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Aim and objective The purpose of this work is to investigate by electromyographic (EMG) surface analysis whether and how the variations in the occlusion due to the correction of the posterior crossbite using a rapid palatal expander (RPE) is accompanied by changes in the activity of the elevator muscles in the pediatric patients. Background Posterior crossbite is a disgnathic jaw relationship common in patients undergoing growth. In the last 10 years, several studies demonstrated the effectiveness and reproducibility of surface EMG in the objective evaluation of temporal muscle and masseter activity and how this evidence can be an interesting aid in dental clinical practice. Case description The case subject BF is an 11-year-old boy with a right I class relationship and a left II class relationship treated with a rapid palatal expansion protocol with a turn of the transversal screw twice a day (0.25 mm each turn) for a week. In this case report, EMG was used to evaluate the temporal muscle and masseter activity immediately before, immediately after, and 4 months after the RPE protocol. Conclusion Four months after the treatment, a condition of well-being and neuromuscular equilibrium such as that of starting was preserved. Clinical significance Electromyography is a noninvasive exam which evaluates the masticatory muscle activity by facial application of electrodes on masseter and temporal muscles. It can be an interesting aid in orthodontic clinical practice to evaluate preservation of a good muscular balance following orthodontic and orthognathic movements. How to cite this article Maddalone M, Nanussi A, Varisco M, et al. Electromyographic Evaluation of Masticatory Muscles in a Young Patient with Crossbite Treated with Rapid Palatal Expander: A Case Report. J Contemp Dent Pract 2020;21(11):1279–1283.

Objective: To investigate the action of osteopathic manipulative treatment on the muscular activity of the stomatognathic apparatus by using surface electromyography (sEMG). Material and Methods: Surface electromyography (sEMG) was performed on the masseter and anterior temporalis muscles of 120 subjects (73 F, 47 M), both at time T0 and T2. The sample was divided into three randomized groups of 40 subjects each: control, placebo, and osteopathic manipulative treatment (OMT). In the T1 interval between the two evaluations, the control group was not treated, the placebo group underwent a placebo treatment, and the OMT group underwent manipulative treatment. The mean value of each measurement and its coefficient of variation, between time T0 and T2, were calculated for both the intragroup (OMT, placebo, control) and the intergroup (OMT-placebo, OMT-control). Outcomes: In 40% of the subjects, statistically significant improvements were highlighted in the OMT. Whereas, the statistically significant results of the placebo and control groups were 7.5% and 17.5%, respectively, of which more than 75% moved away from the physiological range, showing a worsening of the muscular activity. This analysis showed statistically significant variations (p &le, 0.05) in the OMT group compared to the placebo and the control groups. Conclusions: OMT determines variations of the activity of masticatory muscles.

Aim of study: No evidence is found in literature to assess that malocclusion can lead to postural or craniocervical–mandibular disorders. The aim of this study is to investigate with surface electromyography (EMG) of masticatory muscles and stabilometric analysis the relationship between malocclusion and presence of temporomandibular disorders (TMDs) or postural variations in a group of athletes of different sports. Materials and methods: Seventy-four athletes belonging to different sport societies were included in this study. Chi-square test, taking as significance index χ​2 > 0.05, was used to compare in pairs the postural interference, muscle disharmony, malocclusion, and TMDs. Results: No statistical significance emerged, correlating postural interference and muscle disharmony (χ​2 = 0.15), muscular imbalance, and anatomical findings of malocclusion (χ​2 = 0.62), muscular imbalance and TMDs (χ​2 = 0.15), and TMDs and malocclusion (χ​2 = 0.09). Statistically significant association [χ​2 = 0.019, odds ratio (OR) = 3.10] emerged from the correlation between TMDs and postural interference. Conclusion: A correlation between posture and occlusion is very difficult to be demonstrated. A multidisciplinary approach is required for TMDs: therapy with oral splints allows to give greater compliance to the system by allowing muscles to guide the jaw in a position of functional equilibrium. Clinical significance: Gnathological treatment evaluated through EMG and stabilometric platform allows to obtain improvements in the occlusal balance.

Aim: The aim of this work was to evaluate if the use of a silicone device for muscular rebalancing (Alifix®) can be useful in treating of temporomandibular disorders (TMD) of muscular origin and improving the electromyographic indexes of the chewing muscles. Materials and methods: Thirteen patients (11 F and 2 M aged between 24 years and 65 years) with TMD of muscular origin according to diagnostic criteria (DC)/TMD were involved. At the first visit (T0), each patient reported the pain intensity of masseters and temporal muscles. A surface electromyography (EMG) was performed using Teethan® (Teethan S.p.A.) and then Alifix® was delivered instructing the patient on its use. Each subject was visited again after 1 month (T1) and 2 months (T2). New EMG had been made at T1 and T2, and patients were asked again to report the pain intensity. Statistical analysis was calculated between T0 and T1, T1 and T2, and T0 and T2 for all EMG, and muscle pain measurements by Wilcoxon test with statistical significance p < 0.05. Results: Regarding the pain values between T0 and T1, T1 and T2, and T0 and T2, the difference is statistically significant, since the intensity of pain between T0 and T2 is decreased, if not disappeared, in 90% of cases. The use of Alifix® also determined a gradual improvement in the values of the EMG indexes, which, however, is not statistically significant. Conclusion: The effectiveness of Alifix® is demonstrated clinically but not at an instrumental level. Further studies involving a larger sample and taking longer therapy duration are needed. Clinical significance: Alifix® works by improving the blood circulation of the muscle, which allows the removal of catabolites with a consequent reduction of the algic symptomatology and promotes a greater supply of oxygen. It also encourages a conversion of IIA type muscle fibers into slow-twitch type I fibers that are more resistant to neuromuscular fatigue