## 3 Results  
The flowchart of data selection is shown in Figure 1. A total of 357 articles were found in the electronic search. After all titles were checked, 87 duplicates were removed, and 270 articles were selected for abstract reading. Then, the analysis of the abstracts excluded articles that clearly did not satisfy the eligibility criteria. Therefore, 55 full-text articles were identified. Finally, 11 full-text articles satisfied the inclusion criteria. Features of the included studies are reported in Table 1.  
Figure 1: Flow diagram of the selection of the studies (performed according to the PRISMA guidelines). \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Authors** & **Publication Year** & **Study Design** & **No. Patients** & \begin{tabular}{c} **Comparison of** \\ **Interventions** \\ \end{tabular} & **Follow-Up** \\ \hline [PERSON] et al. [23] & 2021 & RCT & 100 & FID vs. SS vs. BoNT-A & 6 months \\ \hline [PERSON] et al. [22] & 2021 & RCT & 40 & \begin{tabular}{c} Occlusal splint \\ vs. BoNT-A \\ \end{tabular} & 6 months \\ \hline [PERSON] et al. [24] & 2021 & RCT & 54 & \begin{tabular}{c} Acupuncture vs. SS \\ vs. BoNT-A \\ \end{tabular} & 1 month \\ \hline [PERSON] et al. [31] & 2020 & RCT & 100 & FID vs. SS vs. BoNT-A & 6 months \\ \hline [PERSON] et al. [25] & 2020 & RCT & 60 & \begin{tabular}{c} Lidocaine vs. SS \\ vs. BoNT-A \\ \end{tabular} & 6 months \\ \hline [PERSON] et al. [32] & 2019 & RCT & 12 & SS vs. BoNT-A & 4 months \\ \hline [PERSON] et al. [26] & 2016 & RCT & 30 & \
\begin{tabular}{c} SS vs. no injection \\ vs. BoNT-A \\ \end{tabular} & 6 months \\ \hline [PERSON] et al. [27] & 2012 & RCT & 30 &
\begin{tabular}{c} Fascial manipulations \\ BoNT-A \\ \end{tabular} & 3 months \\ \hline [PERSON] et al. [29] & 2011 & RCT & 21 & SS vs. BoNT-A & 3 months \\ \hline [PERSON] et al. [33] & 2008 & RCT & 20 & SS vs. BoNT-A & 6 months \\ \hline [PERSON] et al. [28] & 2003 & RCT & 90 & SS vs. BoNT-A & 3 months \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Features of included randomized controlled trials. The included human studies had at least 1 month follow-up, included at least 10 patients treated for TMDs, and evaluated at least one postoperative clinical outcome, such as orofacial pain and/or muscular diseases. [PERSON] et al. [22], comparing the use of BoNT-A and occlusal splints, showed that there was a statistically significant decrease in orofacial pain by visual analogue scale (VAS) during the control period (6 months) after the application of both treatments, though there were no significant differences between these methods. Similarly, [PERSON] et al. [23], comparing BoNT-A and a maxillary flat intraoral device used during sleep, reported that, in contrast to treatment with a flat intraoral device, BoNT-A treatment enhanced psychosocial aspects in patients with masticatory myofascal pain. Similarly, [PERSON] et al. found that acupuncture, saline solution, and BoNT-A all reduced the self-perceived pain in patients with orofacial pain over the course of a month. However, BoNT-A was not superior to acupuncture in terms of pain reduction, but both were superior to saline solution (P.001). In contrast to treatment with a flat intraoral device, BoNT-A treatment enhanced psychosocial aspects in patients with masticatory myofascal pain. Similarly, [PERSON] et al. found that acupuncture, saline solution, and BoNT-A all reduced the self-perceived pain in patients with orofacial pain over the course of a month. However, BoNT-A was not superior to acupuncture in terms of pain reduction, but both were superior to saline solution (P.001) [24]. Conversely, [PERSON] et al. [25], reporting a comparative analysis between BoNT-A, saline solution, and lidocaine injections, showed significant differences favoring the BoNT-A group by means of pain intensity reduction on VAS scores, maximum interincisal opening, and right and left lateral and protrusion movements, in comparison to saline solution and lidocaine groups. Apart from that, [PERSON] et al.