A study published in "PLoS One" depicted that bilateral Botulinum toxin A (BTX-A) injections into the masseter muscle alone and in both the masseter and the temporal muscles seem to have similar clinical performance in the short-term management (up to 120 days) of bruxism when taking into account treatment satisfaction, bite force reduction, and pain relief. Researchers used two protocols of BTX-A injections to assess treatment satisfaction, perception of orofacial pain, and biting force of individuals with bruxism.

In this randomized single-blind clinical trial, two groups of subjects with bilateral orofacial pain of muscle origin and seeking treatment for bruxism were randomly segregated into Group MT and Group M.  Individuals in Group MT received BTX-A injections at the temporal masseter and muscles (three points in each masseter muscle and two points in each temporal muscle, 10 U per point). Individuals in Group M were given BTX-A injections at the masseter muscle alone bilaterally (three points in each muscle, 10 U per point).

Using visual analogue scales (VAS), the pain was assessed.  Estimation of treatment satisfaction, as well as a gnathodynamometer to measure biting force, was done preoperatively and longitudinally at 15, 90, 120, and 180 days. Each group incorporated 10 individuals in the final sample. When compared to baseline, both groups showed pain reduction after 15, 90, 120, and 180 days. However, only at 15, 90, and 120 days, posterior biting force showed a decrease. At 15, 90, 120, and 180 days, both groups reported improved treatment satisfaction. In all assessments and study periods, no variations were noted between the groups. Hence, both BTX-A procedures are equally beneficial for the short-term treatment of bruxism.