A limitation in the conducted studies was the short duration of therapy which women underwent and the small number of therapeutic subgroups. Additionally, no assessment was made on how long the therapeutic effect obtained during the applied treatments was maintained after the end of the treatment cycle. Therefore, the authors see the need to continue the conducted research, focusing on the above limitations.
Non-invasive therapeutic methods play an important role in the treatment of TMDs. In TMDs, where the pain triggering factor is an increased muscle tone, the first treatment should be implemented to eliminate these ailments. At the initial stage of treatment, it is worth using physiotherapeutic methods. Thanks to them, may obtain analgesic and myorelaxing effect. The next step should be to coordinate appropriate dental treatment, i.e. splint therapy [34]. While rehabilitation in the form of splints has an established position in modern dental treatment, the use of physiotherapeutic treatment in patients with TMDs still requires numerous clinical trials to determine their therapeutic effectiveness.
In this research, the authors focused on the assessment of the effectiveness of the manual therapy and physical therapy procedures, and their clinical effectiveness was assessed on the basis of the analysis of non-invasive SEMG of the masseter muscles, the assessment of pain intensity on the NRS scale and the assessment of mandibular mobility.
According to the preliminary examination, patients with pain and limited mobility of the mandible at baseline had statistically significantly higher SEMG values of the masseter muscle compared to the control group (p < 0.00; SEMG RLX right IC95% 23.40-37.48 and left IC95% 35.77–53.43; SEMG MVC right IC95% 218.61-322.35 and left IC95% 291.29-377.17) before the start of physiotherapy. On the other hand, all assessed ranges of mandibular mobility (opening, lateral movements to the right and left) were significantly smaller in the study group (p < 0.00). When characterizing pain intensity in the study group, its mean value was 6 NRS (moderate pain). As shown by other authors, increased muscle tension affects the range of mobility of the temporomandibular joints and contributes to the occurrence of pain [38].
According to the studies conducted by the authors, MT turned out to be the most effective therapeutic method in terms of analgesic and myorelaxation. In patients who underwent physical therapy procedures, no clinically significant difference in the assessed parameters was found. This data may indicate the superiority of manual methods over physical methods in patients with TMDs disorders. Hence, in the opinion of the authors, physical methods should only complement the therapy in manual work with TMD patients. Particularly noteworthy is the fact that after the 6th MT treatment the patients had complete pain relief (0 NRS) or the pain remained at the level of 1 on the NRS scale. For comparison, in patients who underwent physical procedures, the intensity of pain on the 6th day of therapy was: MS (NRS 7), MLA (NRS 6), and MLE (NRS 5), respectively. According to studies by Urbański et al., the use of MT treatments (PIR or MR- myofascial release treatment) in patients with TMDs contributes to a decrease in the bioelectric activity of the masticatory muscles and a decrease in the intensity of pain in the VAS scale [39]. Manzotti et al. assessed the therapeutic effectiveness of manipulative osteopathic treatment on the activity of the muscles of the stomatognathic apparatus, according to their research, the above form of therapy significantly influences the bioelectric activity of the masseter muscles compared to the placebo group [40]. Rodrigues D et al., when assessing the impact of tens treatments on the bioelectric activity of masticatory muscles and pain, observed that the application of tens effectively reduces pain, but does not act homogeneously on the characteristics of electrical activity of the assessed muscles [41]. Similarly to the above, the effectiveness of the analgesic effect of physical therapy was described by Del Vecchio et al., indicating the effectiveness of home treatment of pain associated with TMDs using the method of low energy laser therapy (LLLT) [42]. Chellappa et al. investigated that tens and LLLT therapy improves the range of TMJ movement and relieves pain in both therapies with the predominant effectiveness of LLLT therapy [43]. Sancakli et al. assessed the effectiveness of the use of a low-level laser (LLL) on the points of greatest pain in patients with chronic pain in the masticatory muscles. According to their research, as a result of the applied physical therapy, there was a statistically significant reduction in the value of PPT of muscles, the number of muscles without pain on palpation increased significantly, and the range of mandibular movements improved. In contrast, the placebo group showed no statistically significant difference in any of the measured values [44].
Analyzing the above data and our own results, it can be stated with great caution that treatments in the field of physical therapy reduce the intensity of the perceived pain, and thus improve the range of mandibular mobility, but their effect does not affect the bioelectrical activity of the muscle. On the other hand, the effect of MT, due to its deeper impact on soft tissues, in addition to improving the TMJ function and analgesic effect, leads to changes in the SEMG parameters.
