The analysis of electromyographic indicators is recommended for determining the degree of functional disorders of chewing muscles. The purpose of the study was to analyze changes in adaptive processes of chewing muscles in patients with fractures of the mandible, depending on localization. Material and methods. The functional state of chewing muscles in patients with jaw fractures of different localization was determined by their bioelectric activity at the electromyographic complex "Neuro-EMG-Micro". Electromyography was performed on 24 subjects with single-function and 33 subjects with multifunctional temporomandibular disorder (major group) disorders, compared with values in 20 healthy subjects (comparative group). Index of deviation of the reduction function m. Masseter (Index of Ferrari) was determined by the formula: (MVC/RMC)×100%. The results obtained are processed statistically. Results and discussion. As a result of the conducted research it was established that in the comparative group the deviation index in the function of reduction of masticatory muscles was 90.18±6.65 % on the left and 89.20±6.94 % on the right. In patients with fractures of the mandible in the one-functional disorder of the lower jaw, the value of the analyzed parameter decreased to the left and varied from 79.42±5.35 % for median fractures to 78.87±5.41 % for fractures in the corner of mandibule, p-p2 ˂0.05. The maximum decrease in the values of the index of deviation in the function of reduction of masticatory muscles was determined at traumatic lesions of the near the cervical area and it was 72.62±5.91%, р–р3 ˂0.05. The dynamics of the values of this index for single-function disorders from the right was similar. In persons with fractures of the mandible in multifunctional temporomandibular disorder disorders with median fractures, the value of the index of deviation of the function of reducing the masticatory muscles, both right and left, was equal to those given to persons in the comparative group. At the same time, in the analysis of index markings on the left side, it was found that for lateral fractures and with a fracture of the angle of the mandible the value of this parameter was 1.4 times lower with respect to data from persons in the comparative group, p˂0.05. In the localization of fractures of the mandible in the condoyle and within the coronoid process, the index value was reduced by 1.5 and 1.6 times, before treatment by 0.01, and they differed in their statistical significance from the data of index evaluations in patients with medial fractures, p1˂0,05. A similar trend was observed in the study of index markers on the right side of this contingent of patients: with median fractures, the value of the studied parameter decreased, but did not differ statistically significant from the data of persons in the comparative group, p <0.05. Conclusions. On the basis of a multi-parameter study m. masseter with surface electromyograms, it can be concluded that the combined pathology of the maxillofacial area causes dysfunction of the masticatory muscles, especially in patients with the location of fractures in the condoyle and within the coronoid process, and causes the need for individualized therapeutic measures.

Keywords: jaw fractures, temporomandibular disorder, electromyography

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