Following the guidelines, 5 sessions of education, cognitive behavioural tools, jaw exercises and manual therapy will be conducted.

The educational sessions will teach about TMD and basic pain concepts. A single type of cognitive behavioural tool will be employed. The aim will be to decrease bruxing and parafunctional activity during wakefulness. This will be done by training the jaw relaxation position, which will then be generalised to activities of daily living with the help of some conditioning through positive and negative reinforcement. Exercise activities will aim to train motor control, strength and mobility. Manual therapy will be carried out in the orofacial region by means of soft tissue techniques and joint mobilisation.

Scale assessing kinesiophobia or fear of movement or injury in patients with TMD.

The scale consists of a total of 11 items. In each of the items, the user must indicate his or her degree of agreement with each of the statements presented. In this way, it is scored using a Likert-type scale from 1 (totally disagree) to 4 (totally agree), with higher scores being indicators of greater fear of movement.

It has an Internal Consistency (Cronbach's α) of 0.843.

It is a self-administered questionnaire that assesses the patient's fear-avoidance beliefs about physical activity and work. It assesses activities of daily living, behaviour, functional mobility, general health, participation, mental health, motivation, occupational performance, pain, personality, quality of life, self-efficacy, stress and coping. It consists of 16 items in which the patient scores his or her degree of agreement or disagreement with the statement proposed in each item, using a 7-point Linkert-type scale. Where 0 symbolises complete disagreement and 6 complete agreement. The maximum score that can be obtained is 96 points, with higher scores indicating higher fear-avoidance beliefs. It consists of two subscales: the work subscale (FABQw) with 7 questions and a maximum score of 42 points, and the physical activity subscale (FABQpa) with 4 questions and a maximum score of 24.

ICC=0.97,FABQpa CI=0.77,FABQw=0.88. The total maximum score that can be obtained is 96 points

To assess the perception of jaw function. Consists of two dimensions of 17 items in total that assess the degree of disability of various specific jaw functions. Each item is scored on a scale from 0 to 4, where 0 represents no difficulty and 4 represents extreme difficulty in performing a specific task. The sum results in a scale from 0 to 68, where higher scores represent a greater degree of disability.

The overall Internal Consistency of the scale is Cronbach's α =0.94, with Cronbach's α =0.87 for the first dimension and Cronbach's α =0.92 for the second dimension.

Quantification of the maximum jaw opening distance by measuring the upper and lower interincisive space during maximum jaw opening with a caliper (in millimetres). Three consecutive measurements shall be taken and the average of the three shall be recorded. It shall be measured in two ways: active maximum mandibular opening (MMO) and comfortable maximum opening (MCO). This type of measurement is frequently used in other similar articles.

The presence and type of intra-articular sounds will be confirmed pre-intervention by the investigator collecting the data using a stethoscope placed over the mandibular condyle during the exploration of TMJ movement.

The procedure used to subjectively analyse intra-articular sounds has been described in other studies previously. To quantify the intensity of intra-articular sounds a numerical scale (NRS 0-10) will be used, the frequency will be reported by selecting one of the following options: 0 No joint sounds, 1 Joint sounds once or twice/week, 2 Joint sounds three/four times per week, 3 Joint sounds ≥ five times/week.

Exercise fatigue will be assessed using the Borg Scale, which has been used in other research to measure fatigue in different physical exercise contexts. This scale of perceived exertion measures the degree of effort that the individual perceives when doing a given exercise on a numerical scale from 0 to 10, where 0 is total rest and 10 is maximum effort. This tool will be used during each of the exercise sessions to ensure that the programmed intensity is met.

The Big Five (BFQ) is a five-factor model to describe personality.. It uses a Likert-type scale consisting of 132 questions with five response options ranging from 'completely false for me' to 'completely true for me'. It identifies the five fundamental dimensions for describing and assessing personality (open-mindedness, emotional stability, responsibility, agreeableness, energy) and their respective sub-dimensions (openness to experience, openness to culture, impulse control, emotion control, perseverance, conscientiousness, friendliness, cooperation, dominance, dynamism). The Internal Consistency of Cronbach's alpha test has a significant value of 0.874 for the five scales and the ten subscales. When reporting a score on the BFQ, the total score ranges from 132 to 660, with higher scores indicating greater alignment with the positive characteristics of each personality dimension. Higher scores generally reflect better outcomes in terms of personality traits associated with positive

The instrument consists of 33 items divided into three subscales assessing: (a) internal locus of control, which refers to people's beliefs about whether their pain is influenced by personal actions ('I can prevent pain if I avoid certain situations that make me nervous'; Cronbach's α = 0. 86); (b) locus of control by chance, determined by the degree to which a person believes that their pain is due to chance ('my pain cannot be controlled'; Cronbach's α = 0.84); and (c) locus of control by health professionals under the belief that their pain will be relieved by health professionals ('my doctor's treatment can help me reduce my pain'; Cronbach's α = 0.88). Responses to the instrument were made on a five-point scale, ranging from strongly disagree to strongly agree. Higher scores on the scale indicate a stronger belief in control over pain through internal factors, health professionals, or chance, depending on the subscale.

