## 4 Discussion
Local pressure may equalize the length of sarcomeres in the involved MTrPs, which would help to dictate the length and tone into the affected tissues [18; 20]. On the other hand, changes in MMO after CT may result from reactive hyperemia in the MTrPs region or a spinal reflex mechanism for the relief of muscle spasm [21]. Although the mechanism of CT has not been clearly explained, the therapeutic effect has been confirmed in several studies [22; 23; 24; 25; 26; 27; 28]. In the study of [PERSON] et al., the decrease in bioelectrical activity after MTrPs compression was related to the improvement of active range of motion, which was also confirmed in the presented work [22]. The study of [PERSON] et al. confirms that a single treatment session of active MTrPs with CT causes a decrease in muscle stiffness [25]. Moreover, [PERSON] et al. observed that a 4-week treatment of MTrPs for CT resulted in a significant improvement in pressure pain sensitivity, mobility, and muscle strength in the short term [26]. On the other hand, the long-term impact of CT on improvement in functional capacities after the 15 treatments was observed by [PERSON] et al. [27]. Based on the systematic review of [PERSON] et al., CT can be recommended in the treatment of neck pain patients with MTrPs [28]. However, current literature lacks research on the CT application in patients with active MTrPs within the stomatognathic system. Within the present study, we provided an objective confirmation of the efficacy of CT from a clinical perspective. Based on the obtained results, CT seems to be effective in the improvement of the active maximal mouth opening and gives significant acute effects on bioelectric masticatory muscle activity. Therefore, a practical application of this study is that CT influencing the functional and resting activity of the masticatory muscles may be useful in the treatment of MTrPs within the stomatognathic system. Thus, future clinical trials are needed to confirm the effectiveness of CT application within masticatory muscles as well as to assess whether it is more effective compared to other techniques such as myofasical release, acupressure, muscle energy technique, or dry needing. In addition, the described procedure can be used as a standardized test protocol for assessing the effectiveness of therapy within the masticatory system. The presented study has several limitations. Firstly, the diagnostics criteria for TMDs were replaced by DC/TMDs in 2014. However, in this study, the previous version was used. There is no validated Polish version of the DC/TMDs so far, therefore, the RDC/TMDs was used. Secondly, the study sample consists of young adult women. We decided to include only women in the presented research because masticatory muscle pain associated with MTrPs is 1.5-2 times more frequent in women than in men. Thus, future research should include the male population with an expanded age range. Thirdly, a generalization of the findings is limited by the short-term follow-up used in the presented study. Therefore, a longer period of follow-up is recommended to determine the long-term effects of the compression technique in patients with masticatory muscle pain. Moreover, in a heterogeneous population of healthy adults, natural variations in age, height, and weight significantly affect the MMO [29]. In the presented study, there were no significant differences in age between the study group and controls. However, weight and height were not included in the comparison. Hence, future research should also include demographic data in this area.