Effects of Jaw-Opening Exercises with/without Pain for Temporomandibular Disorders: A Pilot Randomized Controlled Trial.

This study aimed to evaluate the effects of jaw-opening exercises with and without pain on temporomandibular disorders (TMDs), specifically in relation to pain intensity and range-of-mouth opening in patients with TMDs. Participants were randomly assigned to either the jaw-opening exercise with pain (JE w/pain) or the jaw-opening exercise without pain (JE w/o pain) groups, and each exercise was performed for eight weeks. TMDs pain intensity was assessed using a 100-mm visual analog scale (VAS), and the range-of-mouth opening was evaluated at the baseline (T0), 2 weeks (T1), 4 weeks (T2), and 8 weeks (T3). Of the 61 participants, 57 (JE w/pain group, n = 30; JE w/o pain group, n = 27) were included in the analysis. The range-of-mouth opening and TMDs pain intensity improved from T1 to T3 in both groups. The JE w/pain group showed significant differences at T3 compared to T1 (pain-free unassisted mouth opening, p = 0.006; jaw-opening pain, p = 0.014; chewing pain, p = 0.018). In addition, the JE w/pain group showed significantly greater changes in the maximum unassisted mouth opening at T2 and T3 than the JE w/o pain group (T2, p < 0.001; T3, p = 0.003). Thus, jaw-opening exercises, until the occurrence of pain, may be effective in patients with TMDs.