Masticatory Muscles In Patients Research Articles

Diagnosis of hypertonicity of the masticatory muscles at a dental appointment

Summary. The purpose of the study. Hypertonus of the masticatory muscles is a fairly common pathology that leads to the development of parafunctional masticatory activity. At the same time, the nature of the course of the pathology becomes long-lasting, leading to irreversible consequences. Patients often do not pay attention to minor pain in the area of the masticatory muscles, so hypertonus of the masticatory muscles is diagnosed randomly. In view of the variety of clinical symptoms from headaches to the phenomena of oral stomalgia, the diagnosis of hypertension is extremely difficult. Also, there is currently no single algorithm for the management of such patients.Materials and methods. In the presented scientific study, a survey of 189 patients who applied to a dental clinic for the treatment of dental caries and its complications, a professional examination was conducted. All patients were examined according to the method of diagnosis of muscle hypertonus developed by us. The methodology includes a thorough collection of anamnesis, questionnaires (PSM-25, VAS, MAS, author's methods), the use of objective research methods, including: OPTG, CT, ultrasound, the author's method of determining the degree of mouth opening.Results. Muscle hypertonus of varying severity was diagnosed in 80% of cases, high stress level on the PSM-25 scale in 71% (135), the presence of morning pain in the area of the masticatory muscles in 55%(104). An assessment of muscle tone on the MAS scale confirmed a significant increase in masticatory muscle hypertonicity in 34% of cases. These additional methods of investigation confirmed the presence of hypertonicity of the masticatory muscles in patients with an objective clinical picture. In the study of this area, the main role is played by the clinician, only if all the diagnostically valuable information is available, it is possible to formulate an optimal treatment plan and avoid aggravation of the patient's condition due to incorrect diagnosis and treatment.Conclusions. The application of the developed diagnostic method contributes to the random detection of parafunctional activity of the masticatory muscles at a dental appointment, as well as to the final diagnosis of masticatory muscle hypertonus.

Myofunctional parameters in patients using full removable dentures with progenic and prognathic ratio of the anterior segments of the edentulous jaws

The aim study was to construct artificial dentitions based on the method of mathematical modeling with the progenic and prognatic ratios of toothless frontal segments and to analyze the functional activity of the masticatory muscles in patients using dentures made in this way, compared with standard prosthetic structures. To compare and interpret the data obtained, electromyographic studies were performed in the control group (16 people), whose teeth were made using the traditional method, and the main group (22 people), whose artificial teeth were formed according to individual mathematical calculations, taking into account the size of the sagittal gap of the frontal segments of the progenic and prognatic ratio of toothless jaws. Statistical processing of the results of the electro-myographic study was carried out using the Statistica application software package. The digital data were processed by the method of variational statistics using the Student's t-test. The analysis of the obtained data showed the advantages of using individual mathematical calculations when solving the issue of tactics for constructing dentitions in the frontal segment of toothless jaws, taking into account the degree of the sagittal gap in the progenic and prognatic correlation of the jaws and their possible combinations.

СРАВНИТЕЛЬНАЯ ОЦЕНКА ПОКАЗАТЕЛЕЙ БИОЭЛЕКТРИЧЕСКОЙ АКТИВНОСТИ МЫШЦ У ПАЦИЕНТОВ СО СЪЕМНЫМИ ПОКРЫВНЫМИ ПРОТЕЗАМИ С ОПОРОЙ НА ИМПЛАНТАТЫ ПРИ ПОЛЬЗОВАНИИ В ТЕЧЕНИЕ 12 МЕСЯЦЕВ

