Tongue Marker Research Articles

Tongue and jaw movement assessed by 3D motion capture during gum chewing.

The tongue plays an important role in mastication, swallowing, and articulation, but it cannot be directly observed because of its location inside the oral cavity. This study aimed to clarify detailed 3D tongue movements during chewing using electromagnetic articulography (EMA). The participants were 10 healthy, young volunteers (average age 26.8 ± 2.1years; 5 males, 5 females). Tongue and jaw movement during gum chewing was measured and recorded using EMA. Four EMA sensors were attached to the anterior, posterior, left, and right surfaces of the tongue, and one sensor was also attached to the mandibular left incisor. The tongue motion during the chewing cycle was spatially and sequentially analyzed based on the motion trajectories of the tongue and mandible. The tongue moved downward and to the masticatory side in a manner similar to the movement of the jaw. The anterior tongue marker moved downward to a greater extent than the other tongue markers. However, the tongue moved forward as the jaw moved backward. The anterior marker reached the most anterior position during the jaw-opening phase and the posterior markers reached the most anterior position during the jaw-closing phase. Just before maximum jaw-opening, all markers on the tongue reached the bottom lowest position. During the jaw-closing phase, the tongue reached the dominant farthest position in the masticatory side. All the markers reached the most posterior position during the occlusal phase. These findings demonstrate the sequence of tongue motion patterns during gum chewing.

Kinematics of lateral tongue-pushing movement in coordination with masticatory jaw movement: An anteroposterior projection videofluorographic study

ObjectiveDuring the mastication of solid food, the tongue pushes the bolus laterally to place it onto occlusal surfaces as the jaw is opened. This movement is referred to as tongue-pushing (TP). TP has an important role in efficient chewing, but its kinematic mechanisms remain unclear. The present study quantified the kinematics of TP and its coordination with masticatory jaw movements. MethodsVideofluorography (VFG) in anteroposterior projection was recorded while 14 healthy young adults ate 6 g each of cookies and meat. Small lead markers were glued to the tongue surface (left, right, and anterior) and buccal tooth surfaces (upper molars and lower canines). The position of the tongue and lower canine markers relative to the upper occlusal plane was quantified with Cartesian coordinates, using the right upper molar as the origin. Jaw motion during chewing was divided into TP and Non-TP cycles, based on the lateral movement of the food and tongue markers. The side of the jaw that compressed food particles was defined as the working side, while the other side was termed the balancing side. Horizontal and vertical displacements of tongue and jaw markers were compared between TP and Non-TP cycles, as well as between food types. ResultsThe mediolateral displacement of all tongue markers was significantly larger in TP than in Non-TP cycles. Vertical displacement was also significantly greater in TP than in Non-TP cycles for the anterior and working side tongue markers. TP cycles occurred more frequently with meat-chewing than with cookie-chewing. ConclusionTP is accomplished by rotation and lateral movements of the tongue surface on the working side and the anterior tongue blade, along with medial movement on the balancing side. These movements produce lateral shift and rotation of the tongue surface toward the working side in concert with jaw opening. Designing exercises to improve the strength of the lateral motion and rotation of the tongue body may be useful for individuals with impaired tongue function for eating and swallowing.

3D hyoid and tongue kinematics reveal mechanism of tongue base retraction during swallowing in Didelphis virginiana

In anthropoid primates, tongue base retraction (TBR) is a key event for airway protection and bolus propulsion during swallowing. In macaques, hyoid protraction and elevation during swallowing reduce the oral volume and squeeze the tongue base to retract. This novel hyoid-powered hydraulic TBR mechanism implies that the morphology and position of the hyoid are functionally relevant for TBR performance. However, macaque’s highly derived craniofacial and hyoid morphology precludes inference on the evolutionary history and driving mechanism of TBR across mammal phylogeny at large. Here we use biplanar videoradiography and the XROMM workflow to infer TBR mechanism in Didelphis virginiana through high-resolution 3D hyolingual kinematics. Similar to macaques, Didelphis has an incomplete hyoid cornu, which would enable a large hyoid range of motion that facilitates oral volume reduction. Unlike macaques, Didelphis hyoid has a more posteriorly resting hyoid position. We predict that TBR will occur in Didelphis through a similar hyoid-powered hydraulic mechanism. We find Didelphis deploys TBR during the first opening (O1) phase (liquid) or slow-open phase (solid) of jaw cycle with retraction and elevation of midline posterior tongue markers. Minimal retraction occurs in lateral tongue markers where extrinsic lingual muscles insert. The tongue base and posterior tongue are lengthening, narrowing and increasing in height during TBR, consistent with predictions based on muscular hydrostat model. The tongue base was not isovolumetric during TBR, but the volume change was orders of magnitude smaller than that observed in macaques. Hyoid protraction and elevation occur before and continue throughout TBR, which strongly suggest concurrent reduction of oral volume as well. Our preliminary data suggest the TBR mechanism in opossums may differ in important ways from that utilized by macaques, where opossums could employ a combination of hydrostatic deformation and hydraulic mechanism to drive retraction of tongue base. We provide novel insights into the conservation of TBR across therian mammals and extend our understanding on the form-function relationships between the hyolingual apparatus and swallowing biomechanics. Hinds Fund, University of Chicago This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Shape change throughout the body of the tongue during drinking in the striped skunk (Mephitis mephitis)

