A recent study conducted at the Tokyo Medical and Dental University found that therapeutic exercise brings earlier recovery of jaw function compared with splints!
Of the various conservative treatment modalities available for temporomandibular disorders, we believe that therapeutic exercise has a good prognosis, especially for anterior disc displacement without reduction. Since its effectiveness has not been extensively evaluated, we conducted a comparative study to verify the hypothesis that treatment efficacy would not differ for exercise and occlusal splints. Fifty-two individuals with anterior disc displacement without reduction were randomly assigned to a splint or a joint mobilization self-exercise treatment group. Four outcome variables were evaluated: (i) maximum mouth-opening range without and (ii) with pain, (iii) current maximum daily pain intensity, and (iv) limitation of daily functions. All outcome variables significantly improved after 8 weeks of treatment in both groups. In particular, the mouth opening range increased more in the exercise group than in the splint group. This result demonstrates that therapeutic exercise brings earlier recovery of jaw function compared with splints.
All participants received a verbal explanation of their pathological conditions regarding jaw function based on x-ray and MRI findings, and a general self-care protocol such as good posture, soft diet, teeth apart, etc.
Participants in the splint group wore a maxillary stabilization appliance while sleeping at night. The splint was 1.5-mm-thick hard, clear acrylic sheet that was vacuum-adapted to the maxillary cast. The splint was adjusted to ensure occlusal contact of all mandibular teeth in centric relation and mandibular canine guidance in eccentric movement.
In the exercise group, participants performed manual jaw-opening exercises by themselves, according to the following protocol: As a warm-up, the individual repeated small mouth-opening and closing movements several times. Then, the individual placed his/her fingertips on the edge of the mandibular anterior teeth and slowly pulled the mandible down until pain occurred on the TMJ-affected side. This mouth-opening position was held for 30 sec. Three cycles of this stretching movement were defined as a single set. The participant performed 4 sets per day, one after each meal and one while bathing.
All participants in both groups were prescribed a non-steroidal anti-inflammatory drug (Amfenac sodiu, Fenazox, Meiji Sika Co., Tokyo, Japan; 150 mg) 3 times every day, and were followed up at 4 and 8 weeks after the start of treatment. No significant adverse effect was reported resulting from either treatment.