Masticatory Muscle Activity In Patients Research Articles

Use of Surface Electromyography to Evaluate Effects of Therapeutic Methods on Masticatory Muscle Activity in Patients with Temporomandibular Disorders: A Narrative Review

The presented narrative review aims to present the impact of therapeutic methods on the masticatory muscle activity measured using surface electromyography (sEMG) in patients with temporomandibular disorders (TMDs). Original interventional studies with baseline data for diagnosed TMD groups with full-text articles in English published in scientific journals in the last ten years were included in the evaluation process. The following narrative review considered only clinical, controlled, and randomized studies. Articles that included the following parameters were qualified for this review: adult participants, diagnosis of temporomandibular disorder, the presence of a musculoskeletal dysfunction, no other severe comorbidities, use of therapeutic interventions, and sEMG measurement before and after the intervention. Ten papers were accepted and analyzed for the final evaluation in the presented review. Several studies using surface electromyographic examination prove the effectiveness of various therapies to normalize the bioelectrical activity of the masticatory muscles, either reduction during rest or increase during a functional task in patients diagnosed with temporomandibular disorders. This narrative review shows the influence of manual and physical treatments on electromyographic masticatory muscle activity, including soft tissue mobilization, transcutaneous electrical nerve stimulation, low-level laser therapy, and moist heat therapy. Changes in masticatory muscle activity coincided with changes in TMD-associated pain and range of mandibular mobility.

Surface electromyography in the assessment of masticatory muscle activity in patients with pain-related temporomandibular disorders: a systematic review.

Temporomandibular disorders (TMD) are a set of painful conditions affecting the orofacial region that are prevalent and constitute the most frequent type of non-dental pain complaint in the maxillofacial area. Pain-related TMD (TMD-P) is characterized by ongoing pain in the masticatory muscles, the temporomandibular joint, or surrounding structures. Due to the multiple factors that contribute to the development of this condition, it can be challenging to accurately diagnose. One of the useful method for assessing patients with TMD-P is surface electromyography (sEMG). The aim of this systematic review was to provide a comprehensive overview of the current scientific literature on the evaluation of masticatory muscle activity (MMA) in individuals diagnosed with TMD-P, through the utilization of sEMG. To gather relevant information, electronic databases such as PubMed, Web of Science, Scopus, and Embase were searched using specific keywords including: "pain" AND ("temporomandibular disorder*" OR "temporomandibular dysfunction*") AND "surface electromyography" AND "masticatory muscle activity." The inclusion criteria were studies assessing MMA in patients with TMD-P using sEMG. The Effective Public Health Practice Project (EPHPP) Quality Assessment Tool for Quantitative Studies was utilized to evaluate the quality of the studies that were included in the review. The search strategy identified 450 potential articles. Fourteen papers met the inclusion criteria. Global quality rating for significant part of the articles was weak. Most studies showed greater sEMG activity of the masseter (MM) and temporal anterior (TA) muscles at rest in TMD-P subjects than in the asymptomatic controls, while the MM and TA muscles were less active in the pain-related TMD group compared to the non-TMD group during maximal voluntary clenching (MVC). There were differences in MMA in the TMD-pain population compared to a healthy control group during various tasks. The diagnostic efficacy of surface electromyography in assessing individuals with TMD-P remains unclear.

The Difference in Electromyographic Activity While Wearing a Medical Mask in Women with and without Temporomandibular Disorders

Wearing a medical mask influences resting activity of the temporalis anterior and masseter muscles in healthy young women. However, no studies link medical mask-wearing with masticatory muscle activity in patients with temporomandibular disorders (TMDs). Therefore, this study aims to compare electromyographic patterns while wearing a medical mask between women with and without temporomandibular disorders. Based on the Research Diagnostic Criteria for Temporomandibular Disorders, 115 adult women qualified for the study. Participants were divided into the following two groups: diagnosed TMDs (n = 55; mean age: 23.5 ± 2.3 years) and healthy women (n = 60; mean age: 23.7 ± 2.6 years). Examinations of the resting and functional electromyographic activity of the temporalis anterior (TA), superficial masseter (MM), anterior bellies of the digastric muscle (DA), and the middle part of the sternocleidomastoid muscle (SCM) were carried out using the BioEMG III™. Both groups showed statistically significant decreases in resting masticatory muscle activity during medical mask examination compared to no mask measurement. The significant differences in no mask measurement between both groups were noted regarding resting masticatory activity, clenching in the intercuspal position, and clenching on dental cotton rollers. During medical mask examination, women with TMDs showed differences in resting masticatory activity and clenching on dental cotton rollers compared to the healthy group. In all analyzed variables, both groups showed similar electromyographic patterns in the maximum mouth opening measurement during medical mask and no mask examination. A medical mask influences the resting bioelectric activity of the masticatory muscles in women with temporomandibular disorders and healthy women. We observed differences and some similarities in resting and functional electromyographic patterns within masticatory and neck muscles in both groups during medical mask and no mask examination.

