Effect of Botulinum Toxin Injection on Nocturnal Bruxism: A Randomized Controlled Trial.

Author(s): Lee SJ, McCall WD Jr, Kim YK, Chung SC, Chung JW

Affiliation(s): From the Department of Oral Medicine and Oral Diagnosis (SJL, YKK, SCC, JWC), School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Korea; and Department of Oral Diagnostic Sciences (WDM), School of Dental Medicine, University at Buffalo, Buffalo, New York.

Publication date & source: 2009-09-26, Am J Phys Med Rehabil., [Epub ahead of print]

Publication type:

Lee SJ, McCall WD, Jr., Kim YK, Chung SC, Chung JW: Effect of botulinum toxin injection on nocturnal bruxism: A randomized controlled trial. OBJECTIVE:: To evaluate the effect of botulinum toxin type A on nocturnal bruxism. DESIGN:: Twelve subjects reporting nocturnal bruxism were recruited for a double-blind, randomized clinical trial. Six bruxers were injected with botulinum toxin in both masseters, and six with saline. Nocturnal electromyographic activity was recorded in the subject's natural sleeping environment from masseter and temporalis muscles before injection, and 4, 8, and 12 wks after injection and then used to calculate bruxism events. Bruxism symptoms were investigated using questionnaires. RESULTS:: Bruxism events in the masseter muscle decreased significantly in the botulinum toxin injection group (P = 0.027). In the temporalis muscle, bruxism events did not differ between groups or among times. Subjective bruxism symptoms decreased in both groups after injection (P < 0.001). CONCLUSIONS:: Our results suggest that botulinum toxin injection reduced the number of bruxism events, most likely mediated its effect through a decrease in muscle activity rather than the central nervous system. We controlled for placebo effects by randomizing the interventions between groups, obtaining subjective and objective outcome measures, using the temporalis muscle as a control, and collecting data at three postinjection times. Our controlled study supports the use of botulinum toxin injection as an effective treatment for nocturnal bruxism.