Complete dentures with sliding plates in edentulous: electromyographic study

Objectives: this work was performed with the purpose of investigating the electromyographic activity (EMG) of the anterior temporalis and masseter muscles in edentulous individuals with temporomandibular disorder (TMD), before and after using sliding plates on complete dentures in mastication and maximal clenching. The patients were edentulous at last ten years. Methods: the EMG recordings were made before the insertion of the dentures (0 month) and also after using the sliding plates at the 4th month, 9th month, and 12th month, using a computerized electromyography.The electromyographic (EMG) evaluations of the muscles were perfomed under the following clinical conditions: habitual mastication with hyperboloid (M1), rigth molar mastication with hyperboloid (M2), left molar mastication with hyperboloid (M3), maximal clenching with dentures (C1), maximal clenching without dentures (C2). Results: the results were submitted to variance analysis (mastication) and student t test (maximal clenching). Conclusions: In mastication - the EMG of massater muscle was significantly higher than temporalis (p<0,01); in M2 the EMG of the rigth side was significantly higher than the left side (p<0,01); in M3 the EMG of the left side was significantly higher than the right side (p<0,01); there were no significant differences between periods of evaluation. In maximal clenching - in C1 there were no significant differences between muscles, sides, and periods of evaluation; in C2, the EMG of the muscles increased significantly after using the sliding plates (p<0,05); the EMG of the temporalis muscle was significantly higher than masseter(p<0,01); there were no significant differences between sides