Subject. A comparative assessment of the state of the stomatognathic system on the example of the bioelectrical activity of temporal and masticatory muscles in patients who used removable implant-supported overdentures with bar fixation system, made by two different methods: traditional and using digital methods of treatment planning and manufacturing was carried out.
 Objectives. To compare the changes of bioelectrical activity of temporal and masticatory muscles in patients with removable implant-supported overdentures made by two different methods: traditional and digital, who used dentures for a long time (12 months).
 Methods. Bioelectrical activity and symmetry of temporal and masseter muscles were investigated clinically by surface electromyography. Electromyography was performed in five probes: Rest, Light CO, Natural Swallowing, Maximal Volitional Clench (MVC) and Clench on Cotton Rolls (MVCCR).
 Results. In patients using overdentures produced in traditional way, no normal values of muscle activity were observed in any of the probes at the end of the study. In patients who used overdentures, made with the use of digital technologies, we noted a decrease of bioactivity of the muscles in the probes of Rest and Light CO, and an increase of biopotentials in the probes of MVC and MVCCR. The values obtained at the end of the study were characterized as normal or acceptable.
 Conclusions. The application of a digital method of treatment planning and fabrication of removable implant-supported overdentures with a bar fixation system allows to achieve more physiological values of temporal and masticatory muscles biopotentials, which can be interpreted as recovery of the functional integrity of the stomatognathic system.

A CLINICAL CASE OF A SUCCESSFUL COMBINED EFFECT ON THE SPASTICITY OF THE MASTICATORY MUSCLES IN A PATIENT WITH CEREBRAL PALSY

Spasticity of the masticatory muscles in patients with cerebral palsy (cerebral palsy) is noted in 60 % of cases. Due to the limited opening of the mouth, it is often very difficult for a dentist to perform manipulations in the oral cavity. First of all, it is necessary to correct the muscle tone of the chewing muscles, which is the key to the success of a full-fledged dental treatment. This article proves the effectiveness of the combined effect on the spasticity of the masticatory muscles in a patient with cerebral palsy on the example of a clinical case. The dental status, the state of the chewing muscles before the treatment and after 3 months are described. Correction of muscle hypertonicity was carried out by performing a complex of adaptive myohymnastics in combination with a pneumatic trainer after injections of abobotulotoxin type A. The first experience of combined effects on the spasticity of the masticatory muscles in a patient with cerebral palsy indicates the prospects for further development and implementation of this technique.

Evaluation of Soft Tissue Mobilization in Patients with Temporomandibular Disorder-Myofascial Pain with Referral.

The aim of the study was functional evaluation of soft tissue mobilization in patients with temporomandibular disorder-myofascial pain with referral. The study group consisted of 50 individuals—37 females and 13 males. The average age was 23.36 ± 2.14 years. All subjects were diagnosed with myofascial pain with referral (diagnostic criteria for temporomandibular disorders). Soft tissue mobilization was applied three times. Electromyography of selected masticatory muscles was performed six times—before and after the treatment. After each mobilization, a decreasing tendency of muscular activity was observed in the entire study group. The Friedman test indicated that mobilization altered the activity of the right temporal muscle (p = 0.00010), both masseters (p = 0.0000), right sternocleidomastoid (p = 0.00251), left sternocleidomastoid (p = 0.00033), and right and left digastric muscles (p = 0.00045 and p = 0.00000, respectively). With respect to symmetry a statistically significant difference was noted in the case of the sternocleidomastoid muscles (p = 0.00729). In conclusion, soft tissue mobilization seems to be effective in the relaxation of masticatory muscles in patients with temporomandibular disorders. Our findings proved that soft tissue mobilization does not improve the symmetry and synergy of the masticatory muscles limited by dental occlusion.

Effectiveness of manual therapy in masticatory muscles for tmd patients - a review of the literature

Objective: Evaluate, through a systematic literature review, the efficacy of manual therapy (MT) in the release of masticatory muscles in patients with temporomandibular disorders (TMD) compared to other forms of treatment. Methods: Electronic databases as SCOPUS, PUBMED and Web of Science were used to search for randomized controlled clinical trials. The selected trials were classified according to the Jadad scale. Results: The combined use of MT with education and self-care may be safer than performing as an isolated technique when considering a period longer than 1 year due to the maintenance of the effect. Conclusions: The included studies concluded that MT alone has significant effects on pain reduction at different follow-up periods. However, due to the diversity in number of sessions, duration of sessions and follow-up times, it becomes necessary to use standardized protocols.

