CHANGES IN HEAD AND CERVICAL-SPINE POSTURES AND EMG ACTIVITIES OF MASTICATORY MUSCLES FOLLOWING TREATMENT WITH COMPLETE UPPER AND PARTIAL LOWER DENTURE

A clinical stomatognathic, cephalometric and electromyographic (EMG) s tudy was performed in relation to 14 subjects (10 women, 4 men), each with an edentulous maxilla and residual mandibular dentition before an d six months after treatment with complete upper and partial lower den tures. The mean age of the subjects was 54.4 years (range 43-64 years) . The mean period of endentulousness and age of dentures were 22.5 yea rs (range 15-33 years) and 14.1 (range 1.5-30 years), respectively. Na tural head position was recorded (using a fluid-level method) and meas ured from cephalograms. EMG activity was measured in relation to masse ter and temporal muscles. A decrease in clinical dysfunction index was noted in 12 of 14 subjects (86%). There was no change in cervical inc lination, but a slight extension of the head was noted after treatment . Rapid recovery of the masticatory muscles was reflected in increased EMG activity, especially when biting in the maximal intercuspal posit ion. In cases of edentulous maxilla and residual mandibular anterior d entition, treatment with a complete upper and lower partial denture ha d a favorable effect on craniomandibular disorders and masticatory-mus cle function.