Evaluation of the Efficacy of Neuromodulation in the Control of Chronic Orofacial Pain

Summary

Chronic orofacial pain significantly affects patients' quality of life, compromising essential functions such as chewing and speech. Although conventional treatments are available, many patients do not achieve adequate and lasting relief. This project investigates the effectiveness of neuromodulation techniques, namely transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS), as innovative therapeutic alternatives for the control of chronic orofacial pain.

The study will be conducted in adult patients diagnosed with orofacial pain. Participants will be divided into two groups: one group will receive active neuromodulation (tDCS or TMS) and the other a sham treatment (placebo). Sessions will take place daily over two weeks. Assessments will include pain intensity, pain pressure threshold, masticatory function, and bite strength, in order to observe any functional changes.

The group undergoing neuromodulation is expected to show a significant reduction in pain levels and improvements in quality of life compared to the placebo group. This study could support the adoption of neuromodulation as a complementary approach in the treatment of chronic orofacial pain, offering an effective and non-invasive alternative for patients who do not respond to conventional treatments.

Conditions

• Orofacial Pain

Interventions

DEVICE

Active Neuromodulation (tDCS or TMS)

Participants receive active non-invasive neuromodulation using either transcranial direct current stimulation (tDCS) or transcranial magnetic stimulation (TMS). For tDCS, stimulation is delivered with 35 cm² electrodes, 1-2 mA, for 20 minutes, with the anode placed over C3 or C4 contralateral to the pain side, for five consecutive sessions. For TMS, stimulation is delivered with a figure-of-eight coil targeting the motor cortex corresponding to the orofacial region, following established safety protocols (e.g., 10 sessions across two weeks). All procedures follow standardized therapeutic parameters aiming to modulate cortical excitability and reduce pain.

DEVICE

Sham Neuromodulation (tDCS or TMS)

Participants receive sham stimulation designed to mimic the sensory experience of tDCS or TMS without producing physiological neuromodulatory effects. For tDCS, the device uses brief ramp-up/ramp-down currents to simulate tingling without active stimulation. For TMS, a sham coil or angled coil is used to reproduce acoustic and scalp sensations while preventing magnetic induction. Session duration, procedures, and interaction with the operator are identical to the active arm to maintain blinding integrity.

Sponsors & Collaborators

• University of Sao Paulo

  collaborator OTHER

• University of Aarhus

  collaborator OTHER

• Universidade Federal de Alfenas

  collaborator OTHER

• Egas Moniz - Cooperativa de Ensino Superior, CRL

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

TRIPLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

75 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2025-11-01

Primary Completion

2026-05-01

Completion

2026-08-01

Countries

• Portugal

Study Locations