Electromyographic assessment of cantilever extension of bar retaining mandibular complete overdenture

Abstract

Ten patients with few remaining teeth or completely edentulous maxilla and only two remaining canines in the mandible were selected for this study. The two canines were endodontically treated before being prepared into dome shaped design to receive cantilevered clip bar attachment.Lower complete overdenture was constructed for each patient opposed by conventional maxillary denture. The lower overdenturewas fitted to the cantilevered bar by four clips. Two clips between the two canines and one clip distal to each canine on the cantilever extension. EMG activity of masseter and temporalis muscles was recorded for each patient during eating soft and hard food respectively after doing the needed occlusal adjustments.The location of the surface electrodes were marked on a face transparent template which was made for each patient to be used as a guide for accurate repositioning of these electrodes at the same site during the second and third EMG records. The two clips posterior to the two canines were removed from the fitting surface of the lower denture and the second EMG record was carried out. A third EMG record was done after resection of the cantilevered bar segments beyond the two canines and refitting of the denture in these areas to the ridge using self- cured acrylic resin. All the data was collected, tabulated and statistically analyzed. The results of this study revealed statistically significant decrease in recorded muscle activity of the two muscles on eating hard and soft food for the clip bar without cantilever in comparison to the cantilevered bar. Further decrease in the recorded muscle activity of the two muscles on eating hard and soft food was seen for the clip bar cantilever in comparison to the clip bar without cantilever.