Perhaps the most straightforward finding from the present study is that out of the 102 individuals initially considered, 24 of them suffered from myalgia, although the majority of these participants did not consider it severe enough to request professional help. Only 24 participants did not present any TMD related symptom or signs.
It should be noted that the participants were university students (a specific subgroup of young adults) and a more representative sample would have increased the study validity. Nevertheless, the percentage of students suffering TMD matches population prevalence suggested by other studies [7,36,37,38,39]. Furthermore, participants average score of the psychological questionnaires were similar to others Spanish university students (Spain), since percentiles where within 40 and 60 (See table 2), except for anxiety trait and logical analyses (30 and 35, respectively), according to norms provided by questionnaire manuals [32,33,34]. In addition, the sample selection (a cohort of university students) favored the homogeneity of the samples in terms of age, sociological, cultural and environmental variables. Nonetheless, it should be taking in account that even though the myalgia group clearly fulfilled the diagnostic criteria, they weren’t severe patients seeking consultation. The fact that psychological alterations are already present in non-severe patients would support their importance in chronic and more severe TMD patients.
In accordance with previous studies, the myalgia group showed higher levels of trait anxiety than the control group [2–4,8,9,13,25,40] However, while the OPPERA prospective cohort study detected significantly larger levels of trait and state anxiety for TMD patients , in the present study state anxiety differences were not of significance. This might be due to a high level of homogeneity between the myalgia and control groups, a cohort of university students, which were probably facing similar social and environmental demands. Alternatively, this could also be due to a lack of power resulting from the number of participants, since data analyses for anxiety scores revealed small size effects and powers. In addition, the present sample included participants suffering exclusively from myalgia. According to the present data, higher anxiety levels in myalgia might appear mainly because of the individuals’ traits, regardless of the situation, at least for young adult students.
Though neuroticism seems to be strongly associated with TMD [3,13], the OPPERA cohort study found that it was a weak predictor of TMD. Nonethless, the later study did not differentiate between articular and muscular TMD pathologies. Ferrando et al.  showed that myofascial patients present higher levels of depression and neuroticism, whereas conscientiousness and self-discipline were higher in the articular group. Similarly, present findings show that myalgic participants have larger levels of neuroticism than controls. Altogether, these results suggest that neuroticism might be an important personality factor contributing to TMD, at least for myalgia.
Coping styles were thoroughly investigated by means of the CRI inventory in the present study. Acceptance and Resignation as well as Seeking Alternative Reward were more prevalent in myalgia group than in the control group. In addition, the myalgia group used significantly more often avoidance coping strategies. Therefore, it could be said that myalgia patients, in comparison to controls, tend to face a problem by looking for distractions, avoiding the problem and accepting that they can do nothing to solve it. Avoidance coping strategies are often regarded as maladaptive. Furthermore, maladaptive coping is related to depression and anxiety, . TMD patients seem to cope with stress differently than individuals from the general population. In line with the present findings, an increase of escape-avoidance strategies for TMD patients have been previously described, which were interpreted as maladaptive [24,26]. In this line, a recent study found that avoidance and passive coping strategies might worsen oral health-related quality of life in patients with myalgia . In contrast, some studies have observed higher levels of active coping in masticatory muscle pain patients in comparison with articular pain patients [17,29,30], although a symptomless control group was not included, making comparisons harder to establish. In contrast to previous research, the present study did not identify reduced adaptive coping strategies in the myalgia group. It should also be considered, however, that the participants were young students presenting myalgia, unlike previous studies, where the lack of adaptive coping strategies might well appear as a consequence of long lasting and more severe TMD and/or aging. Nonetheless, the differences in the assessment and definition of coping strategies across the few TMD coping studies in the literature make similarities hard to establish. For example, seeking an alternative reward, which is classified as an avoidance strategy, according to the coping model in the present study  is sometimes conceptualized as an adaptive strategy instead of maladaptive, especially in situations where things cannot be changed . Nonetheless, the majority of participants, when asked in the CRI, reported stress in situations where output clearly depended on their behavior, such as university exams.
The way people face problems or stressful situations and the way in which they interpret them, might be an important key to explain why some individuals might have more chances to develop a myalgia. The data supports this hypothesis, as it indicated larger levels of maladaptive coping styles, but not of state anxiety, for myalgia patients in comparison to the control group. The well-known OPPERA study investigated pain coping, but not general coping strategies. However, they established that perceived stress increased the risk of first-onset TMD [14,17,42]. Perceived stress has been negatively related to emotional intelligence and to adaptive coping strategies. Specifically, maladaptive coping strategies might increase perceived stress, a strong predictor of TMD [43,44].
In a follow up of the OPPERA study, it was recently reported that psychological and social variables changed in parallel with TMD status . Therefore, interventions to prevent maladaptive coping styles and encourage adaptive coping tailored to the needs of myalgia patients might improve general treatment and recovery 
The present study clearly points out the importance of coping styles in myalgia, although several limitations should be addressed for future research. A sample of dentistry students guarantees, on the one hand, the accuracy of symptoms detection (because of their symptoms awareness, and their knowledge about them), and on the other hand a similar environment, educational level, and lifestyle between myalgic participants and controls. However, as discussed above, case group included young students presenting myalgia, even though they clearly fulfilled the diagnostic criteria, they weren’t severe patients seeking consultation. Therefore, further research including patients and a larger and more heterogenic sample of people could enhance the generalizability of the results. In addition, psychological factors should be investigated taking into account the TMD subtypes proposed by the new DC/TMD classification.