Short-Term Effect of Orthodontic Treatment with Clear Aligners on Pain and sEMG Activity of Masticatory Muscles

• Main Authors: Alessandro Nota, Silvia Caruso, Shideh Ehsani, Gianmaria Fabrizio Ferrazzano, Roberto Gatto, Simona Tecco
• Format: Article
• Language: English
• Published: MDPI AG 2021-02-01
• Series: Medicina
• Subjects: interceptive orthodontics; removable orthodontic appliances; electromyography; masticatory muscles; orthodontics
• Online Access: https://www.mdpi.com/1010-660X/57/2/178

<i>Background and objectives:</i> The aim of this study is to evaluate mandibular elevator muscles activity and pain on palpation in the early stages of orthodontic treatment with clear aligners using surface electromyography (sEMG). <i>Materials and methods:</i> Surface electromyography (sEMG) activity and pain level on muscle palpation of masseter and anterior temporalis muscles were recorded in a sample of 16 adult subjects (aged 18–32 years; mean 22.5 +/− 3.5 SD) undergoing orthodontic treatment with clear aligners before the treatment (T0), after 1 month of treatment (two clear aligners) (T1), and after 3 months of treatment (T2) (six clear aligners). A chi-square test for nominal data, a Friedman test, and a Wilcoxon-signed rank test as post hoc analysis were applied. <i>Results:</i> No statistically significant differences in muscular pain were observed. At T1, the sEMG activity of masseter muscles at mandibular rest position showed a statistically significant reduction, but after 3 months (T2), the data appeared similar to T0 (<i>p</i> = 0.03 and <i>p</i> = 0.02). <i>Conclusions:</i> During the treatment with clear aligners, subjects could experience an initial reduction in the masseter basal activity after 1 month of treatment. This effect tends to decrease to baseline levels after 3 months of therapy.