The lack of systematic knowledge about the effectiveness of MT in people with TMDs prompted Calixtre et al. [45] to conduct a systematic review of the scientific evidence regarding the isolated effect of MT on the improvement of maximum mouth opening and pain in patients with TMD symptoms. According to it, there is very different evidence that MT (depending on the technique) relieves pain, reduces the pressure threshold of the tissue, and affects the range of motion of TMJ in people with TMD symptoms. According to the analysis, myofascial relaxation and massage techniques applied to the masticatory muscles are more effective than control, but as effective as botulinum toxin injections. Techniques for manipulating or mobilizing the upper cervical spine are more effective than control, while chest manipulations are not [45]. The difficulty in comparing the available research results with the results of the authors of the study is caused by the lack of standardized assessments and protocols for physiotherapeutic treatment, and this filling of the gap would significantly strengthen the clinical significance of the conducted research.
A very valuable meta-analysis was performed by Zangh et al. in which they compared the impact of therapeutic exercises and bite-bar therapy on pain and mobility in people with painful TMJ disorders. The conducted analysis did not show high-quality evidence to distinguish clinical efficacy between occlusal splint therapy and exercise therapy in patients with painful TMD and limited mandibular mobility. Hence, it seems necessary to implement more randomized, controlled trials comparing the effects of TMJ exercise and treatment of occlusal splints [46].
When analyzing the TMJ mobility parameter in the conducted studies, also in this case the most effective form of therapy turned out to be the MT. The statistical analysis shows that 10 MT treatments lead to a significant improvement in TMDs function, which is confirmed by the obtained parameters of MMO (MT = 42.96 mm; 95%CI 42.58–43.34) and lateral movements of the mandible (LMR = 8.50 mm, 95%CI 8.09-8.91and LML = 8.63 mm, 95% CI 8.14–8.86). In patients undergoing physical procedures after 10 days of treatment, no clinically significant therapeutic effects were observed, i.e. MS (MMO = 36.73, 95%CI 36.06–37.39;
LMR = 6.27mm, 95%CI 5.95–6.58 and LRL = 6.19.mm, 95%CI 5.80–6.58) MLE (MMO = 37.42 mm, 95%CI 36.81–38.03; LMR = 6.88 mm, 95%CI 6.46-7.31and LRL = 6.62 mm, 95%CI 6.18–7.05) MLA (MMO = 37.38 mm, 95%CI 36.68–38.08; LMR = 6.58 mm, 95%CI 6.29–6.86 and LRL = 6.00mm, 95%CI 5.76–6.24). Similar results were obtained by Tuncer et al., who showed that a more effective therapeutic effect in the treatment of TMJ dysfunction is achieved through MT, combined with home physical therapy than through monotherapy (physical therapy) [47].
From the clinical point of view, the research conducted by the authors shows the legitimacy of implementing manual therapy treatments into everyday physiotherapeutic practice in patients with TMDs. As can be seen from the analysis of the change in the values of the parameters studied during the study, obtained by subtracting the result after the 10th treatment from the result before the first procedure, from a clinical point of view, there was a significant saucer of pain intensity (-6NRS) and bioelectrical function of the masseter muscle (%MVC P=-6,4/L=-9,76) and an increase in the extent of mandibular visitation (7mm) in the TM group. No clinically significant differences in the parameters studied were observed in any group where physical treatments were applied.
The randomized control study conducted by the authors clearly shows the significant impact of manual therapy procedures on the improvement of the mobility of the temporomandibular joints, reduction of muscle tension and pain in people with TMDs. In everyday physiotherapeutic practice, it can be observed more and more often that manual therapy procedures have started to replace physiotherapeutic procedures to a large extent. Despite the higher cost of manual procedures, both therapists and patients observe better therapeutic effects after using MT compared to physical therapy. Therefore, it seems reasonable to implement manual therapy supplemented with physiotherapy treatments in patients with TMDs. The conducted studies additionally highlighted the need to continue research on this subject, as the available scientific literature contains a small number of randomized, control studies comparing the effectiveness of physical and manual therapies in patients with TMDs. Summing up, as shown by the authors' clinical experience, the cooperation between the TMDs treatment team (including dentist, neurologist, ENT specialist) and a dental physiotherapist should become the ‘gold standard’ in modern dentistry.
As it results from the studies presented above, physiotherapy should be an integral part of the interdisciplinary treatment of patients with painful TMD. By comparing the effectiveness of physical treatments and manual therapy, it was observed that MT is definitely more effective. Manual therapy showed a more favorable analgesic and myorelaxing effect, thus contributing to the improvement of the mobility of the temporomandibular joints. Therefore, it can be concluded with great caution that in patients with TMD, the superior form of therapy should be TM supplemented with physical treatments such as magnetoledotherapy and magnetolaserotherapy.