Modulating cortical excitability through transcranial direct current stimulation combined with therapeutic exercise for craniofacial myofascial pain: Randomized controlled trial.

BACKGROUND

Temporomandibular dysfunction (TMD) involves pain, motor impairment and psychological distress, often sustained by maladaptive central neuroplasticity. Transcranial direct current stimulation (tDCS) can modulate cortical excitability, enhance descending inhibitory control, and improve function, making it a promising adjunct to multimodal rehabilitation.

OBJECTIVE

To examine the effects of tDCS combined with multimodal rehabilitation on pain, motor performance and psychosocial outcomes in TMD and to explore associated neurophysiological mechanism.

METHODS

In this randomized, assessor-blinded trial, participants received either active tDCS plus rehabilitation or Sham tDCS plus rehabilitation. Assessments occurred at baseline, post-intervention (8 weeks) and at 3 and 6-month follow-up. Primary outcomes were EEG Alpha Modulation Index (AMI), Pressure pain threshold (PPT) and Jaw functional limitation scale (JFLS); secondary outcomes included neck disability index (NDI), patient global impression of change (PGIC) data were analyzed via repeated-measures ANOVA with intention-to-treat principles.

RESULTS

Active tDCS with rehabilitation produced greater improvements than sham in all outcomes (p < 0.001). EEG Alpha Modulation Index increased (η 2 = 0.24), indicating enhanced cortical excitability. PPT improved (η 2 = 0.22) showed significant and sustained functional gains. PGIC scores indicated large perceived improvement (r = 0.72), maintained at 6 months. No serious adverse events were reported. Minor events (headaches, tingling, skin irritation) occurred in <10 % of sessions and were transient.

CONCLUSION

tDCS combined with therapeutic exercise safely enhances cortical excitability, pain modulation, function and patient outcomes in TMD, supporting Multimodal rehabilitation. Further research should refine protocals and confirm long-term benefits across populations.