Electromyographic Studies of Patient Adaptation to Dentures

Abstract

Using electromyography, I evaluated the adaptation of patients to recently placed dentures. Electromyograms (EMG) of the bilateral anterior temporal and masseter muscles were recorded in 5 patients together with mandibular kinesiograph (MKG) motions during mastication and clenching at the time of insertion of new dentures and for 4 weeks thereafter. The same recordings were made for patients who had dentures that had been in use for some time.
      EMG bursts during mastication were recorded before and after tooth contact, and the duration and integrated values were measured. EMG bursts during clenching and their integrated values were also measured. EMG burst duration and the duration preceeding tooth contact (DPTC) were longer for the new denture than with the old one for the first three days of wearing the new denture. The coefficient of variance (CV) for the EMG parameters, especially that for the burst duration and DPTC, were higher for the first three days for the new denture. After three weeks of wearing the new denture, the CV for the duration and the DPTC were lower than with the old denture. The CV for the activity preceding tooth contact (APTC) was higher for the first three days of wearing the new denture than with the old denture. EMG actvities of clenching were higher for the first three days for the new denture. After three weeks of wearing the new denture, EMG actvities of clenching were lower than with the old denture.
      The results suggest that the CV of burst duration, the CV of DPTC, and burst activities during clenching, are effective factors in evaluating patient adaptation to dentures.