Abstract
Background: The aim of this study was to investigate the effect of Botulinum toxin-A (BTX-A) injection in lateral pterygoid (LP) muscle and analyze the efficacy of this treatment modality in reducing Temporomandibular disorder (TMD) symptoms. TMD is the main cause of nondental pain in the orofacial area. The most common symptoms of temporomandibular disorder are joints pain and sound and limitation of jaw function. Botulinum toxin (BTX) injection in LP temporarily paralysesis the muscle. BTX injection is considered as a potential treatment for TMD, due to its pain relieving characteristic and its ability to reduce muscle activity. However, these evidences are mostly case series and more studies are required to prove its efficacy. Methods: Thirty-eight patients (19 women and 19 men, mean age: 26.53 years) with painful unilateral temporomandibular joint click and LP muscle tenderness entered the study. They were divided into two groups; one received extraoral Botax injection in LP muscle, and the other was injected by placebo. Pain severity, jaw’s range of movement, click severity and Helkimo-Index, were taken recorded at first and also in follow upin first visit and in one week, one month and three months after intervention. Data were analyzed using Repeated measures ANOVA and t-test.Results: The result showed that click severity was not significantly different between BTX and placebo groups (p=0.07). Pain and Helkimo index were decreased significantly in BTX group (p=0.00 and P=0.006 respectively); however, there was no significant difference when compared between the two groups (P=0.22 and p=1 respectively). There was a significant difference in lateral movements between the groups (p=0.00) but not in protrusion movement (p=0.095).Conclusions: It can be concluded that although some studies state that BTX injection can make the click sound disappear, in this study we did not find a significant difference between two groups. Furthermore, our results showed that click and pain severity were decreased, but the difference was not statistically significant. Therefore, further studies with more dosage of BTX and higher participants seem to be necessary.Trial registration: The local Ethics Committee of Shiraz University of Medical Science approved this research under Ethics code: IR.SUMS.REC. 2018/10/01 and IRCT number: IRCT20130521013406N3.
Injection of botulinum toxin A in lateral pterygoid muscle as a novel method for prevention of traumatic temporomandibular joint ankylosis
