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

Background: Masticatory 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.

Objective: We aimed to investigate the effects of gum chewing training on the occlusal force, masseter muscle thickness (MMT) and mandibular shape in healthy adults.

Methods: We 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.

Results: The 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.

Conclusion: Mastication training using gum increases maximum occlusal force due to an increase in occlusal contact area but has no effect on MMT or mandibular shape.