Jaw kinematics and tongue protraction–retraction during chewing and drinking in the pig

Abstract

Mastication and drinking are rhythmic and cyclic oral behaviors that require interactions between the tongue, jaw, and a food or liquid bolus, respectively. During mastication, the tongue transports and positions the bolus for breakdown between the teeth. During drinking, the tongue aids in ingestion and then transports the bolus to the oropharynx. The objective of this study is to compare jaw and tongue kinematics during chewing and drinking in pigs. We hypothesize there will be differences in jaw gape cycle dynamics and tongue protraction-retraction between behaviors. Mastication cycles had an extended slow-close phase, reflecting tooth-food-tooth contact, whereas drinking cycles had an extended slow-open phase, corresponding to tongue protrusion into the liquid. Compared to chewing, drinking jaw movements were of lower magnitude for all degrees of freedom examined (jaw protraction, yaw, and pitch), and were bilaterally symmetrical with virtually no yaw. The magnitude of tongue protraction-retraction (Txt), relative to a mandibular coordinate system, was greater during mastication than drinking, but there were minimal differences in the timing of maximum and minimum Txt relative to the jaw gape cycle between behaviors. However, during drinking, the tongue tip is often located outside the oral cavity for the entire cycle, leading to differences between behaviors in the timing of anterior marker maximum Txt. This demonstrates that there is variation in tongue-jaw coordination between behaviors. These results show that jaw and tongue movements vary significantly between mastication and drinking, which hint at differences in the central control of these behaviors.

Twist and chew: three-dimensional tongue kinematics during chewing in macaque primates

“…Posterior tongue roll and yaw play little role in overall tongue rotation during chewing in macaques, presumably because the back of the tongue is anchored to the hyoid bone, palatoglossus, styloglossus and hyoglossus. Middle tongue roll and long axis flexion also appear to occur during chewing in pigs and may explain regional changes in tongue lengths and widths [ 14 , 15 ].…”

“…The recent development and dissemination of the X-ray reconstruction of moving morphology (XROMM) workflow for analysis and visualization of biplanar videoradiographic data [ 12 , 13 ] makes it possible to quantify 3D tongue shape and position using small spherical tantalum bead implants [ 6 , 14 – 16 ]. To date, detailed descriptions of high-resolution 3D tongue kinematics have been limited to measures of tongue protraction, retraction, width and length during chewing and drinking in pigs [ 14 , 15 , 17 ]; data on tongue flexion and roll, and tongue kinematics during chewing in a non-human primate model of human feeding have not been presented. Here, we report XROMM-based quantification of 3D tongue kinematics during mastication in macaque primates and document their relationships to simultaneous mandible movements.…”

Lip service: Histological phenotypes correlate with diet and feeding ecology in herbivorous pacus

“…We propose that in other characiform fishes like pacus, bryconids, and alestids (Datovo & Castro, 2012), the morphology of the primordial ligament has been selected for different functional roles depending on the size, shape, and surface texture of prey. The importance of soft tissues for prey handling cannot be overstated-without a tongue to reposition the bolus, mammalian mastication would not be nearly as efficient as it is (Gintof et al, 2010;Hiiemae & Palmer, 2003;Olson et al, 2021). Likewise, the interaction of a ductile lip opposite a hard dentition is a useful arrangement for gripping slippery objects (Barlow & Munsey, 1976).…”

Progressive Protrusive Tongue Exercise Does Not Alter Aging Effects in Retrusive Tongue Muscles

“…While rat models of oromotor functions are invaluable for translational research ( German et al, 2017 ), it should be noted that some intrinsic differences in tongue function between rats and humans may impose certain limitations on the translational applicability of this study. Depending on the species and the context, the ways mammals use the tongue on a daily basis can vary in the magnitude of protrusive tongue movements and retrusive tongue movements ( Olson et al, 2021 ). Notably, while humans typically drink with their tongue positioned intraorally ( Matsuo and Palmer, 2008 ), rats typically drink by protruding the tongue from the oral cavity while licking or lapping ( Weijnen, 1998 ).…”