Meeting Abstract
A fundamental component of mammalian feeding is mastication, involving occlusion of postcanine teeth to finely break down food into smaller particles. The dynamics of occlusion have primarily been inferred from surface features of the teeth, including occlusal topography and wear patterns. Recently, however, X-Ray Reconstruction of Moving Morphology (XROMM) provides the visualizing and measurement resolution necessary to characterize the dynamics of occlusion during chewing. Here, we use XROMM to investigate the effect of two food properties, stiffness and toughness, on molar occlusion during rhythmic chewing in pigs. Four pigs were fed size standardized pieces of apple (low toughness and low stiffness), carrot (high toughness and low stiffness), and almond (high toughness and high stiffness). We compared the duration of the occlusal period as well as the translations in the buccolingual, mesiodistal, and ventral-dorsal planes of individual cusps. Mixed effects modeling with repeated measures on individuals demonstrated that toughness and stiffness differentially impact occlusal dynamics. Increasing food toughness results in longer tooth-food-tooth or tooth-tooth contact during chewing, but there was no change associated with increased food stiffness. Translations of the first molar were observed in the mesiodistal plane across foods of different toughness while buccolingual displacements were different among foods of different stiffness. These results may reflect that low toughness foods require less tooth-food-tooth contact to facilitate bolus creation, whereas foods of different stiffness impact other measures of the gape cycle (i.e., translations).
