Efficacy of Botulinum Toxin Versus Lidocaine in Treating Masticatory Myofascial Face Pain Using Ultrasound and EMG Guided Techniques

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 pterygoid muscles, important masticatory muscles that is often hyperactive in masticatory myofacial pain was not injected due to lack of palpable surface landmarks. Ultrasound and electromyography (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 pterygoid. 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.

Study Overview

• Status: Terminated
• Conditions: Face Pain
• Intervention / Treatment: Drug: lidocaine; Drug: chemodenervation

• Study Type: Interventional
• Enrollment (Actual): 17
• Phase: Phase 4

Contacts and Locations

Study Locations

• United States
  • California
    • Los Angeles, California, United States, 90024
      • Westwood Associates

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Subjects are to have identifiable painful myofascial trigger points in the masseter, temporalis, and medial and lateral pterygoid muscles.
• Subjects will be examined by the principle investigators to determine if the individual is a suitable candidate for the study, based on active trigger points and willingness to participate in the study

Exclusion Criteria:

• Pregnant woman will be excluded from participation as potential risk is noted in product label indications. Individuals over the age of 65 will be excluded per product label indications that reflect lack of data in individuals over age 65.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Lidocaine; lidocaine injection group	Drug: lidocaine; 1cc 1%
Experimental: Botulinum	Drug: chemodenervation; botulinum toxin

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Clinical Response as Assessed by >20% Change From Baseline in the Jaw Functional Limitation Scale (JFLS) Global Score	The JFLS contains 20 items that measure limitations across mastication, vertical jaw mobility, and verbal/emotional expression rated on a 0-10 scale where 0 = "no limitation" and 10 = "severe limitation."	4 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Clinical Response as Assessed by >20% Change From Baseline in the Jaw Functional Limitation Scale (JFLS) Global Score	The JFLS contains 20 items that measure limitations across mastication, vertical jaw mobility, and verbal/emotional expression rated on a 0-10 scale where 0 = "no limitation" and 10 = "severe limitation."	6 weeks
Clinical Response as Assessed by >20% Change From Baseline in the Pressure Pain Threshold	measurements were obtained by placing examiner's index finger of the examiner on the area of the trigger point (hyperirritable areas on skeletal muscle with palpable taut bands of muscle fibers) and exerting pressure until there was whitening of the nail bed. Pressure pain levels were rated subjectively by the participant and coded numerically as mild (1), moderate (2) to severe (3).	baseline, 4 months
Clinical Response as Assessed by >20% Change From Baseline in Jaw Opening	maximum mandibular range of motion scores (measured as the maximum interincisal distance and compensating for occlusion)	baseline, 4 months

Collaborators and Investigators

• Sponsor: University of California, Los Angeles
• Investigators: Principal Investigator: Marisa Chang, M.D., University of California, Los Angeles

Study record dates

Study Major Dates

• Study Start: October 1, 2009
• Primary Completion (Actual): October 1, 2010
• Study Completion (Actual): October 1, 2010

Study Registration Dates

• First Submitted: October 8, 2009
• First Submitted That Met QC Criteria: October 8, 2009
• First Posted (Estimate): October 9, 2009

Study Record Updates

• Last Update Posted (Estimate): December 29, 2016
• Last Update Submitted That Met QC Criteria: November 2, 2016
• Last Verified: November 1, 2016

More Information

Terms related to this study

• Keywords: Ultrasound; Myofascial pain; EMG; Bruxism; Masticatory myofascial face pain from bruxism and clenching
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Facial Pain; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Anti-Arrhythmia Agents; Central Nervous System Depressants; Peripheral Nervous System Agents; Sensory System Agents; Anesthetics; Membrane Transport Modulators; Anesthetics, Local; Voltage-Gated Sodium Channel Blockers; Sodium Channel Blockers; Lidocaine
• Other Study ID Numbers: 8295968