Electromyographic study of neuromuscular coordination of chewing muscular at the stages of protetic treatment

The study of masticatory muscles allows timely detection of changes in their functional state, as well as to identify borderline pathological processes that can lead to the development of morphological and functional disorders in the maxillofacial region. This work was carried out in order to determine changes in the functional state of the masticatory muscles in patients with de-fects in the dentition in the lateral region before and after the orthopedic treatment. To achieve this goal, an electromyographic study of the masticatory muscles was performed in 95 patients with uni-lateral and bilateral defects of the dentition in the lateral region before and after restoration of the occlusal relationship of the dentition. As a result of the examination, pronounced malfunctions of the masticatory muscles were revealed in patients with defects in the dentition. After orthopedic treatment, a restoration of the balanced functioning of the muscular system of the maxillofacial re-gion was noted.

Effect of manual therapy on pain and electromyographic activity of masticatory muscles in patients with temporomandibular disorders

Background: Temporomandibular disorders (TMD) are disorders of multifactorial origin that affect the temporomandibular joint and/or masticatory muscles. The TMD can generate compensations where physical therapy acts through myofascial releases and joint mobilizations to restore functionality. Objective: To verify the effects of manual therapy techniques on pain and electromyographic activity (EMG) of masticatory muscles in TMD patients. Methods: This is a quasi-experimental study composed of 10 subjects with TMD and 10 healthy subjects who underwent a session of myofascial release, joint mobilization and digit-pressure on the masticatory and cervical muscles. Pain levels and electromyographic activities of the temporal and masseter muscles were bilaterally assessed during the following situations: (1) Maximum Occlusion and (2) Chewing in the right and the left side with chewing gum. Data analysis was performed using BIOMEC-SAS software, in which the data were filtered with a 4th order Butterworth bandpass filter with 20-400hz and normalized as a percentage of maximum occlusion. Data were divided into homolateral and contralateral muscles alongside chewing. EMG variables were compared by factorial ANOVA, and pain by dependent t-test. Results: TMD patients had pain level reduction during maximum occlusion (Pre:4.55±2.2; Post:2.55±1.6; p=<0.001), right chewing (Pre:2.3±2.16; Post:0.4±0.69; p = 0.02) and left chewing (Pre: 1.0±1.15; Post:0.10±0.31; p = 0.05). There was no effect of manual therapy techniques on the EMG activity bilaterally of the temporal (p = 0.617) and masseter (p = 0.926) muscles during chewing. Patients with TMD had higher EMG activities during chewing on the homolateral temporal (p = 0.001) and masseter (0.004) muscles compared to subjects without injury. Conclusion: Manual therapy techniques reduced pain level in TMD patients. No changes in EMG activity were observed after manual therapy techniques. Finally, the study provides evidence of the influence of manual therapy techniques on short-term pain.

Dynamics of changes in the level of pain in the masticatory muscles in patients with reduced interalveolar height

Цель исследования — изучить динамику изменения интенсивности боли в жевательных мышцах по Визуально-аналоговой шкале (ВАШ) при лечении пациентов со сниженной межальвеолярной высотой с помощью эластичных лент и капп. Материалы и методы. Было обследовано 52 человека (15 мужчин и 37 женщин) со сниженной межальвеолярной высотой, страдающих гипертонией жевательной мускулатуры. Диагноз выставляли по результатам клинических и параклинических (электромиография) методов исследования. Интенсивность боли оценивали с помощью ВАШ. Контрольную группу составил 31 практически здоровый человек в возрасте от 16 лет до 31 года. Лечение пациентов основной группы на подготовительном этапе проводилось с помощью разработанного нами метода сочетанного использования эластичных лент и капп. Результаты. Установлено, что предложенный метод лечения гипертонии жевательных мышц у пациентов со сниженной межальвеолярной высотой способствует значительному (Z1—3= –6,40; p1—3=0,01) снижению интенсивности боли, напряженности, усталости в жевательных мышцах уже к концу 2-й недели терапии (с 8,17±0,6 до 4,54±0,5 баллов по шкале ВАШ), что подтверждается в том числе снижением биоэлектрической активности жевательных мышц. Заключение. Таким образом, предложенная методика лечения гипертонии жевательных мышц у пациентов со сниженной межальвеолярной высотой обладает качествами, выгодно отличающими ее от других известных способов, благодаря их функционированию в щадящем режиме.

