Pulsed Radiofrequency As A Treatment For Mastecatory Muscle Pain In Temporomandibular Disorder Patients

The temporomandibular joint is formed by the mandibular condyle inserting into the mandibular fossa of the temporal bone. Muscles of mastication are primarily responsible for the movement of this joint. Its functionality may be affected by different disorders that are characterized by craniofacial pain involving the joint, masticatory muscles, or muscle innervations of the head and neck. These are known as temporomandibular disorders (TMD). It affects 10% to 15% of adults, but only 5% seek treatment. The incidence of TMD peaks from 20 to 50 years of age and are more common in female population.

TMD is categorized as intra-articular (within the joint) or extra-articular (involving the surrounding musculature). Musculoskeletal conditions (myofascial pain disorder) are the most frequent cause of TMD, accounting for at least 50% of cases. Thus, musculoskeletal conditions associated with TMD include spasm and/or tenderness to palpation of the masseter, temporalis, and/or pterygoid muscles.

Etiology of TMD is multifactorial. Factors consistently associated with TMD include other pain conditions, fibromyalgia, autoimmune disorders, sleep apnea and psychiatric illness. According to the literature, there is 1.8-fold increase in myofascial pain in people with anxiety.

It is important to mention that patients with TMD present with an increase risk to develop chronic and intense headaches. The relationship between chronic TMD and various headaches could be due to similarity in the pathophysiology of both diseases.4-6 Studies suggest, that the trigeminal nucleus contribute to central sensitization associated to interference in descending modulation, and could produce the amplification of pain in this region.

Treatment for TMD is complicated and requires specific knowledge and exercises to strengthen some groups of muscles and stretch others, occlusal splint therapy, massage, trigger point injections, and pharmacotherapy. Although the management seems difficult, most of the patients experience successful improvement once a proper protocol has been established. Muscle relaxants (baclofen, tizanidin, cyclobenzaprine), nonsteroidal anti-inflammatory drugs (NSAIDS), opioids, anticonvulsants (e.g., gabapentin), ketamine, tricyclic antidepressants (e.g., amitriptyline) and benzodiazepines, have also been used clinically for TMD management, but there is no evidence that supports or refutes the effectiveness of these medications. In some cases where patients present with severe acute pain, or chronic pain secondary to serious TMD, inflammation, or degeneration, minimally invasive and invasive procedures should be considered.