Fig 6. Development of contact areas during power stroke simulations and proposed chewing models.

Left: Stacked bar charts comparing the development of wear facet areas for power stroke simulations conducted using the Occlusal Fingerprint Analyser software package. Each collision is broken down into a series of timesteps in which the lower tooth model attempted to move 0.05mm towards the next point along the estimated power stroke movement trajectory. The software calculates any collisions that occur between the opposing teeth at each time step. One individual was selected from the medieval period (SK2033 from York Barbican) and one individual from the industrial period (SK1010 from Coronation Street). The medieval individual showed an extended power stroke relative to the industrial individual and a more clearly defined and extended period of exclusively phase II contacts. Right: Visualisation of the hypothesized differences between the chewing cycles of individuals from the industrial and pre-industrial group.