Comparative study of surface electromyography of masticatory muscles in patients with different types of bruxism.

BACKGROUNDBruxism is a rhythmic masticatory muscle activity that occurs involuntarily in a non-physiologically functional state. There is a lack of research classifying the functional status of masticatory muscles in patients with different mandibular movement types (centric clenching or eccentric grinding) of bruxism.AIMTo assess the differences of the masticatory muscle activity in patients with different types of bruxism.METHODSA total of 21 subjects with centric bruxism (CB) and 21 subjects with eccentric bruxism (ECB) were screened from college students according to a questionnaire and their tooth wear features. Sixteen subjects with no bruxism were also recruited. The surface electromyography (EMG) signals of the temporalis anterior (TA) and superficial masseter muscle (MM) were measured in different mandibular positions and during the chewing task. The EMG amplitude and chewing cycle duration parameters were then analyzed.RESULTSThe CB group showed fewer muscle maximal motor units, with the MM being more pronounced, a higher proportion of muscle contractions to be recruited for the same load of chewing activity, and a longer chewing cycle. The ECB group showed more TA maximal motor units and higher MM activity on the non-working side in unilateral chewing.CONCLUSIONCB mainly affects the MM, and patients with CB show reduced masticatory muscle contraction efficiency and chewing cycle efficiency. ECB mainly affects the TA, and patients with ECB show enhanced contraction of non-functional lateral muscle bundles.

Evaluation of Masticatory Muscle Function Using Digital versus Traditional Techniques for Mockup Fabrication: A Controlled Prospective Study

Background: the aim of this longitudinal prospective study was to analyze the effect of digital and traditional mockup on masticatory muscle activity in patients with teeth wear, rehabilitated with an increase of occlusal vertical dimension. Subjects and Methods: a sample of 22 adult patients who were about to receive a prosthetic rehabilitation was divided into a study group (3M; 9F; mean age 42 ± 0.8 years), treated using the digital mockup; and a control group (2M; 8F; mean age 37 ± 0.5 years), treated using the conventional technique (traditional) mockup. Electromyographic activity of anterior temporalis and masseter muscles were evaluated before the beginning of the treatment (T0), at mockup insertion (T1), after treatment (T2) and each lapse of time lasted 2–5 months. Results: the comparison between the two groups at different time gaps revealed that at ∆1 (T1–T0) only the impact index (IMP) showed significant difference and no other significant variation was observed between the two groups at ∆2 (T2–T1) and ∆3 (T2–T0). It concludes that traditional and digital methods generally have nonsignificant differences. Conclusions: both methods seem to be effective in prosthetic rehabilitation and give comparable effects on masticatory muscles.

Electromyography as a Means of Assessing Masticatory Muscle Activity in Patients with Pain-Related Temporomandibular Disorders.

Aim The aim of this study was to evaluate masticatory muscle electrical activity in patients with pain-related and pain-free temporomandibular disorders (TMDs) as well as in subjects with no TMD. Methods Ninety children with mixed dentition were recruited to the study. Of this total, 30 subjects were diagnosed with pain-related TMD (TMD-P), 30 with pain-free TMD (TMD-PF), and 30 without TMD. We used Axis I of the Research Diagnostic Criteria for TMD (RDC/TMD) to assess the presence of TMD in the examined children. The electromyographical (EMG) potentials of the temporalis and masseter muscles were measured with a DAB-Bluetooth Instrument (Zebris Medical GmbH, Germany) at rest and during maximum voluntary clenching (MVC). Results An analysis of the EMG recordings showed statistically significant intergroup differences in masticatory muscle electrical activity at rest and during MVC. Significantly higher rest temporalis muscle activity was noted in pain-related TMD subjects compared with that children from the pain-free TMD and non-TMD groups, as well as in TMD-PF children in relation to those without TMD. The EMG potentials of the temporalis muscle during MVC were much lower in patients with TMD-P than in pain-free TMD and non-TMD subjects. Masseter muscle activity at rest in the TMD-pain group was significantly greater, and masseter muscle EMG potentials during clenching were markedly lower than in patients with no TMD diagnosis. Conclusion The use of electromyography to assess masticatory muscle function revealed alterations in the pattern of temporalis and masseter muscle activity in patients with pain-related TMD compared with the pain-free subjects.

