Temporomandibular disorder (TMD) refers to a group of musculoskeletal conditions that affect the temporomandibular joint (TMJ), the masticatory muscles, and the associated structures. It is assumed that 30 to 40% of cases of acute painful TMD becomes chronic. Chronic pain is a significant public health problem, affecting professional and social activities, emotional state, and quality of life. The pathophysiological mechanisms involved in chronic orofacial pain are complex and multifaceted and not yet fully understood. The coexistence of psychological factors associated with vast peripheral and central mechanisms makes chronic orofacial pain treatment a complex challenge. Due to the complexity of chronic TMDs, some patients remain refractory to current therapeutic methods. Thus, several efforts have been made to develop therapies aimed at the treatment of neuroplastic changes induced by chronic pain. In this sense, transcranial stimulation methods appear to be a promising technique. Transcranial Magnetic Stimulation (TMS) is a non-invasive, safe, and approved treatment for clinical use in psychiatric disorders such as depression and chronic pain. Given the above, it is necessary to develop studies to investigate the TMS effectiveness in chronic TMD. This study aims to evaluate the effectiveness of transcranial magnetic stimulation in patients with chronic temporomandibular disorders. An additional objective is to determine possible predictors for treatment success based on the assessment of functional brain connectivity and psychosocial characteristics.
Individuals of both sexes, literate, aged over 18 years with the diagnosis of muscular and/or joint TMD by the Diagnostic Criteria for Temporomandibular Disorders (DC-TMD).
Pain duration longer than 6 months.
Intensity of orofacial pain greater than 5 on the visual analogue scale (VAS).
Volunteers who present verbal communication impairment due to a neurological disorder, a sequel to a previous illness, or a psychiatric condition.
Pregnant women
Individuals with any impediment to MRI: having a pacemaker or implantable defibrillator, cochlear implant, ferromagnetic aneurysm clips, electrodes used for deep brain stimulation, ocular implants, Swan-Ganz catheter, orthopedic prostheses or metallic bodies close to the area of interest.
Individuals with any contraindication for transcranial magnetic stimulation: have focal or generalized encephalopathies, increased intracranial pressure, and severe heart disease; history of head trauma, epilepsy, and individuals with first-degree relatives diagnosed with idiopathic epilepsy; use of drugs that lower the seizure threshold (tricyclic antidepressants and antipsychotics); chronic use of alcohol or epileptogenic drugs.