Regional volumetric change of the tongue during mastication in pigs

Abstract

Structure and movement of the tongue have been studied extensively, but little study has been carried on its 3D deformation and ensuing volumetric changes during various functions. The purpose of this study is to investigate the volumetric changes of a regional section of the tongue during feeding. Four 12-week-old Yucatan miniature pigs were used. During natural mastication and water drinking, the width, length, thickness and volumetric changes were measured using six implanted ultrasonic crystals, which circumscribed a wedge-shaped volume in the region of the tongue body. Jaw movements were videotaped and digitized. Signals from these two sources were synchronized to allow real-time analyses. Significant volumetric changes (P < 0.001) were found in chewing, ingestion and drinking, and these changes were stereotypical in relation to rhythmic jaw movements. Volumetric change during chewing was not only more regular, but significantly larger (45.6%, P < 0.001) than that during ingestion (31.4%). The volumetric changes were less regular in drinking and the changing range (30.4%) was close to that during ingestion. Real-time analysis indicated that the volume began increasing at late jaw closing and reached the peak at late power stroke. The increase in duration of volume only took up 33.4% of the total chewing cycle length; significantly shorter than that of volume decrease. Correlation analysis revealed that the change in posterior dorsal and ventral widths had the greatest positive association with volumetric change (r = 0.43) in direction. The covariance calculations further indicated that dimensional changes in length and thickness coupled negatively with volumetric changes in amplitude. These results revealed that regional volumetric change of the tongue occurs during feeding and chewing requires larger volumetric changes than do ingestion and drinking. Volumetric expansion occurs in the phase of power stroke during chewing and is coupled with increases in widths in the direction and with decreases of thickness and length in the amplitude. The results further suggested that the regional volumetric expansion may play the determinant role in functional load production on its surrounding tissues, and may also imply that neuromuscular control of the tongue is region-specific, a notion incompatible with traditional scheme of categorizing muscle function in the tongue.

A Dual-Mode Magnetic–Acoustic System for Monitoring Fluid Intake Behavior in Animals

“…Table I summarizes the statistical results for all four mini-pigs tested 2 or 3 times each with the MAFIM system. These results are consistent with earlier reports of drink behavior in adult mini-pigs [2], [38], [39]. Regression analysis confirmed agreement ( R 2 = 0.98, t=0.4, p=0.7) among LCDs extracted from the acoustic and magnetic modalities for a sample of 10 random drink measurements from in vivo experiments.…”

Animal Models for Dysphagia Studies: What Have We Learnt So Far

“…Higher imaging speeds, 100–500 frames per second, are possible in animals, as compared to the 30 or 60 fps in human studies. Animal studies can have implanted radio-opaque markers that permit detailed kinematic analyses of tongue movements not possible humans [5, 14, 31]. …”

Magnetic implants in the tongue for assistive technologies: Tests of migration; oromotor function; and tissue response in miniature pigs

“…By electromyography and sonomicrometry drink cycles of ~2.25–2.5 Hz were reported in adult mini-pigs drinking from open containers (Figure 19, (Herring & Scapino, 1973); Figure 6, (Liu, et al, 2008)). In our study, average drink cycle, recorded in magnetic and auditory modalities for each mini-pig, ranged from 3.21–3.88 Hz.…”

“…Therefore, to limit the study to cycles of drinking, we analyzed data for which the time from ball-down to subsequent ball-down (i.e., a drink cycle duration) was from 0.205 to 0.5 s (mini-pigs drink from an open container at ~2.25–2.5 Hz, see (Herring & Scapino, 1973),(Liu, Yamamura, Shcherbatyy, & Green, 2008) (Liu, Shcherbatyy, Kayalioglu, & Seifi, 2009); infant pigs suck from a bottle at ~ 4 Hz (Holman et al, 2013)). Impact of experimental procedures on drink dynamics was assessed by comparing modal drink cycle rate (DCR, expressed in hertz) measured by magnetic and by auditory modalities from one to fourteen days before and from eight to fifteen days after successful implantation and explantation procedures.…”