J Calif Dent Assoc. 2006 Aug;34(8):625-30.

Orofacial muscle pain: new advances in concept and therapy.

  • Lotaif AC, Mitrirattanakul S, Clark GT.

Clinical Dentistry Orofacial Pain and Oral Medicine Center, Division of Diagnostic Sciences University of Southern California, School of Dentistry, Los Angeles 90089, USA.

This manuscript focuses on chronic myogenous pains affecting the masticatory muscles. The differentiation of myogenous masticatory pain into subcategories is proposed by separating myogenous pains according to their location and anatomic extent. Focal myalgia, regional myalgia, myofascial pain, and fibromyalgia are classified based on specific historical and clinical examination criteria.

The probable mechanisms underlying chronic myogenous pains and trigger points phenomena are discussed.

Treatment options of the myogenous masticatory pain conditions including physical medicine modalities, as well as several types of pharmacologic agents, are presented.

Acupunct Med. 2005 Sep;23(3):121-34.

A review of myofascial pain and fibromyalgia--factors that promote their persistence.

  • Gerwin RD.

Chronic muscle pain (myalgia) is a common problem throughout the world. Seemingly simple, it is actually a difficult problem for the clinician interested in determining the aetiology of the pain, as well as in managing the pain.

The two common muscle pain conditions are fibromyalgia and myofascial pain syndrome.

Fibromyalgia is a chronic, widespread muscle tenderness syndrome, associated with central sensitisation. It is often accompanied by chronic sleep disturbance and fatigue, visceral pain syndromes like irritable bowel syndrome and interstitial cystitis.

Myofascial pain syndrome is an overuse or muscle stress syndrome characterised by the presence of trigger points in muscle.

The problem these syndromes pose lies not in making the diagnosis of muscle pain. Rather, it is the need to identify the underlying cause(s) of persistent or chronic muscle pain in order to develop a specific treatment plan.

Chronic myalgia may not improve until the underlying precipitating or perpetuating factor(s) are themselves managed. Precipitating or perpetuating causes of chronic myalgia include structural or mechanical causes like scoliosis, localised joint hypomobility, or generalised or local joint laxity; and metabolic factors like depleted tissue iron stores, hypothyroidism or Vitamin D deficiency.

Sometimes, correction of an underlying cause of myalgia is all that is needed to resolve the condition.

J Oral Rehabil. 2006 Oct;33(10):713-21.

Treatment outcome of short- and long-term appliance therapy in patients with TMD of myogenous origin and tension-type headache.

  • Ekberg EC, Nilner M.

Department of Stomatognathic Physiology, Faculty of Odontology, Malmo University, Malmo, Sweden.

The aim was to compare the short- and long-term effect of a stabilization appliance with a control appliance in myofascial pain patients suffering from episodic or chronic tension-type headache.

Sixty patients (mean age 29 +/- 12 years) with temporomandibular disorders (TMD) of myogenous origin and headache were studied in this prospective controlled study. Seventy-seven per cent of the patients reported episodic and 23% chronic tension-type headache at the start of the study. The 60 patients were randomly assigned to a treatment group (stabilization appliance) or to a control group (control appliance).

The patients were interviewed regarding symptoms of headache and myofascial pain and clinically examined for masticatory muscle tenderness.

At the 10-week and the 6- and 12-month evaluations of appliance therapy, the treatment outcome of tension-type headache was studied.

At the 10-week evaluation, 17 patients dropped-out from the control group by requesting another appliance and receiving a stabilization appliance. Another patient in the control group dropped out later during the trial. In an intent-to-treat analysis, significant differences in improvement of headache between treatment and control groups were found at the follow-ups.

A 30% reduction of muscles tender to palpation correlated significantly to improvement of headache at all follow-ups.

The stabilization appliance seems to have a positive effect on tension-type headache, both in a short- and in a long-term perspective in patients with TMD with pain of myogenous origin.