Surface EMG of jaw-elevator muscles and chewing pattern in complete denture wearers. By Tatiana Araya

SUMMARY

The aim of this study was to investigate
the adaptation process of masticatory patterns to ahttp://www.blogger.com/img/blank.gif
new complete denture in edentulous subjects. For
this purpose, muscle activity and kinematic parameters
of the chewing pattern were simultaneously
assessed in seven patients with complete maxillary
and mandibular denture. The patients were analysed
(i) with the old denture, (ii) with the new
denture at the delivery, (iii) after 1 month and
(iv) after 3 months from the delivery of the new
denture. Surface electromyographic (EMG) signals
were recorded from the masseter and temporalis
anterior muscles of both sides and jaw movements
were tracked measuring the motion of a tiny magnet
attached at the lower inter-incisor point. The subjects
were asked to chew a bolus on the right and
left side. At the delivery of the new denture, peak
EMG amplitude of the masseter of the side of the
bolus was lower than with the old denture and the
masseters of the two sides showed the same intensity
of EMG activity, contrary to the case with the
old denture. EMG amplitude and asymmetry of the
two masseter activities returned as with the old
denture in 3 months. The EMG activity in the
temporalis anterior was larger with the old denture
than in the other conditions. The chewing cycle
width and lateral excursion decreased at the delivery
of the new denture and recovered after
3 months.
KEYWORDS: surface electromyography, chewing, jaw
muscles
Accepted for publication 20 March 2005