Botulinumtoxin A as a Treatment for Myalgia and Myofacial Pain in Patient With Temporomandibulardisorders

The primary goal with this study is to expand treatment modalities for patient with myogenous TMD, and to develop clinical protocols with adequate doses for myogenous TMD. A secondary goal is to study if there are differences in treatment effect between sub-groups of myogenous TMD for more personalised pain-treatment.

Hypothesis The investigators hypothesis is that application of BTX into the masseter and temporalis muscle will reduce pain and increase quality of life in patients with myogenous TMD, and that the reduction of pain is only to a certain degree due to the dose. High doses of BTX does not necessarily entail increased reduction of pain or better quality of life. The investigators also hypotheses that the effect may differ in sub-groups of myogenous TMD.

Inclusion criteria

• Has given a written consent
• Diagnose of myalgia, myofacial pain or myofascial pain with referred pain according
• Average pain due to NRS ≥ 3 for more than three months
• Palpationpain in masseter or temporalis.
• Eventual treatment for orofacial pain > three months ago.
• Adequate contraceptives and a negative pregnancy test.

Patients will still be included even if they have one or more co-diagnoses

• Discdisplacement with or without reduction
• Degenerative joint disease
• Arthralgia

Exclusion criteria

• Treatment with BTX during the last 12 months
• Treatment for orofacial pain within the last 3 months.
• Systemic inflammatory diseases (rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis)
• Widespread pain e.g., fibromyalgia
• Neuropathic pain
• Neurologic disease (myasthenia gravis)
• Pain of dental origin
• Use of muscle relaxants, or aminoglycoside antibiotics
• Pregnancy or nursing
• Hypersensitivity to BTX
• Neuropsychiatric conditions.
• Difficulties understanding the Swedish language