Efficacy of botulinum toxin in treating myofascial pain in bruxers: a controlled placebo pilot study

Cranio. 2008 Apr;26(2):126-35. doi: 10.1179/crn.2008.017.


The present investigation is a preliminary double-blind, controlled placebo, randomized clinical trial with a six month follow-up period. The study aimed to assess the efficacy of type A botulinum toxin (Botox, Allergan, Inc. Irvine, CA) to treat myofascial pain symptoms and to reduce muscle hyperactivity in bruxers. Twenty patients (ten males, ten females; age range 25-45) with a clinical diagnosis of bruxism and myofascial pain of the masticatory muscles were enrolled in a double-blind, controlled placebo, randomized clinical trial, with a treatment group (ten subjects treated with botulinum toxin injections- BTX-A) and a control group (ten subjects treated with saline placebo injections). A number of objective and subjective clinical parameters (pain at rest and during chewing; mastication efficiency; maximum nonassisted and assisted mouth opening, protrusive and laterotrusive movements; functional limitation during usual jaw movements; subjective efficacy of the treatment; tolerance of the treatment) were assessed at baseline time and at one week, one month, and six months follow-up appointments. Descriptive analysis showed that improvements in both objective (range of mandibular movements) and subjective (pain at rest; pain during chewing) clinical outcome variables were higher in the Botox treated group than in the placebo treated subjects. Patients treated with BTX-A had a higher subjective improvement in their perception of treatment efficacy than the placebo subjects. Differences were not significant in some cases due to the small sample size. Results from the present study supported the efficacy of BTX-A to reduce myofascial pain symptoms in bruxers, and provided pilot data which need to be confirmed by further research using larger samples.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Attitude to Health
  • Botulinum Toxins, Type A / administration & dosage
  • Botulinum Toxins, Type A / therapeutic use*
  • Bruxism / complications*
  • Double-Blind Method
  • Female
  • Follow-Up Studies
  • Humans
  • Injections, Intramuscular
  • Male
  • Masseter Muscle / drug effects
  • Mastication / physiology
  • Middle Aged
  • Neuromuscular Agents / administration & dosage
  • Neuromuscular Agents / therapeutic use*
  • Pain Measurement
  • Patient Satisfaction
  • Pilot Projects
  • Placebos
  • Pterygoid Muscles / drug effects
  • Range of Motion, Articular / physiology
  • Temporal Muscle / drug effects
  • Temporomandibular Joint Dysfunction Syndrome / drug therapy*
  • Temporomandibular Joint Dysfunction Syndrome / etiology
  • Temporomandibular Joint Dysfunction Syndrome / physiopathology
  • Treatment Outcome


  • Neuromuscular Agents
  • Placebos
  • Botulinum Toxins, Type A