In mammals, the tongue plays a central role in many oral behaviors, but it is particularly essential for feeding and drinking. During feeding, the tongue is used for ingestion, manipulation and positioning of food within the oral cavity, and swallowing. When mammals drink, they do so by lapping, licking, or sucking, and the tongue is vital to uptake and transport of fluid into and through the oral cavity and oropharynx. All of these behaviors are performed with only a partial reliance on a bony support system; instead the tongue engages in complex movements as a muscular hydrostat – where selective contraction of intrinsic and extrinsic muscle fibers produce movements and deformations of the tongue. The tongue's anatomical complexity and its location inside the oral cavity make it particularly difficult to visualize and study the movements that contribute to these and other oral behaviors. The objective of this study is to test the ability of marker‐based XROMM (X‐ray reconstruction of moving morphology) to track shape changes throughout the body of the tongue. The striped skunk (Mephitis mephitis), a mammalian omnivore belonging to the order Carnivora, was used as a model for rhythmic lapping while drinking a barium liquid. Data was collected using XROMM with markers implanted in the bones of the skull as well as in the body of the tongue. Tongue markers were used to calculate length changes throughout the body of the tongue. Timing and movement parameters are also registered to the gape cycle derived from the rigid body motions derived from skeletal markers. Based on an analysis of 150 cycles, during rhythmic drinking, the middle and posterior tongue underwent the most variation in length change, while the anterior tongue underwent the least amount of variation in length. In contrast, the posterior tongue underwent the least amount of variation in tongue width, as compared to the anterior and middle tongue. Maximum overall tongue length occurred 2.74±29.3 msec before maximum gape, whereas minimal overall tongue length occurred 20.24±7.38 msec before minimum gape. Based on these preliminary results, this method shows promise for producing quantitative data for studying tongue deformations within the oral cavity. Future studies incorporating spatial parameters of the tongue to the rest of the feeding apparatus across mammals will further our understanding of how the tongue functions during feeding and drinking behaviors.Support or Funding InformationNational Science Foundation Grant DBI‐0922988, National Science Foundation Grant IOS‐1456810This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Expression of DMP1 in the developing mouse tongue embryo

Dentin matrix protein 1 (DMP-1) is an important factor in the mineralization of hard tissues. However, it has many other functions in addition to the regulation of mineralized tissues. We analyzed the expression and localization of DMP-1 by immunohistochemical staining and in situ hybridization in the developing mouse tongue during embryonic days 12.5 (E12.5), E14.5, E17.5, and E18.5. We also detected the mRNA abundance of tongue morphogenesis markers such as FGF6, TGF-β1, Collagen I, osteocalcin, chondromodulin 1, tenomodulin, Vascular endothelial growth factor (VEGF), caspase-3, and Aifm from embryonic stages by real-time RT-PCR. The antisense probe for DMP-1 was detected in a few mesenchymal cells surrounding blood vessels at E12.5, and faint localization was seen at E18.5 in the embryonic mouse tongue by in situ hybridization. The DMP-1 and osteocalcin abundance levels gradually increased compared with the other tongue markers from E12.5 to E18.5 (p<0.001). Cluster analyses identified the following distinct clusters for mRNA abundance in the tongue: cluster 1, E12.5; cluster 2, E14.5 and E17.5; and cluster 3, E18.5. The positive correlation between DMP-1 and osteocalcin (Pearson's r=0.685; p<0.05) and negative correlation between DMP-1 and Caspase-3 (Pearson's r=-0.632; p<0.05) were analyzed. These data suggested that DMP-1 potentially influences osteocalcin and Caspase-3 during mouse tongue development and morphogenesis. DMP-1 also affects the angiogenic marker VEGF in specific stages and areas, terminating the differentiation of the tongue from other developing tissues. We conclude that DMP-1 may be involved in regulating the temporal expression at embryonic stages in the mouse tongue.

