Journal of Dental Research, Vol 68, 800-804, Copyright © 1989 by International & American Associations for Dental Research Online Journals
EMG power spectrum patterns of anterior temporal and masseter muscles in children and adults
S. W. Yuen, J. C. Hwang and P. W. Poon
Department of Children's Dentistry and Orthodontics, Prince Philip Dental Hospital, Hong Kong.
The power spectrum of electromyograms (EMG) has been demonstrated to vary
with muscles having different muscle fiber type compositions. This study
investigated the variations in EMG power spectrum patterns of the
masticatory muscles with age and gender by comparison of the mean power
frequency (MPF) of the anterior temporal and masseter muscles in children
and adults. Surface EMG signals were sampled bilaterally from the muscles
when the subjects were performing maximum voluntary isometric clenches at
maximal intercuspal position. The results indicated that MPF values were
age-dependent (p less than 0.001), and sexual dimorphism was evident (p
less than 0.001), with lower MPF values in male and adult muscles. While
male adults had the lowest and female children had the highest MPF values,
female adults had MPF values closer to values obtained from male children.
These differences or similarities could be attributed to the degree of
differentiation of the muscles during growth and development of the
craniofacial morphology.