Chewing muscles functional status assessment in patients with TMJ muscular-articular dysfunction while using of soft occlusal splint

Currently, the functional diagnosis of the entire dentition state is becoming an integral part of orthodontic and temporomandibular joint (TMJ) disorders correction. Aim — to study the functional state of the masticatory muscles in patients with muscular-articular dysfunction before and after using an soft occlusal splint. Materials and methods. A comprehensive examination of 478 patients (63% women, 37% men), aged 18 to 50 years, with various types of the dentition occlusion and muscular-articular TMJ dysfunction was performed. The main methods of functional diagnostics included: 1) masticatory muscle electromyography on Synapsis electromyograph (NeuroTech, Russia); 2) occlusion computer analysis with T-Scan III (Teksan, USA). Results. This work has established, based on the masticatory muscles functional state study, that bioelectrical activity was higher in the temporal muscles than in the masticatory muscles with the coefficient of symmetry from 2 to 4.5 in 65% of patients. After using an soft occlusal splintfor 6—12 months, the data of functional research methods confirm an improvement in the state of masticatory muscles in 84% of patients with TMJ. Conclusions. The obtained results have confirmed the fact of the masticatory muscles functional state improving with effectiveness of an soft occlusal splint use in patients with muscular articular TMJ dysfunction.

Myorelaxant Effect of Transdermal Cannabidiol Application in Patients with TMD: A Randomized, Double-Blind Trial.

(1) Background: The healing properties of cannabidiol (CBD) have been known for centuries. In this study, we aimed to evaluate the efficiency of the myorelaxant effect of CBD after the transdermal application in patients with myofascial pain. (2) Methods: The Polish version of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD Ia and Ib) was used. A total of 60 patients were enrolled in the study and were randomly divided into two groups: Group1 and Group2. The average age in Group1 was 23.2 years (SD) = 1.6 years) and in Group2, it was 22.6 years (SD = 1.86). This was a parallel and double-blind trial. Group1 received CBD formulation, whereas Group2 received placebo formulation for topical use. The masseter muscle activity was measured on days 0 and 14, with surface electromyography (sEMG) (Neurobit Optima 4, Neurobit System, Gdynia, Poland). Pain intensity in VAS (Visual Analogue Scale) was measured on days 0 and 14. (3) Results: in Group1, the sEMG masseter activity significantly decreased (11% in the right and 12.6% in the left masseter muscles). In Group2, the sEMG masseter activity was recorded as 0.23% in the right and 3.3% in the left masseter muscles. Pain intensity in VAS scale was significantly decreased in Group1: 70.2% compared to Group2: 9.81% reduction. Patients were asked to apply formulation twice a day for a period of 14 days. (4) Conclusion: The application of CBD formulation over masseter muscle reduced the activity of masseter muscles and improved the condition of masticatory muscles in patients with myofascial pain.

Bruxism: methods of application and results of treatment with botulinum neuroprotein (Relatox)

The article substantiates the need for the use of botulinum therapy in the management of bruxism as a movement disorder. We present the technique of injecting a new Russian botulinum neuroprotein Relatox into the masticatory muscles of patients with bruxism. We have the positive clinical effects of botulinum therapy, a decrease in the level of pain on the visual analogue scale, normalization of muscle activity according to the surface electromyography of masticatory muscles, a decrease in number of nocturnal bruxism according to abrasion on the foil surface on Brux Checker are shown.

Evaluation of the impact of preoperative use of dexamethasone and cyclobenzaprine in surgical extraction of lower third molars on trismus by electromyographic analysis.

The aim of this study was to evaluate the influence of cyclobenzaprine and dexamethasone on ​the electrical activity of the masticatory muscles in patients who had undergone lower third molar surgery. Thirty bilateral impacted lower third molars with indication of extraction were randomised into three groups: the control group, the dexamethasone, and the cyclobenzaprine group. To obtain muscular electrical activity and mouth opening, an electromyographic device was used at mandibular rest and maximum voluntary contraction and compared pre- and post-operatively. During muscle contraction, no significant difference was observed in the electromyographic records on the non-operated side. On the operated side, there was a reduction in electrical activity for both drugs pre-operatively and immediately post-operatively compared to the control group. All pharmacological agents promoted a higher mouth opening compared to control group. The results suggest that dexamethasone and cyclobenzaprine may be useful as an adjuvant in the prevention of motor dysfunctions in third molar surgery.

