Reduction of TMD pain by high-frequency vibration: a spatial and temporal analysis.
Under some conditions, vibration delivered to the skin can reduce pain (vibratory analgesia). Previous studies of this phenomenon in a clinical context have been somewhat variable in terms of stimulus control, and have not examined the way in which the spatial distribution of pain is affected. In the present study, we used rigorously controlled conditions to examine vibratory analgesia in participants (N=17) with painful temporomandibular disorders (TMD). Results of 20- and 100-Hz vibration were compared with data from a no-vibration control condition. The results document for the first time that vibratory analgesia occurs in TMD chronic pain conditions. We measured its time course using continuous visual analog scale (VAS) recording, and its spatial aspects by asking subjects to indicate painful regions on standardized drawings. VAS ratings and drawings both showed that pain is reduced by 100-Hz, but not by 20-Hz, vibration. The effectiveness of the high-frequency vibration cannot be attributed to a mechanism involving Pacinian corpuscles, since these receptors are lacking in the skin of the orofacial region. Spatial analyses revealed that ipsilateral and contralateral effects of vibration were statistically equivalent, suggesting that vibratory analgesia relies at least in part on central nervous system processes rather than local mechanisms.
Roy
Elizabeth A
EA
Department of Psychology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA Dental Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Hollins
Mark
M
Maixner
William
W
D000293:Adolescent; D000328:Adult; D002908:Chronic Disease / Q000628:therapy; D005145:Face / Q000503:physiopathology; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008875:Middle Aged; D059408:Pain Management; D010147:Pain Measurement / Q000379:methods; D011601:Psychophysics; D011930:Reaction Time; D016353:Self-Examination / Q000379:methods; D012684:Sensory Thresholds; D013705:Temporomandibular Joint Disorders / Q000628:therapy*; D016896:Treatment Outcome; D014732:Vibration / Q000627:therapeutic use*