blood flow could lead to a lower level of oxygen distribution, hypoxia and microcirculatory changes. To assess haemodynamic changes in the masseter muscle during sustained elevated muscle activity (SEMA). Sixteen healthy participants performed thirty 1-min bouts of SEMA with intervals of 1-min ‘rest’ periods between the bouts on a bite force transducer device. The participants completed three sessions with different percentage of their maximal voluntary occlusal bite force (MVOBF): 0% (no task), 10% or 40% MVOBF tasks. The order of the sessions was randomised with 1- to 2-week intervals. Haemodynamic characteristics of the masseter muscle were estimated with use of a laser blood oxygenation monitor. Tissue blood oxygen saturation (StO2) during SEMA was lower than during rest (P < 0·001). The relative changes in total haemoglobin (Total-Hb) and StO2 were influenced by condition (SEMA and rest) and with interactions between condition and session (0%, 10% and 40% MVOBF tasks). These results suggest that SEMA may lead to hypoxia in the masseter muscle and that the haemodynamic characteristics and muscle symptoms depend on the magnitude of muscle contractions. Overall, the present findings may help to provide better insights into relationships between jaw muscle activity, haemodynamic changes and symptom developments with implications for clinical conditions such as bruxism characterised by different levels of tooth-grinding and tooth-clenching muscle activity. -
PublicationEffect of contingent electrical stimulation on jaw muscle activity during sleep: A pilot study with a randomized controlled trial design( 2013-09-01)
;Jadidi F. ;Nielsen P. ;Baad-Hansen L.Svensson P.Objective. To determine the effect of contingent electrical stimulation (CES) on jaw muscle activity during sleep in a double-blinded randomized controlled trial (RCT). Materials and methods. Eleven patients with myofascial TMD (mean age 37 years) and with a clinical diagnosis of bruxism were included. EMG activity (Grindcare®) was recorded from the anterior temporalis muscle during sleep and analyzed online. Jaw muscle activity related to clenching or grinding triggered an electrical square-wave pulse train (450 ms) adjusted to a clear, but non-painful intensity. TMD patients were randomized into two groups: active treatment with CES or no CES (placebo). Number of EMG episodes/hour sleep was the primary outcome parameter. The following variables were assessed as secondary outcome parameters; number of painful muscles, maximum pain-free jaw opening, characteristic pain intensity, depression scores and Oral Health Impact Profile scores. Numerical Rating Scale scores for self-reported pain and muscle tension were registered for at least 4 nights per week during the experiment. Results. The number of EMG episodes/hour sleep was significantly reduced (52 ± 12%) in the CES group during the sessions with CES (ANOVA: p = 0.021) compared to baseline. There were no significant differences in the secondary outcome parameters (ANOVA: p > 0.513) or pain or muscle tension scores between groups (p = 0.645). The average duration of sleep hours during the nights with and without CES was not significantly different (p = 0.646). Conclusions. These results demonstrate a significant inhibitory effect of CES on jaw muscle EMG activity during sleep in a RCT, but with no effects on self-reported pain. © 2013 Informa Healthcare.