Study of jaw movement and masticatory muscle activity during unilateral chewing with and without balancing side molar contacts.

This research evaluated the relationship between balancing side molar contacts and chewing patterns measured with a jaw movement analyser and multi-channel electromyography (EMG) of the masticatory muscles. Nine healthy subjects with relatively normal occlusions participated in the experiment and were divided into those with balancing side molar contacts and those without. The block gum chewing task was performed on each side of the mouth for 10 s. The results showed more asymmetrical levels of jaw closing muscle activity during unilateral chewing in the group with balancing side molar contacts when compared with the group without these contacts.