Journal of dental research
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Human individuals were hypothesized to use the same pattern of jaw muscle activity to produce the same bite force. To test this hypothesis, we used a 2-mm-thick force transducer to monitor the magnitude and direction of a bite force between a single pair of occluding first molars. Five subjects performed standardized bite force tasks. ⋯ In contrast, when the magnitude of bite force was the same but the directions were different, the ratio was not constant. We conclude that the direction of a bite force, not its magnitude, determines the pattern of activity of jaw-closing muscles. The shared patterns of muscle activation may be the result of a subconscious optimization of jaw muscle forces to improve efficiency.