Clinical Trials Logo

Clinical Trial Summary

Botulinum toxin-A (BTX-A) prevents the release of acetylcholine in presynaptic terminals of the neuromuscular junction. It has been proposed to be effective in spastic conditions of the head and neck including oromandibular dystonias, bruxism, and muscular hypertrophy (1,2,3,4). However, only one randomized, double-blinded, placebo controlled trial has been completed involving 20 patients demonstrating both objective and subjective improvement in the BTX-A treated group over those treated with saline at one week, one month, and six months (5).

Currently, in most orofacial pain practices, when the diagnosis of masticatory myofascial pain in the head region is made, patients are treated with a standard myofascial protocol. This protocol involves stretching, application of moist heat, spray and stretch, and lidocaine trigger point injections into the masticatory muscles. This is considered the standard of care among most orofacial pain practioners.

There have been no randomized, double-blinded, head-to-head trials comparing BTX-A injections to lidocaine injections in the treatment of masticatory myofacial pain. Moreover, in all studies, muscles were targeted using surface landmarks with no confirmatory tests to guarantee the medication was administered to the intended muscle. In previous studies, the medial and lateral pteryoid muscles, important masticatory muscles that is often hyperactive in masticatory myofacial pain was not injected due to lack of palpable surface landmarks. Ultrasound and EMG guidance will help us locate these muscles.

The purpose of this study is to objectively measure functional improvement in patients with masticatory myofascial pain injected with lidocaine versus BTX-A. A pilot study enrolling 20 patients is proposed. 20 patients will be randomized to receive either BTX-A or lidocaine injections into the bilateral temporalis, masseter, and medial and lateral pteryoid. Objective and subjective clinical parameters will be measured. These include pain at rest and with chewing, maximum non-assisted and assisted mouth opening, protrusive and laterotrusive jaw movements, subjective efficacy of treatment, and side-effects of treatment. Patients will be assessed at baseline, one week, one month, and three months after the procedure.


Clinical Trial Description

n/a


Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Treatment


Related Conditions & MeSH terms


NCT number NCT00992108
Study type Interventional
Source University of California, Los Angeles
Contact Marisa Chang, M.D.
Phone (310)829-5968
Email changmarisa@yahoo.com
Status Not yet recruiting
Phase Phase 4
Start date October 2009
Completion date October 2010

See also
  Status Clinical Trial Phase
Completed NCT05416788 - Effect of Cervical Manipulation on Mouth Opening N/A