Effects of gum chewing training on occlusal force, masseter muscle thickness and mandibular shape: A randomised controlled clinical trial

Abstract

BackgroundMasticatory muscle training by chewing gum can be performed easily and improve masticatory muscle function and strength. However, increased masticatory muscle activity and function may alter the mandibular shape. ObjectiveWe aimed to investigate the effects of gum chewing training on the occlusal force, masseter muscle thickness (MMT) and mandibular shape in healthy adults. MethodsWe conducted a prospective randomised controlled trial from January 2020 to September 2020 at the Yonsei University College of Dentistry. Fifty-eight participants were randomly assigned to the training and control groups. The training group chewed gum three times a day for 6 months, while the control group received no training. Changes in the maximum occlusal force and MMT were evaluated at baseline and after 1, 3 and 6 months. Changes in the mandibular shape were evaluated at baseline and after 6 months. ResultsThe mean maximum occlusal force of the training group at 3 months was significantly higher than that at baseline, which was also significantly different from that in the control group (p < .001). As the maximum occlusal force increased, the occlusal contact area also increased (p = .020). There was no statistically significant difference in MMT or mandibular shape compared to the baseline. ConclusionMastication training using gum increases maximum occlusal force due to an increase in occlusal contact area but has no effect on MMT or mandibular shape.