Effect of experimental chewing on masticatory muscle pain onset.

Objectives: To evaluate the effect of a chewing exercise on pain intensity and pressure-pain threshold in patients with myofascial pain.

Methods: Twenty-nine consecutive women diagnosed with myofascial pain (MFP) according to the Research Diagnostic Criteria comprised the experimental group and 15 healthy age-matched female were used as controls. Subjects were asked to chew a gum stick for 9 min and to stay at rest for another 9 min afterwards.