Immediate curative effects of exercise therapy in patients with myalgia of the masticatory muscles

Exercise therapy is occasionally considered as an initial treatment for temporomandibular disorders. However, pain can be exacerbated during exercise therapy.

To investigate the immediate curative effects of exercise therapy in patients with masticatory muscle myalgia.

Fifty-nine patients with masticatory muscle myalgia were included. Therapists performed exercise therapy (stretched the painful masseter and/or cervical muscles along the direction of muscle contraction) in 10 rounds of traction, each lasting 10 s. The patient's pain-free maximum mouth opening distance and degree of pain (VAS value) before and immediately after exercise therapy were compared using the Wilcoxon signed-rank test. The Mann-Whitney U test was used for the subgroup comparisons.

Mouth opening increased from 41 (IQR 38-43) to 46 (IQR 43-48) mm and pain alleviation from 48 (IQR 31-56) to 21 (IQR 10-56) immediately following exercise therapy (p < .001 for both). None of the patients experienced pain exacerbation or reduction in mouth opening post-exercise. No difference in mouth opening distance changes according to sex, painful side, painful site and therapist were observed (p > .05 for all). Pain reduction was greater in patients with unilateral pain (26, IQR 12-39) than those with bilateral (13, IQR 5-25) (p = .019). There were no differences in the change in the degree of pain according to sex, painful site and therapist (p > .05 for all).

Exercise therapy immediately enlarged the mouth opening distance and reduced myalgia; therefore, it could be helpful in managing masticatory muscle myalgia.