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.


METHODS
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.
Department of Oral Medicine and Oral Diagnosis, School of Dentistry and Dental Research Institute, Seoul National University, Korea.
Seung Jin
SJ
Lee
Willard D
WD
McCall
Young Ku
YK
Kim
Sung Chang
SC
Chung
Jin Woo
JW
Chung
D000328:Adult; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D009465:Neuromuscular Agents / Q000008:administration & dosage*; D017060:Patient Satisfaction; D020186:Sleep Bruxism / Q000188:drug therapy*; D055815:Young Adult
D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A