Masticatory Myoelectric Side Modular Ratio Asymmetry during Maximal Biting in Women with and without Temporomandibular Disorders

Abstract

There is no consensus on the role of electromyographic analysis in detecting and characterizing the asymmetries of jaw muscle excitation in patients with temporomandibular disorders (TMD). To analyze the TMD patients (n = 72) in comparison with the healthy controls (n = 30), the surface electromyography (sEMG) of the temporalis anterior muscle (TA) and masseter muscle (M) was recorded while a maximal biting task was performed. The differences in the asymmetry of the relationship between the masseter muscles were assessed in a module to determine the sensitivity (Sn) of binomial logistic models, based on the dominance of the TA or the M muscle, in accurately predicting the presence of TMD. All assumptions were met, and comparisons between the groups showed significant differences for the TA muscle ratio (p = 0.007), but not for the M muscle ratio (p = 0.13). The left side was predominant over the right side in the TMD group for both the TA (p = 0.02) and M muscles (p = 0.001), while the non-TMD group had a higher frequency of the right side. Binary logistic regression showed a significant model (χ2 = 9.53; p = 0.002) for the TA muscle with Sn = 0.843. The model for the M muscle also showed significance (χ2 = 8.03; p = 0.005) with Sn = 0.837. The TMD patients showed an increased TA muscle ratio and asymmetry of left dominance, compared to the healthy subjects. Both of the binomial logistic models, based on muscle dominance TA or M, were moderately sensitive for predicting the presence of TMD.

Unilateral temporomandibular joint disorders diagnosed as both disc displacement without reduction and osteoarthritis show vertical craniofacial asymmetry in women

“…In contrast, the control group might have had abnormal clinical symptoms despite normal MRI and CBCT ndings. Additionally, as masticatory muscle imbalances can affect asymmetry, [35] different results may have been obtained if the participants were divided according to their clinical symptoms. Therefore, there may be a certain level of natural facial asymmetry due to the aforementioned factors.…”

Multifunctional Evaluation Technology for Diagnosing Malfunctions of Regional Pelvic Floor Muscles Based on Stretchable Electrode Array Probe

“…Handheld devices are used for measuring the mechanical properties of PFM [ 14 ]. The surface electromyogram (sEMG) is the main technology for evaluating the PFM activity status in clinic [ 8 , 15 , 16 , 17 ]. However, traditional rigid dual-channel probe is used to collect the sEMG signal of PFM, which cannot characterize the complex PFM structure because it can only collect the sEMG signal of integral PFM rather than the detailed information of the muscles [ 18 , 19 ].…”