Introduction: Pathological abrasion of hard dental tissues is accompanied by both morphological and functional disorders of the dentofacial system. Among the functional changes, changes in the bioelectrical activity of the masticatory muscles are primarily considered. The aim was to study the functional state of the masticatory muscles in patients with pathological abrasion of hard dental tissues of varying degrees of severity compared with the norm.

Materials and methods: Electromyographic studies were conducted in 89 patients aged 18 to 59. 70 patients had pathological abrasion of hard dental tissues of various degrees and 17 patients had intact dentitions and physiological forms of occlusion.

Results: The results of electromyographic studies showed an extension of the chewing period, a reduced chewing rhythm, a deterioration of chewing efficacy in case of the pathological abrasion of teeth, compared with the norm, which increased in dynamics. The correlation between excitatory and inhibitory processes, however, sharply deteriorated with an increase in the duration of activity due to the reduction of the relative bioelectric rest period. The magnitude of the biopotential amplitude decreased relative to the norm with a serious violation of the coordination of masticatory muscles in general.

Conclusions: The results of electromyographic studies of the masticatory muscles make it possible to determine the degree of functional changes in the neuromuscular system of the dentofacial system of patients with pathological abrasion of hard tissues of varying severity, compared with the norm. This indicates a decrease in chewing efficacy and the progression of morphological disorders that increase in dynamics.