Objectives: Objectives: Catastrophic interpretations of pain are associated with amplified pain experience but little is known about effects on muscle activity. The aims were to (a) determine pain effects on jaw muscle electromyographic (EMG) activity and (b) examine whether pain catastrophizing correlates with any such effects.
Methods: Method: 25 asymptomatic adults (35±7 years) were categorized as high (n=11) or low (n=14) catastrophisers (Pain Catastrophizing Scale). Muscle electromyographic (EMG) activity using bipolar surface electrodes from right (R) and left (L) masseter (M), anterior temporalis (AT), digastric (D) and sternocleidomastoid (SCM) muscles] was recorded during standardized empty chewing (i.e. no food bolus and standardised by visual feedback chewing cycle frequency and amplitude). Jaw muscle activity was calculated in each subject as the difference between induced moderate pain (5% saline tonic infusion into right masseter muscle) and non-pain (isotonic saline infusion) conditions of root mean square EMG activity at every 0.5mm jaw displacement of the chewing cycle. Mean muscle activity for each group was compared with STATISTICAL TEST.
Results: Results: In all subjects, the LAT EMG activity (P<0.01) was significantly lower during pain in comparison with non-pain conditions. During opening, Muscle activities of the LD (P<0.05) during opening and the RM (P<0.05) and LAT (P<0.01) during closing phases of chewing were significantly less in high catastrophizers. PCS scores were significantly negatively correlated with muscle activities of LD (P=0.02) and RSCM (P=0.04) during opening, and LAT (P=0.01) during closing phases.
Conclusions: Conclusion: Pain catastrophizing may play an important role in influencing pain’s effect on jaw muscle activity. These findings may have clinical implications because not only pain but also related catastrophic thoughts may need to be addressed in the management plan. Support: Australian NHMRC, Australian Dental Research Foundation.
Division: IADR/AADR/CADR General Session
Meeting:2015 IADR/AADR/CADR General Session (Boston, Massachusetts) Location: Boston, Massachusetts
Year: 2015 Final Presentation ID:4506 Abstract Category|Abstract Category(s):Oral Health Research
Authors
Akhter, Rahena
( Charles Sturt University
, Orange
, New South Wales
, Australia
; The University of Sydney
, Westmead
, New South Wales
, Australia
)
Svensson, Peter
( Arhus University
, Arhus
, Denmark
)
Benson, Janet
( The University of Sydney
, Westmead
, New South Wales
, Australia
)
Nicholas, Michael
( Pain Management Research Institute, Northern Clinical School
, Sydney
, New South Wales
, Australia
)
Peck, Christopher
( The University of Sydney
, Westmead
, New South Wales
, Australia
)
Murray, Gregory
( The University of Sydney
, Westmead
, New South Wales
, Australia
)
Support Funding Agency/Grant Number: Australian NHMRC, Australian Dental Research Foundation
Financial Interest Disclosure: None