BACKGROUND AND OBJECTIVES: Temporomandibular disorders (TMD) involve a set of craniofacial changes, which may involve temporomandibular joint (TMJ), jaw muscles and/or associated structures. Muscle TMD is the most frequent, and one of its subtypes is myofascial pain. Botulinum toxin type A (BoNT A), has been studied to control pain, including myofascial pain, and is related to pain relief mechanisms not only in neuromuscular junction receptors. This study aimed at evaluating articles addressing BoNT A to treat jaw muscles myofascial pain. CONTENTS: Pubmed, LILACS and BVS databases were queried from 2000 to April 2012, crossing the following keywords: botulinum toxin type A, myofascial pain syndromes, facial pain, temporomandibular joint disorder syndrome, trigger-points, bruxism, temporomandibular joint, masseter muscle and temporalis muscle. Inclusion criteria were randomized double blind or blind studies, with 10 or more participants, with randomized methodological aspects, relating the use of botulinum toxin for jaw muscles TMD myofascial pain, more specifically masseter and temporalis muscles, and limited to the English language. Six articles were found and included in this study. CONCLUSION: BoNT A was not more effective to treat myofascial pain than established conventional treatments. Because there are many uncontrolled variables in the few related studies, more studies with judicious methodologies are needed to make feasible its use in patients refractory to pain and previously submitted to conservative treatments.
Botulinum toxin type A; Facial pain; Myofascial pain syndromes; temporomandibular joint disorder syndrome