EFFECT OF ATTACHMENT RESILEINCY ON MUSCLE ACTIVITY IN IMPLANT RETAINED MANDIBULAR OVERDENTURE

Objectives: This study aimed to investigate masticatory muscle activity in patients treated with2 modalities of implant mandibular overdenture prosthesis.Methodology: Fourteen completely edentulous male patients were selected and four implantswere inserted for each patient. After 3 months of installation, the patients were equally divided intotwo groups; group I receiving overdentures retained with ball attachments and group II receivingtelescopic retained overdentures. Muscle activity was measured at time of denture insertion, twoweeks and one month after insertion.Results: The results revealed that muscle activity was significantly lower in telescopic retainedoverdentures compared to overdentures retained with ball attachments.Conclusion: Telescopic attachments decreased the effort exerted by the muscles compared toball and socket attachments.

Erratum to: Evaluation of masticatory muscle activity in patients with unilateral posterior crossbite before and after rapid maxillary expansion.

Erratum to: Evaluation of masticatory muscle activity in patients with unilateral posterior crossbite before and after rapid maxillary expansion.

Evaluation of masticatory muscle activity in patients with unilateral posterior crossbite before and after rapid maxillary expansion.

The relationship between unilateral posterior crossbite (UPCB) and the possible asymmetric activation of the jaw muscles in children is still under debate. This study aimed at evaluating the jaw muscle activity of children with UPCB before and after rapid maxillary expansion (RME) by means of surface electromyography and a standardized sampling protocol. Twenty-nine children with UPCB (UPCB-group, mean age 9.6 ± 1.6 years) and 40 UPCB-free controls (Control-group, 10.5 ± 1.1) were recruited. The activity of the left and right anterior temporalis (AT) and superficial masseter muscles (MM) was recorded during maximum voluntary clenching and a chewing task (T0). In the UPCB-group, data were collected, also, after the correction of the UPCB with RME (T1) and 6 months later (T2), without any further treatment. Electromyographic indices comparing the activity of paired muscle were computed via software to estimate the extent of asymmetric AT and MM activity. Paired and unpaired t-test or Wilcoxon-signed rank and Mann-Whitney U test, ANOVA or Friedman test and chi-squared test were used in the statistical analysis. Both groups presented with asymmetric activity of the muscles, which did not differ between groups (T0, all P > 0.05). The treatment determined a decrease in muscular activity (T1, P = 0.040), and a more asymmetric pattern of muscle activation during chewing (T1, P = 0.040), which returned similar to baseline values at T2 (all P > 0.05). UPCB does not contribute to an asymmetric activation of AT and MM during functional tasks. The treatment of UPCB by RME did not determine a more symmetric activity of the assessed muscles.

Biting Force and Muscle Activity in Implant-Supported Single Mandibular Overdentures Opposing Fixed Maxillary Dentition.

This study aimed to investigate the relation between biting force and masticatory muscle activity in patients treated by 3 modalities of single mandibular dentures. Forty implants were placed in 10 patients with completely edentulous mandibles. The study was divided into 3 treatment stages. Initially, each patient received a conventional mandibular complete denture. At the second stage, 4 mandibular implants were placed and the denture was refitted to their abutments. Third stage comprised connecting the denture to the implants through ball attachments. During each treatment stage, maximum biting force and muscle activity were measured during maximum clenching and chewing of soft and hard food. Biting force demonstrated a statistically significant increase by time for the 3 treatment stages. The highest muscle activity was recorded for the conventional denture followed by the implant-supported overdenture without attachment, whereas the lowest values were recorded for the implant-supported overdenture with attachment. Biting force was related mainly to the quality of denture support. Muscle activity was higher in patients with conventional denture than with implant-supported prostheses (with or without attachments).

The effect of mandibular advancement appliances on awake upper airway and masticatory muscle activity in patients with obstructive sleep apnoea

There is little understanding of how dental appliances, designed to posture the mandible forwards, act on pharyngeal airway dilatory and masticatory muscles in patients with obstructive sleep apnoea (OSA). This study evaluates, in a prospective cohort design, the effect of mandibular advancement splints (MAS) on awake genioglossus (GG), geniohyoid (GH) and masseter (M) muscle activity. Fifty OSA patients received a custom-made removable Herbst MAS appliance, adjusted for maximum therapeutic benefit, as judged by subjective improvement. Awake electromyographic (EMG) activity was recorded at baseline and with the MAS in situ, by using bipolar surface electrodes in patients seated upright and in the natural head position. The lower splint was modified to facilitate the placement of the intra-oral bipolar surface electrodes used to record GG EMG activity. Significant increases in GG (P = 0.041), GH (P<0.001) and M (P<0.001) muscle activity accompanied placement of the MAS. These findings support the contention of a physiological role, which may act to augment the anatomical action of MAS.

Electromyographic Study of Masticatory Muscle Activity in Patients with Spastic Cerebral Palsy

Electromyographic Study of Masticatory Muscle Activity in Patients with Spastic Cerebral Palsy