OWN - Quintessenz Verlags-GmbH CI - Copyright Quintessenz Verlags-GmbH OCI - Copyright Quintessenz Verlags-GmbH TA - JT - Journal of Aligner Orthodontics IS - 2514-7560 (Electronic) IS - 2514-7552 (Print) IP - 1 VI - 5 PST - ppublish DP - 2021 PG - 33-38 LA - en TI - Masticatory muscle activity during clear aligner therapy in young adults: a pilot study FAU - Casasco, Federica AU - Casasco F FAU - Nebiolo, Bianca AU - Nebiolo B FAU - Tassi, Ali AU - Tassi A FAU - Cioffi, Iacopo AU - Cioffi I FAU - Castroflorio, Tommaso AU - Castroflorio T CN - OT - active aligner OT - clear aligner therapy OT - dummy aligner OT - masticatory muscle activity OT - surface electromyography OT - young adults AB - Objective: The aim of this pilot study was to measure the activity of the masseter in young adults treated with clear aligner therapy using ambulatory electromyography.  Materials and methods: The electromyographic activity in the right masseter muscle of 6 young adults (3 female, 3 male, 18.8 ± 4.3 years) undergoing clear aligner therapy over 4 weeks (week 1 baseline without aligners [T0], week 2 with a dummy passive aligner [T1], week 3 with the first active aligner [T2] and week 4 with the second active aligner [T3]) was recorded using portable electromyographic data loggers. A mixed-effects model was used to test differences in surface electromyographic activity over the four experimental conditions.  Results: The surface electromyographic activity of the masseter increased significantly with aligners compared to baseline. It also increased significantly from T0 to T1 (P < 0.001), and increased from T1 to T2 (P = 0.024). There was no statistically significant difference between T2 and T3 (P = 0.799).  Conclusions: Clear aligner therapy in young adults is associated with an increase in masticatory muscle activity, possibly due to an increase in parafunctional tooth clenching. AID - 1129639