Purpose - to study the etiology, prevalence, clinical course, functional examination and treatment of non-carious lesions located in the cervical area of patients with bruxism. Materials and methods. A prospective study of 200 outpatient cards of dental patients at the dental clinic of the Federal State Budgetary Educational Institution of Higher Medical Education of the KMGU of the Ministry of Health of Russia (Kursk) and Federal State Budgetary Educational Institution of Higher Medical Care of the Kuban State Medical University of the Ministry of Health of Russia (Krasnodar) in the age range from 18 to 55 years, whose average age was 38 ± 6.7 years. We studied the localization of cervical defects, etiological factors of occurrence, and also conducted an electromyographic study of the chewing muscles at rest, when the jaws were compressed and when chewing. Results. When studying the localization of cervical defects in different functional groups of teeth, defects in the cervical area of premolars were noted in 41 patients - 57%, in 18 - on canines (25%), in 10 - on incisors (13.8%), in 3 - on molars (4.2%). It was revealed that the trigger mechanism was a number of factors: partial loss of teeth (20 patients were diagnosed with partial absence of teeth of both jaws - Kennedy class III-IV without correct orthopedic treatment), 17 respondents had flattened occlusal surfaces of teeth after therapeutic treatment, 31 were diagnosed abrasion of varying severity and localization, in all patients - a violation of occlusal relationships. In 56 patients (77.77 %) a combination of several etiological factors was noted. A comparative analysis of EMG indices of paired masticatory muscles in the studied group showed that before the start of dental treatment, patients had uncontrolled bursts of bioelectric activity (BEA) in opposite muscles from opposite sides, an increase in the amplitude of muscle contractions during compression in both muscles (mostly in actually chewing ), decrease in the amplitude of muscle contractions during compression due to the rapid fatigability of muscles at rest. Conclusion. Thus, questions of etiology are still open and subject to further study. Of the many known causes, the most common are violation of occlusal relationships, muscular parafunctions, external traumatic factors, etc. The appearance of bruxism is associated with a significant risk of disturbing the occlusal relationship with a subsequent increase in the load on the tooth enamel. In this regard, a rational comprehensive dental treatment of patients with the studied combined pathology should be carried out after conducting electromyographic studies with samples of “rest”, “compression” and “chewing” strictly in accordance with the indications and timing of dynamic observation at least 1 time in 3 months.

cervical defects, wedge-shaped defect, abfraction, abrasion, bruxism, electromyographic study .