Related Experiment Video
Updated: Aug 2, 2025
Author Spotlight: 3D Movement Assessment of Maxillary Posterior Teeth in Clear Aligner Treatment
Published on: February 23, 2024
Response of masticatory muscles to treatment with orthodontic aligners: a preliminary prospective longitudinal study
Sylvia de Araújo Paes-Souza1, Marco Antonio Cavalcanti Garcia2, Victor Hugo Souza3
1Universidade Federal do Rio de Janeiro, Departamento de Odontopediatria e Ortodontia, Programa de pós-graduação em Odontologia (UFRJ, Rio de Janeiro/RJ, Brazil).
Introduction:
The emergence of orthodontic aligners has provided an aesthetic and comfortable option for orthodontic treatment. However, the encapsulated design of the aligners can influence the masticatory muscles, and might compromise safe treatment.
Objective:
This preliminary longitudinal study aimed to investigate whether the use of orthodontic aligners affects the biting force and myoelectric activity of the superficial masseter and anterior temporal muscles.
Methods:
Ten subjects participated in the study and underwent treatment during an 8-month follow-up period. The root mean square (RMS), the median power frequency (MPF) of the surface electromyography (sEMG) signals, and the biting force (kgf) were recorded and normalized relative to the pretreatment condition. The data were analyzed by repeated-measure analysis of variance (ANOVA), with the significance level set at 5%.
Results:
Both the superficial masseter and the anterior temporal muscles presented an increase in sEMG signal activity during the treatment, with a marked increase in the latter compared to the former (p<0.05). Moreover, a significant decrease in bite force was evidenced (p<0.05).
Conclusions:
This preliminary study observed that the orthodontic aligners affected the muscle recruitment pattern of masticatory muscles, and reduced biting performance during the 8-month follow-up period.
