Novel Functional Indices of Masticatory Muscle Activity

Abstract

The aim of the present study was to analyze novel functional indices of masticatory muscle activity and compare them to existing and commonly used indices in patients with temporomandibular disorders (TMDs) and healthy adults. Based on the Research Diagnostic Criteria for Temporomandibular Disorders, 78 adult women qualified for the study. Subjects were divided into two groups: diagnosed TMDs (n = 36; mean age: 23.4 ± 2.6 years) and healthy adults (n = 42; mean age: 22.4 ± 2.3 years). Measurements of the bioelectric activity of the temporalis anterior (TA), superficial masseter (MM), and anterior bellies of the digastric muscle (DA) were carried out using the BioEMG III ™. Functional Clenching (FCI) and Functional Opening (FOI) indices were obtained as the ratio of the difference between the mean muscle root mean square (RMS) potentials during functional activity, including clenching (CL) and opening (MMO), and mean muscle resting (REST) potentials. Next, based on FCI and FOI indices, the Functional Clenching Activity Index (FCAI), Functional Clenching Symmetry Index (FCSI), and Functional Opening Symmetry Index (FOSI) were obtained. The statistical analysis showed significant differences in activity index left-sided (AcIL) and Activity index both-sided (AcItot) between TMDs and healthy women during rest measurements. The significant differences between both groups were noted in terms of all Functional Clenching Indices except Functional Clenching Index for MM right-sided (FCIMM-R). In all analyzed FCI indices, the control group showed higher values compared to the TMDs. Moreover, a significant difference between TMDs and controls was observed within Functional Clenching Activity Index left-sided (FCAIL) (14.56 vs. −0.45, p = 0.01). Both functional indices, and asymmetry (AsI) and activity (AcI) indices seem to be reliable in assessing symmetry and activity within masticatory muscles. Further studies should be performed to verify the effectiveness and suitability of the assessment of masticatory muscles using functional indices.

The Influence of Visual Input on Electromyographic Patterns of Masticatory and Cervical Spine Muscles in Subjects with Myopia

“…Functional Clenching (FCI) and Functional Opening (FOI) indices were obtained as the ratio of the difference between the mean muscle RMS potentials during activity, including clenching (CL) and opening (MMO) and the mean resting (REST) potentials, were proposed by Ginszt and Zieli ński [28] using the following formulas:…”

“…Next, based on FCI and FOI indices, the following formulas were used for the assessment Functional Clenching Activity Index (FCAI), Functional Clenching Symmetry Index (FCSI), and Functional Opening Symmetry Index (FOSI) [28]: The functional indices allow to determine the presence of asymmetry in the activity of the masticatory muscles while taking into account the functional and resting activity. The disturbance of the proportion between resting and functional activity may indicate an imbalance within the masticatory organ, which has been observed in patients with TMDs.…”

“…The disturbance of the proportion between resting and functional activity may indicate an imbalance within the masticatory organ, which has been observed in patients with TMDs. The decrease in functional indices' values may be associated with an abnormal/compensatory pattern of masticatory muscle activity [28].…”

Electromyographic Study of Masticatory Muscle Function in Children with Down Syndrome

“…As mentioned earlier, sEMG is a non-invasive technique for evaluating muscle function and efficiency by recording muscle activity from the surface over the muscle on the skin using a pair of electrodes. This method allows for objective muscle assessment and can provide some relevant qualitative and quantitative information [16]. In this way, it may be a useful diagnostic tool in children with muscle hypotonia.…”

“…The sEMG signals, conducted through tissues and recorded by surface electrodes, represent the temporal and spatial summation of the populations of nearby motor units [14]. This method is widely applied in dentistry in both clinical and research conditions [15,16]. What is important, as sEMG is simple and safe, is that it could be used in studies on children [11,17,18].…”