This study aimed to evaluate the electromyographic activity of the
orbicularis oris muscle in patients using clinically inadequate
conventional dentures before and after the insertion of clinically
acceptable new convencional denture. Six patients, using inadequate
dentures, were asked to pronounce the syllables PAH, BAH, MAH, SAH,
FAH, VAH, MEE and the word MISSISSIPI. During this activity, we
analyzed the Electromyographic activity of the orbicularis oris muscle.
This was done before and after changing the inadequate denture for a
acceptable new denture. A K6-I EMG Light Channel Surface
Electromyograph was used (Myo-tronics Co). Results were analyzed by
repeated measures ANOVA, with 3 sources of variation (Syllables,
Muscles, and Clinical Conditions). ANOVA revealed higher
electromyographic readings in the mandibular fascicle of the orbicular
oris muscle, as compared to those of the maxillary fascicle (F = 79.02;
P<0.01). The comparison regarding clinical conditions indicated
higher electromyographic values after insertion of acceptable new
denture (F= 32.64; P<0.01). Clinical condition after the
implantation of a new well-adapted complete denture revealed higher
electromyographic activity levels than those measured with the use of
maladapted complete dentures
