Introduction
Botulinum toxin (Botox®) is considered an effective treatment for
nocturnal bruxism when injected into the masseter muscle. Several studies have used different dosages of
Botox for this purpose. The objective was to determine whether 10 MU of
botulinum toxin type A (BTXA)
injections into the masseter muscle could lessen
nocturnal bruxism. Material and methods The sample consisted of 22 patients who suffered from
pain in the masseter muscle and sensitivity of the teeth as a result of its wear due to
nocturnal bruxism. The sample was randomly divided into two groups. The
Botox (BO) group included 11 patients injected with 10 MU of BTXA, and the placebo (PL) group included 11 patients who received a
sham intervention. Pain perception was assessed on visual analogue scales, whereas muscle activity was recorded by electromyography (EMG) to evaluate the effectiveness of this treatment protocol on
nocturnal bruxism. Results A total of 20 patients entered data analysis with one dropout from each group. The differences in the perceived
pain values between the BO and the PL groups before and after the injection were statistically significant (p<0.05). In the BO group, the changes in the perceived
pain values over time were statistically significant (p<0.05). The
pain levels significantly decreased at two weeks, one month, and three months following the injection. However, the levels increased again at the fourth- and sixth-month assessment times with statistically significant differences (p>0.05). The differences in the EMG recorded values were statistically significant between the two groups (p<0.05). Conclusions Within the current study's limitations, injecting 10 MU of BTXA into the masseter muscle reduced muscular activity in this muscle, resulting in decreased
muscle spasms and
pain symptoms associated with
nocturnal bruxism for about three months before symptoms gradually relapsed.