Botulinum toxin type A and acupuncture for masticatory myofascial pain: a randomized clinical trial.

BACKGROUND

BoNT-A has been widely used for TMD therapy. However, the potential benefits compared to dry needling techniques are not clear.

OBJECTIVE

this study aimed to compare the immediate effects of botulinum toxin type A (BoNT-A) injections and Acupuncture in myofascial temporomandibular disorders (TMD) patients.

METHODOLOGY

54 women were divided into three groups (n=18). AC patients received four sessions of traditional acupuncture, being one session/week during 20-min. BoNT-A patients were bilaterally injected with 30U and 10U in masseter and anterior temporal muscles, respectively. Moreover, a control group received saline solution (SS) in the same muscles. Self-perceived pain was assessed by visual analog scale, while pressure pain threshold (PPT) was verified by a digital algometer. Electromyographic evaluations (EMG) of anterior temporal and masseter muscles were also measured. All variables were assessed before and 1-month after therapies. The mixed-design two-way repeated measures ANOVA and Tukey's post-hoc tests were used for analysis, considering a=0.05.

RESULTS

Self-perceived pain decreased in all groups after one month of therapy (P<.001). BoNT-A was not better than AC in pain reduction (P=0.05), but both therapies were more effective in reducing pain than SS (P<0.05). BoNT-A was the only treatment able to improve PPT values (P<0.05); however, a severe decrease of EMG activity was also found in this group, which is considered an adverse effect.

CONCLUSION

after one month of follow-up, all therapies reduced the self-perceived pain in myofascial TMD patients, but only BoNT-A enhanced PPT yet decreased EMG.