Effective rehabilitation of patients with volumetric jaw defects at the present stage of development of science and technology is impossible without a comprehensive analysis of biomechanical disorders and improvement of technical aspects of operational ways to eliminate them. The aim of the study was to analyze the biomechanical activity of the chewing muscles in patients with bisphosphonate osteonecrosis based on the results of neurophysiological monitoring. 184 patients with bisphosphonate osteonecrosis of the mandibular bone were monitored, 112 of whom were men and 72 women, group 1 included 60 % of patients who had an apparatus for extracellular osteosynthesis of jaw bones fixed, and group 2 – 40 % of patients whose jaw fragments were fixed with bone mini-plates of various profiles and cross-sections.  In the preoperative period, all patients underwent general clinical studies, multispiral computed tomography, and monitoring of quality of life criteria using a modified questionnaire "The MOS 36-item Short-From Hervey". Results and discussion. Indicators in the long-term postoperative period in patients of group 1 approached the physiological norm on the healthy side and significantly improved on the affected side, compared with patients from group 2 who did not receive devices for extracellular osteosynthesis in the postoperative period. Conclusions. Ensuring the positioning of jaw bone fragments in three mutually perpendicular planes restores biomechanical balance in the dental and maxillary apparatus, which accelerates the rehabilitation of patients and predicts a favorable outcome of surgery.