Evaluation of masticatory muscle activity in complete denture wearers before and after prosthetic treatment

Introduction
Muscle activity associated with mandible mobility depends on age. In the period of puberty and development of the masticatory system, a general increase in activity is observed, followed by relative stability until about 40-50 years of age. In subsequent years, the value of bioelectrical potentials decreases. The aim of the study was to evaluate activity of the chewing muscles in complete denture wearers before and after prosthetic treatment.

Material and methods
The study group consisted of 50 edentulous people including 35 women and 15 men (age 44-86 years, mean 69.18 ± 10.00). All the patients received a new set of complete dentures. The activity of the following pairs of muscles were measured: anterior part of the temporal, masseter, digastric, and sternocleidomastoid. All registrations were performed three times: with the presence of currently used old dentures, in the first day of using new dentures, and three months after adaptation. Activity of the muscles was noted in the maximum intercuspation and with opened mouth.

Results
The results of this study revealed statistically significant differences in activity of the temporal, masseter, and digastric muscles before and in the first day of using new dentures. After three months of adaptation statistical differences were observed only in the case of masseter muscles, right temporal, and left digastric. In the first day of using new complete dentures a decreasing tendency of muscular activity was noted. After three months of adaptation the muscular activity increased.

Conclusions
Fabrication of new complete dentures associated with reconstruction of vertical occlusal dimension, changes in the central position of the mandible, and modification of the occlusion of the artificial teeth leads to a temporary reduction of activity in the chewing muscles and then, after a period of adaptation and incorporation, to growth.