Effects of soft occlusal appliance therapy for patients with masticatory muscle pain

Background: The options for stabilization appliance therapy for masticatory muscle pain include soft occlusal and hard stabilization appliances. A previous study suggested that hard stabilization appliance therapy was effective for patients with local myalgia who developed long facets on their occlusal appliances. The objective of this study was to identify patients in whom a soft occlusal appliance should be used to treat masticatory muscle pain by analyzing the type of muscle pain present and patient factors that influenced the effectiveness of this treatment. Methods: The study included 42 patients diagnosed with local myalgia or myofascial pain according to the Diagnostic Criteria for Temporomandibular Disorders Diagnostic Decision Tree. The analysis of patient factors included variables believed to be associated with temporomandibular disorders. First, a temporary screening appliance was used for 2 weeks to assess each patient for bruxism during sleep. Soft appliance therapy was then started. For each patient, the effectiveness of the appliance was evaluated according to the intensity of tenderness during muscle palpation and the treatment satisfaction score at one month after starting treatment. Results: Data from 37 of the 42 patients were available for analysis. Twenty-five patients reported satisfaction with the appliance. In logistic regression analysis, the odds ratio for reduction of facet length was 1.998. Nineteen patients showed at least a 30% improvement in the visual analog scale score. The odds ratio for local myalgia was 18.148. Conclusion: Soft appliance therapy may be used in patients with local myalgia. Moreover, patients who develop short facets on the appliance surface are likely to be satisfied with soft appliance therapy. Soft appliance therapy may be appropriate for patients with local myalgia who develop short facets on their occlusal appliance.