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

The Numerical Pain Rating Scale will be used to assess pain intensity in this trial. It consists of a sequence of numbers from 0 to 10, in which 0 represents "no pain" and 10 represents "worst pain imaginable".

The Craniofacial Pain and Disability Inventory (CF-PDI) is a self-administered questionnaire that measures the outcomes of pain and disability related to craniofacial pain. It demonstrated a good structure, internal consistency, reproducibility, and construct validity. Also, the Brazilian Portuguese version showed acceptable psychometric measurements. It consists of 21 items, with a score ranging from 0 to 63 points. Each question is scored on a 4-point ordinal scale, ranging from 0 to 3. A higher score reflects higher disability levels.

The Pain Self-Efficacy Questionnaire (PSEQ) will be used to measure pain self-efficacy beliefs (ability to function despite pain). Each item is rated by selecting a number on a 7-point scale, where 0 equals ''not at all confident'' and 6 equals ''completely confident''. A total score is calculated by summing the scores for each of the 10 items, resulting in a maximum possible score of 60. Higher scores reflect stronger self-efficacy beliefs. In the study analyzing the measurement properties of the Brazilian Portuguese version, the reliability of the PSEQ was considered adequate (the correlation divided in half was 0.76 and the internal consistency was 0.90).

The kinesiophobia outcome will be measured using the Tampa Scale For Kinesiophobia for Temporomandibular Disorders (TSK/TMD-Br). This is an 18-item self-report instrument that assesses fear of movement. The version translated into Brazilian Portuguese, TSK/TMD-Br, has 12 items. Each item is scored on a 4-point Likert scale, ranging from "strongly disagree" (score = 1) to "strongly agree" (score = 4). Responses are summed to produce a total score in which higher values reflect greater fear of movement (12-48 points) The TSK/TMD has good reliability (CCI = 0.66-0.83) and acceptable validity values (VISSCHER et al., 2010). Internal consistency analysis demonstrated adequate Cronbach's α values (>0.70) for all domains and reliability demonstrated excellent ICC values for all domains (ICC>0.75).

The Global Perceived of Effect of improvement has 11 points and ranges from -5 ("much worse") to 0 ("no change") to +5 ("completely recovered"). A higher score indicates greater recovery from the condition.

The CARE Empathy Scale measures the degree of perception of empathy on the part of the patient, which can influence the effectiveness of the intervention. The instrument consists of 10 items, with additional explanations of colloquial language, aiming to facilitate understanding of the questions. The answers range from 1 "poor" to 5 "excellent". All item values are then added together, providing a final score between 10 and 50. The version translated into Brazilian Portuguese has a Cronbach's alpha coefficient of 0.867.

The Neurophysiology of Pain Questionnaire (NPQ) will be used to verify learning related to the pain neuroscience education program. The 19 items have the following response options: true, false, undecided. Each correct question receives a score of 1. Incorrect answers and/or answers marked as undecided are not scored. The NPQ is scored out of 19 with 1 point awarded for each correct response. A score of 0 is attributed to incorrect responses and those marked as undecided. The internal consistency analysis revealed a reliability value of alpha = 0.63.

The Concept Of Pain Inventory for Adults (COPI-ADULT) will be administered to assess participants' beliefs about pain. This instrument consists of 13 items. The items are presented on a 5-point Likert scale: 0 strongly disagree; 1 disagree; 2 I'm not sure; 3 agree and 4 strongly agree. Higher COPI-Adult scores reflect greater alignment with contemporary pain science (total scores can range from 0 to 52). It presents acceptable internal consistency (α=0.78) and good test-retest reliability at 1 week (intraclass correlation coefficient of 0.84 (95% confidence interval: 0.71-0.91).

The Exercise Adherence Assessment Scale (EARS-Br) is made up of six items that assess the exercise behavior adherence and has 5 possible answer options (0 = completely agree to 4 = completely disagree), the total score ranges from 0 to 24 points, the higher the score, the greater the adherence. The structure of the single-factor EARS-Br instrument with 6 items showed acceptable fit indices (comparative fit index and goodness-of-fit index > 0.90 and root mean square error of approximation < 0.08). The EARS-Br scale showed acceptable internal consistency (α = 0.88) and excellent reliability (ICC = 0.91). A Minimally Important Change (MIC) of 5.5 in the EARS-Br total score was considered a significant change in adherence behavior (AUC = 0.82). Moderate accuracy (AUC = 0.89) was obtained for a total EARS cutoff score of 17/24 after home exercise prescription. Sensitivity and specificity are also acceptable (greater than 80%).