EffectofTherapeuticJawExercisesintheTreatmentofMasticatoryMyofascialPain:ARandomizedControlledStudy

Masticatory myofascial pain is one of the most common forms of temporomandibular disorder (TMD), causing significant discomfort, limited jaw function, and associated symptoms like tension-type headaches. Patients often seek relief through various conservative treatments, with stabilization appliances (occlusal splints) being among the most widely used and studied interventions. However, therapeutic jaw exercises represent another conservative approach that may offer advantages in terms of cost, convenience, and patient empowerment. Despite some prior research suggesting benefits of jaw exercises, the evidence base remained limited by small sample sizes and few randomized controlled trials.

This study aimed to address this gap by directly comparing jaw exercises to both the gold-standard stabilization appliance and a no-treatment control group, while also examining cost-effectiveness—a practical consideration for both patients and healthcare systems.

The researchers conducted a three-arm randomized controlled trial at a specialist clinic in Uppsala, Sweden. They recruited 97 patients who met strict inclusion criteria: myofascial pain with or without limited mouth opening according to the Research Diagnostic Criteria for TMD (RDC/TMD), pain intensity greater than 40 mm on a 0-100 mm visual analog scale, symptoms lasting at least 6 months, and age 18 or older. Patients were randomly assigned to one of three groups: therapeutic jaw exercises (35 patients), hard acrylic stabilization appliance (33 patients), or no treatment/waiting list control (29 patients). The jaw exercise program included relaxation exercises, free mandibular movements, resisted movements, and stretching, to be performed three times daily.

The stabilization appliance group received a custom-made hard acrylic device adjusted for optimal stability, to be worn nightly. The no-treatment group returned to the waiting list after initial examination. All patients were evaluated after 3 months using validated instruments measuring pain intensity at rest and during jaw movement, global improvement (PGIC), depression and anxiety (HADS), jaw function (JFLS-20), analgesic consumption, and headache frequency. Treatment cost-effectiveness was measured by number of appointments and total treatment time.

A research assistant blinded to treatment group conducted follow-up evaluations.

Pain intensity during jaw movement decreased significantly more in the jaw exercise group compared to the no-treatment group (P < .001), with no statistically significant difference between the jaw exercise and stabilization appliance groups. In the jaw exercise group, the overall mean reduction of pain intensity was 67% at rest and 62% during jaw movement, compared to 55% and 44% respectively in the stabilization appliance group. However, these between-group differences did not reach statistical significance. In per-protocol analysis, significantly more patients in the jaw exercise group achieved 30% and 50% pain reductions compared to no treatment, while the stabilization appliance group showed significant differences only at the 50% level.

The number needed to treat for 50% pain reduction was 2.2 for jaw exercises and 2.9 for stabilization appliances. Both treatment groups reported greater global improvement on the PGIC compared to no treatment (P < .001). The jaw exercise group showed significant reductions in headache frequency (P = .028), analgesic consumption (P = .007), and jaw functional limitation scores (P = .008) compared to no treatment—improvements not consistently seen with the stabilization appliance. Importantly, jaw exercises required significantly fewer appointments (mean 3 vs 4, P < .001) and less treatment time (mean 24 minutes vs 47 minutes, P < .001) than the stabilization appliance, making them more cost-effective.

Patient adherence was notably poor in the jaw exercise group: only 4 of 28 patients (14%) performed exercises as recommended (three times daily), with 10 doing them 1-2 times daily and 14 even less frequently. Despite this low adherence, clinical benefits were still observed.

This study provides meaningful evidence that therapeutic jaw exercises are an effective, low-cost treatment option for masticatory myofascial pain. For patients, this suggests that simple, self-directed exercises can reduce jaw pain, decrease headaches, and lessen reliance on pain medications—without the expense and dental visits required for a stabilization appliance. The finding that benefits occurred even with poor adherence raises interesting questions about optimal dosing; perhaps less frequent exercise than traditionally recommended may still be therapeutic. For clinicians, jaw exercises should be considered a first-line or co-treatment option, particularly for cost-conscious patients or those who cannot tolerate appliances.

However, the high dropout rate in the exercise group (20% vs lower rates in other groups) and generally poor adherence suggest that clinicians need to develop better strategies to support patient compliance—perhaps through apps, reminders, or simplified protocols. The lack of significant difference between jaw exercises and stabilization appliances, combined with the cost advantage, challenges the routine use of appliances as first-line therapy. The study's failure to reach its target enrollment (97 vs 174 planned) means it may have been underpowered to detect meaningful differences between the two active treatments; indeed, post-hoc analysis suggested 153 patients would have been needed for this comparison. Future research should explore optimal exercise frequency, strategies to improve adherence, and longer-term outcomes beyond 3 months.