Pain Science Education Administered in Full or Fractioned Dosage Modes for Temporomandibular Disorders

Temporomandibular Disorders (TMD) are a collection of musculoskeletal disorders which affect the masticatory structures and have a multifactorial etiology. A biopsychosocial approach is recommended for the management of these disorders including different interventions like exercise, manual therapy and pain education. The aim of this study is to compare the effect of a full dosage mode pain science education program (2 initial sessions of 45 minutes) versus a fractioned dosage format (6 sessions of 15 minutes) combined with manual therapy and orofacial exercises on primary outcomes - pain intensity and disability - and secondary outcomes - mandibular range of motion, pain-related self-efficacy, kinesiophobia, global perception of improvement, empathy, knowledge about pain neuroscience, beliefs about pain, exercise adherence, and catastrophizing - in patients with chronic painful TMD. This study will be a randomized controlled trial with a sample of 148 participants. Individuals will undergo a screening process to identify those with TMD diagnosis according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD), aged 20 to 60 years, of both genders, and then the volunteers will be randomized into two groups (G1: Full dosage mode pain science education program + Manual therapy/orofacial and neck motor exercises vs. G2: Fractioned dosage mode pain science education program + Manual therapy/orofacial and neck motor exercises). These volunteers will be recruited in the city of São Carlos, SP. The intervention will take place twice a week for 8 weeks, administered by a single therapist, each session lasting 1 hour. The primary outcomes will be pain intensity and disability, assessed using the numerical pain rating scale and the Craniofacial Pain and Disability Inventory (CFP-DI), respectively, and the secondary outcomes will be mandibular range of motion, pain-related self-efficacy, kinesiophobia, global perception of improvement, empathy, knowledge about pain neuroscience, beliefs about pain, exercise adherence, and catastrophizing, assessed using the Tampa Scale for Kinesiophobia for Temporomandibular Disorders (TSK-TMD), Global Perceived Effect of Improvement scale, Pain Self-Efficacy Questionnaire (PSEQ), CARE Empathy Scale, and Pain Catastrophizing Scale (PCS). For statistical analysis, a Generalized Estimated Equations considering time and groups as factors will be used. A significance level of p\<0.05 will be considered.


Eligibility Criteria:
Inclusion Criteria:

* age between 20 and 60 years;
* painful TMD (confirmed by applying DC/TMD);
* complaint of pain with a minimum intensity of 3 (on a scale of 0 to 10) present for at least 3 months;
* fluency to speak and understand Brazilian Portuguese (Mini Cog instrument to assess cognitive capacity and the Cloze Test to certify textual reading comprehension)

Exclusion Criteria:

* history of tumors in the orofacial region;
* central and peripheral neurological diseases;
* uncontrolled psychiatric illnesses;
* pregnant women;
* presence of toothache, neuralgia or chronic painful conditions in the head region, orofacial region or systemic pain (for example, fibromyalgia, osteoarthritis, osteoarthritis or rheumatological diseases);
* report of previous major surgeries in the craniofacial region, such as orthognathic surgeries, TMJ surgeries, or resulting from post-trauma corrections;
* history of major trauma involving the cervical or craniofacial region (facial trauma, whiplash injuries, etc.);
* individuals undergoing physiotherapeutic treatment up to 6 months before the start of this study.