Comparison of jaw tracking by single video camera with 3D electromagnetic system

• A simple single camera 2D video jaw tracking system is evaluated.
• Gives similar ranking of chewing parameters for 4 model food gels as incisor tracking.
• Suitable for measuring large numbers of subjects for consumer studies.

The breakdown of food during chewing is both a physical process and a sensory experience. In trying to understand the differing sensory responses of consumers to food products it is useful to be able to measure their physical chewing action. In this paper we report the results of a comparison between a simple 2D video jaw tracking method with a 3D method using the JT-3D™ Jaw Tracker (BioRESEARCH Assoc., Inc., Milwaukee), on four model gel systems. The video and JT3D systems gave similar values for number of chews, chewing time, chewing cycle time, chewing frequency, opening velocity, and proportion of crossed/crescent/circle shaped cycles. Although timing of the three phases of a chew and vertical and lateral movement were different between the two methods, the effect of the different model gels on these parameters are similar in direction by the two methods for vertical and lateral movement, and opening and closing velocity and closing time. Our study demonstrates that for sensory evaluation of foods and consumer preference, where large numbers of participants are required to cover the variation in human populations, the simple 2D video method allows jaw movement to be tracked with sufficient accuracy to detect the effects produced by different foods.