Background

Muscle-related temporomandibular disorders (TMD) may affect the masticatory function. Chewing function can be assessed objectively using bolus kneading tests, such as two-color chewing gum mixing ability test.

Objective

The aim was to compare the masticatory function with a two-color chewing gum test before and after treatment of the masticatory muscle-related temporomandibular disorder.

Methods

Twenty-one patients with masticatory muscle disorder according to Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) were recruited as an experimental group, and further twenty-one participants without any TMD were included as controls. Pain intensity (scored on a visual analog scale) and maximum mouth opening (MMO) were recorded. Jaw Functional Limitation Scale-8 (JFLS-8) was conducted on all patients. Before and after treatment, masticatory function was evaluated with a validated bolus-kneading test, using two-color chewing gum.

Results

There was no statistically significant difference in chewing function before and after treatment in the experimental group (p=0.715). When these values were compared with the control group, there were no statistically significant differences (p=0.489, p=0.890). There was no correlation between masticatory function and VAS, MMO, JFLS-8 before and after treatment in the experimental group.

Conclusion

The two-color chewing gum test is not sensitive when the masticatory performance is not severely impaired.