Efficacy of Botulinum Toxin Versus Lidocaine in Treating Masticatory Myofascial Face Pain Using Ultrasound and EMG Guided Techniques
Condition: Face Pain
MeSH terms: Facial Pain
Intervention: lidocaine; chemodenervation
Intervention description: 1cc 1%; botulinum toxin
Intervention MeSH terms: Lidocaine
Phase: Phase 4
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Enrollment: 17.0
Sex: All
Minimum age: 18 Years
Maximum age: 65 Years
Healthy volunteers: Accepts Healthy Volunteers
Keywords: Bruxism; Myofascial pain; EMG; Ultrasound; Masticatory myofascial face pain from bruxism and clenching

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 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.
    

Eligibility criteria:

        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.