The pressure algometer is an instrument with a circular disc on which the pressure measurements are displayed (with a range of 5 kg, divided into 10 parts of half a kilogram), and a rubber tip with a circular surface of 1 cm2, which allows the pressure force to be transferred to deep tissues. The FPK 60 Analogue Algometer will be used in this study.

Its application follows the protocol proposed by another similar study. The tip of the algometer will be applied perpendicular to the muscle and a pressure will be maintained, progressively increasing at 1 kg/sec. Subjects will be instructed to make a signal at the moment they experience pain, in order to have an accurate record (pain threshold). The points where algometry will be performed are: masseter, temporalis and trapezius muscles and the suboccipital level.

This inventory was developed to assess patterns of psychosocial symptoms present in individuals, and can be used in both community tasks and clinical diagnosis. Each of the 90 items is answered on a five-point scale (0-4). It is assessed and interpreted according to nine primary dimensions and three global indices of psychological distress: (1) somatizations (SOM), (2) obsessions and compulsions (OBS), (3) interpersonal sensitivity (SI), (4) depression (DEP), (5) anxiety (ANS), (6) hostility (HOS), (7) phobic anxiety (FOB), (8) paranoid ideation (PAR), (9) psychoticism (PSIC) and other indices such as (1) global severity index (GSI), (2) total positive symptoms (TSP) and (3) positive symptomatic distress index (PSDI). In spanish population; CI=0.72-0-96, in terms of chronic pain; CI=0.78-0,97. Higher scores on this inventory indicate more significant psychosocial symptoms and distress, which may be relevant in diagnosing psychological conditions or assessing the impact of chronic pain

A multidimensional inventory, developed to assess different forms of stress coping. Five of its scales (four items each) conceptually measure different aspects of problem-focused coping (active coping, planning, suppression of distracting activities, restraining coping, seeking instrumental social support). This scale has an Internal Consistency of between 0.71 and 0.80 as measured by Cronbach's alpha. Minimum score: 0 (indicating no use of the particular coping strategy). Maximum score: 4 (indicating maximum use of the coping strategy).

A self-report instrument that assesses the level of perceived stress over the past month, it consists of 14 items with a five-point scale response format (0 = never, 1 = hardly ever, 2 = occasionally, 3 = often, 4 = very often). The total PSS score is obtained by inverting the scores of items 4, 5, 6, 7, 9, 10 and 13 (as follows: 0=4, 1=3, 2=2, 3=1 and 4=0) and then adding the 14 items. The direct score obtained indicates that a higher score corresponds to a higher level of perceived stress. This scale has an Internal Consistency of 0.81 and a test-retest validity of 0.73. Higher scores indicate a higher level of perceived stress in the past month. Lower scores suggest that the individual has experienced lower levels of perceived stress.

A questionnaire intended to assess individuals' anxiety level. More specifically, the STAI measures individuals' predisposition to perceive various stimuli as threatening (i.e. trait anxiety). Thus, an individual with high trait anxiety is more likely to produce an anxiety response. It includes 40 items (i.e. 20 for each subscale), the response scale ranges from 0 to 3 points. In the State Anxiety subscale, item scores range from 0=not at all [not at all], 1=somewhat [somewhat], 2=quite a bit [moderately], and 3=very much [a lot]. In the Trait Anxiety subscale, response options range from 0=almost never [almost never], 1=sometimes [sometimes], 2=often [often], and 3=almost always [almost always]. Although each subscale has a theoretical range of 20 to 80, the scores can be compared with those of the original scale by adding 20 to the scores obtained.The Cronbach's alpha for this scale is 0.82. Higher scores on either subscale indicate higher levels of anxiety.

A brief screening test for the identification of mild cognitive impairment and early dementia processes. The total score of the MoCA test is 30 points, and the administration time is 7-10 ms. It is validated in the Spanish population between 18 and 90 years of age. It assesses the general cognitive status of the individual through different cognitive domains. Total score: The maximum score is 30 points, and the minimum score is 0 points. A higher score indicates better cognitive functioning, while a lower score suggests a higher likelihood of cognitive impairment. Typically, a score below 26 points may indicate possible cognitive impairment, though interpretation should consider other factors such as education level and clinical context.

The educational level was obtained through the question 'What is the highest level of education you have completed?', where 8 options could be selected (1. primary education or lower, 2. secondary education, 3. baccalaureate, 4. vocational training, 5. degree studies).