Increased Apparent Diffusion Coefficient Values of Masticatory Muscles on Diffusion-Weighted Magnetic Resonance Imaging in Patients With Temporomandibular Joint Disorder and Unilateral Pain

Myalgia of the masticatory muscles is difficult to evaluate quantitatively. The purpose of the present study was to quantitatively assess myalgia of the masticatory muscles in patients with temporomandibular disorders (TMDs) using the apparent diffusion coefficient (ADC) on diffusion-weighted magnetic resonance imaging (MRI). Patients who had undergone MRI with clinically diagnosed TMDs according to the criteria of the American Academy of Orofacial Pain and unilateral temporomandibular joint pain from March 2015 to January 2017 were prospectively enrolled. The MRI techniques used included axial diffusion-weighted imaging (DWI) and short T1 inversion recovery imaging through the neck to the skull base. The regions of interest were drawn to completely include the right and left lateral pterygoid muscles, medial pterygoid muscles, and masseter muscles on a slice demonstrating the largest area of each muscle on the ADC map. We compared each masticatory muscle of the pain side with those of the contralateral side without pain. A total of 106 patients with TMD had met the inclusion criteria (18 males, 88 females; mean age, 48.7years; range, 16 to 80). The mean ADC values of the masticatory muscles of the pain side were significantly greater than those of the no-pain sides (P<.01), as were those for the lateral pterygoid muscles (1.35±0.79×10-3mm2/second vs 1.13±0.77×10-3mm2/second), medial pterygoid muscles (1.28±0.46×10-3mm2/second vs 1.05±0.69×10-3mm2/second), masseter muscles (1.33±0.78×10-3mm2/second vs 1.09±0.64×10-3mm2/second). The ADC values of the masticatory muscles on the pain side were significantly greater than those of the contralateral side without pain. Our results suggest that DWI could be used to assess myalgia of the masticatory muscles quantitatively.

Comparative characteristics of masticatory muscle tone in patients with compensated and decompensated increased teeth abrasion

Relevance. Increased dental abrasion frequent nosological form of dentistry. In young people, PSZ is less common (6.3%) than in middle-aged people (32.7%), as well as people of older age groups (11.8-20.6%). Among foreign researchers, "rejuvenation" of increased teeth abrasion is noted in many countries, including developed ones. In the UK, in dental clinics, this pathology is 30% among people under 30 years and 42.6% among people 30-50 years, in Sweden – 29.9%, in the United States of America – 25%. To study the tone of the masticatory muscles in patients with various forms of increased teeth abrasion.Material and methods. A myotonometric examination and orthopedic treatment of 185 patients of the second period of adulthood (35-60 years) with increased abrasion of teeth in the clinic of dentistry of St. Petersburg state pediatric medical University.Results. The paper presents qualitative indicators of myotonometry of masticatory muscles in patients with compensated and decompensated increased abrasion of teeth, which are compared with the norm.Conclusion. A characteristic feature of patients with a compensated form of increased teeth abrasion is the absence or slight decrease in the height of the gnatic part of the face and increased functional tone of the masticatory muscles. For decompensated increased teeth abrasion is characterized by a combination of abrasion with a decrease in the height of the lower face and reduced functional tone of the masticatory muscles.

The role of electrophysiological investigations of masticatory muscles in patients with persistent idiopathic facial pain.

The authors tried to establish whether there is any electrophysiological difference of masticatory muscle activity between patients with persistent idiopathic facial pain (PIFP) and healthy subjects. Twenty-eight PIFP patients (6 men and 22 women, mean age 40years) and 28 normal subjects (12 men and 16 women, mean age 40years) underwent EMG of temporal and masseter muscles before and after transcutaneous electric nerve stimulation (TENS). After TENS stimulation, the mean amplitude difference was found to be smaller than the baseline before TENS in the PIFP patients compared with healthy subjects. The peculiar behavior of masticatory muscles after TENS could be relevant in order to explain the well-known improvement of pain reported by some PIFP patients after orthosis positioning.

