This study compared myofascial pain of the masticatory muscles
to fibromyalgia. Study data show that, in both myofascial pain
and fibromyalgia patients, facial pain intensity and its daily
pattern and effect on quality of life are very similar.
This indicates that fibromyalgia should be included in the
differential diagnosis for myofascial pain of the masticatory
muscles. However, with the higher prevalence of neurologic and
gastrointestinal symptoms, and the stronger words used to
describe the affective dimension of pain, it is apparent that
fibromyalgia may be a more debilitating condition than
myofascial pain of the masticatory muscles.
Since the intensity of facial pain was strongly and significantly
correlated to the body-pain index in fibromyalgia but not in
myofascial pain patients, it can be concluded that facial pain
may be part of the clinical manifestations of fibromyalgia,
but it is unlikely to be related to body pain in myofascial
pain patients. On the other hand, while body pain is episodic
in most myofascial pain patients, it is constant and more
severe in the majority of fibromyalgia patients.
This difference in the pain patterns suggests that body pain in
fibromyalgia and myofascial pain could have different
etiologies. The lack of correlation between the intensity of
pain and the length of time since onset also supports the
concept that myofascial pain of the masticatory muscles and
fibromyalgia are unlikely to be progressive disorders.