Effect of injection of botulinum toxin on decreasing the symptoms and signs of masticatory muscles in patients with temporomandibular dysfunction.

Background. Temporomandibular joint dysfunction (TMD) is a term that describes problems in the masticatory system, including the temporomandibular joint, the dento-muscular system and the supporting bones. Injection of botulinum toxin, as a noninvasive technique, might be useful in decreasing symptoms such as muscular spasm, dystonia, migraine headaches and TMD. Therefore, the aim of the present study was to evaluate the effect of injection of botulinum toxin on decreasing the symptoms and signs of masticatory muscles in patients with TMD. Methods. A total of 61 patients were consecutively included in the present study in 2016‒2017. All the subjects received a 50-unit injection of Dysport botulinum toxin in the masseter muscles using an extraoral injection technique. The results of the injection were evaluated in terms of pain severity using VAS, clinical evaluations of the joint click through palpation and by determining the inter-incisal distance. The patients underwent follow-up examinations at 1-week, 3-month and 6-month intervals after injection. Data were analyzed with appropriate statistical tests. Results. Comparison of pain severity and articular clicks at different intervals showed decreases in these parameters over time, with significant differences between the time intervals (P<0.05). Comparison of mouth opening at different intervals showed increases in mouth opening over time. Conclusion. The results of the present study showed that injection of botulinum toxin can be used in patients with TMD as a non-invasive treatment modality

EMG-CHARACTERISTIC OF MASTICATORY MUSCLES IN PATIENTS WITH CLASS II MALOCCLUSION AND TEMPOROMANDIBULAR DISORDERS

Introduction: A stable state of musculoskeletal system is provided by harmony of occlusion, the anatomy of temporomandibular joints, and the activity of the masticatory muscles under the control of peripheral and central nervous system. Surface electromyography (EMG) is a well-used modality and is used in dentistry to access the status of the muscles of mastication. The aim of the research was to evaluate the EMG-characteristic of masticatory muscles in patients with TMD and Angle Class II malocclusion. Materials and methods: The study comprised 23 patients with Angle Class II malocclusion and TMD. The average age of the subjects was 26,5 ± 2,3 years. Malocclusion was evaluated according to Angle classification, TMD - according to the Research Diagnostic Criteria (RDC/TMD). Registration of EMG-activity of masseter and anterior temporalis muscles was performed during maximum voluntary clenching, clenching on the right and left sides. Results: EMG-activity of masticatory muscles are characterized by: 1) increased values of EMG-activity of temporal and masseter muscles - peak and average amplitude in tests of unilateral clenching and maximum clenching (values are greater than 2000 μV); 2) in unilateral clenching of jaws (on the left or right) the increased EMG-activity was detected on the balancing side; 3) in unilateral clenching of jaws (on the left or right) the increased muscle activity on the working side with disproportional (asymmetric) load distribution between masseter and temporal muscles has been found. Conclusions: Patients with Angle Class II malocclusion and TMD were found features of EMG-activity of masticatory muscles.

Morphometric and morphological changes of the masticatory muscles in patients with temporomandibular joint dysfunction and masticatory muscles according to MR data

Представлены результаты измерения жевательных мышц, собственно жевательных, медиальных и латеральных крыловидных, и изучения их морфологических изменений у 51 пациента с дисфункцией ВНЧС и жевательных мышц. Данные получены анализом МР-изображений ВНЧС. Результаты исследования указывают на увеличение толщины и дегенеративные изменения латеральных крыловидных мышц у пациентов с внутрисуставными нарушениями ВНЧС и на увеличение толщины и дегенеративные изменения собственно жевательных мышц у пациентов с преимущественно внесуставными проявлениями дисфункции.

ELECTROMYOGRAPHIC CHARACTERISTICS OF CHEWING MUSCLES OF INDIVIDUALS WITH PATHOLOGICAL ABRASION OF HARD DENTAL TISSUES

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.