Tongue width at rest versus tongue width during speech: A comparison of native and non-native speakers

Most pronunciation researchers do not focus on the coronal view. However, it is also important to observe because the tongue is hydrostatic. We believe that some pronunciation differences between native speakers and second-language (L2) speakers could be due to differences in the coronal plane. Understanding these differences could be a key to L2 learning and modeling. It may be beneficial for pedagogical purposes and the results of this research may contribute to the improvement of pronunciation of L2 English speakers. An interesting way to look at native and L2 articulation differences is through the pre-speech posture and inter-speech posture (ISP—rest position between sentences). In this research, we compare native speakers to L2 speakers. We measure how different those postures are from the median position of the tongue during speech. We focus on movement of a side tongue marker in the coronal plane, and we normalize for speaker size. We found that the mean distance from pre-speech posture to speech posture is shorter for native English speakers (0.95 mm) than for non-native English speakers (1.62 mm). So, native speakers are more efficient in their pre-speech posture. Results will also be shown for distances from ISP to speech posture.

Coarticulatory effects of lateral tongue bracing in first and second language English speakers

This study uses electromagnetic articulometry (EMA) to examine the coarticulatory effects of tongue bracing in L1 and L2 English speakers. The tongue is hydrostatic, so we brace it against our teeth for added control, and this bracing is an important part of pronunciation. The amount of bracing may differ across languages (and may be part of one’s articulatory setting), so understanding these differences could be a key to L2 pronunciation learning. Although lingual coarticulation has been examined using acoustics and midsagittal views of the vocal tract, not much focus has been placed on the coronal view. We collected EMA point-tracking data from two native speakers of North American English and looked at the movement of a lateral tongue marker. As stimuli, we choose the nursery rhyme “Mary had a Little Lamb” because of the variation in vowels, and also the /l/ and /r/ phonemes, which are absent in Japanese. Initial results show differences between vowels that occur next to /l/ and those that occur next to /r/ and stops. Results will also be presented for Japanese speakers of both their L1 (Japanese) and L2 English. If we find crosslinguistic differences in bracing, this fact will be important for pedagogical purposes.

Kinematic Analysis of the Oral Propulsive Phase in Swallowing using Videofluoroscopy with Tongue Markers

Kinematic Analysis of the Oral Propulsive Phase in Swallowing using Videofluoroscopy with Tongue Markers

Fluoroscopic Evaluation of Tongue and Jaw Movements During Mastication in Healthy Humans

When chewing solid food, part of the bolus is propelled into the oropharynx before swallowing; this is named stage II transport (St2Tr). However, the tongue movement patterns that comprise St2Tr remain unclear. We investigated coronal jaw and tongue movements using videofluorography. Fourteen healthy young adults ate 6 g each of banana, cookie, and meat (four trials per foodstuff). Small lead markers were glued to the teeth and tongue surface to track movements by videofluorography in the anteroposterior projection. Recordings were divided into jaw motion cycles of four types: stage I transport (St1Tr), chewing, St2Tr, and swallowing. The range of horizontal tongue motion was significantly larger during St1Tr and chewing than during St2Tr and swallowing, whereas vertical tongue movements were significantly larger during chewing and St2Tr than during swallowing. Tongue movements varied significantly with food consistency. We conclude that the small horizontal tongue marker movements during St2Tr and swallowing were consistent with a "squeeze-back" mechanism of bolus propulsion. The vertical dimension was large in chewing and St2Tr, perhaps because of food particle reduction and transport in chewing and St2Tr.

Automatic tongue image segmentation based on gradient vector flow and region merging

This paper presents a region merging-based automatic tongue segmentation method. First, gradient vector flow is modified as a scalar diffusion equation to diffuse the tongue image while preserving the edge structures of tongue body. Then the diffused tongue image is segmented into many small regions by using the watershed algorithm. Third, the maximal similarity-based region merging is used to extract the tongue body area under the control of tongue marker. Finally, the snake algorithm is used to refine the region merging result by setting the extracted tongue contour as the initial curve. The proposed method is qualitatively tested on 200 images by traditional Chinese medicine practitioners and quantitatively tested on 50 tongue images using the receiver operating characteristic analysis. Compared with the previous active contour model-based bi-elliptical deformable contour algorithm, the proposed method greatly enhances the segmentation performance, and it could reliably extract the tongue body from different types of tongue images.

Kinematic linkage of the tongue, jaw, and hyoid during eating and speech

Tongue movement is temporo-spatially coordinated with jaw and hyoid movements during eating and speech. As such, we evaluated: (1) the correlation between the tongue with jaw and hyoid movements during eating and speech and (2) the relative influence of the jaw and hyoid on determining tongue movement. Lateral projection videofluorography was recorded while 16 healthy subjects ate solid foods or read a standard passage. The position of anterior and posterior tongue markers (ATM and PTM, respectively), the jaw, and the hyoid relative to the upper occlusal plane was quantified with the upper canine as the origin (0,0) point for Cartesian coordinates. For vertical and horizontal dimensions, separate multiple linear regression analyses were performed with ATM or PTM position as a function of jaw and hyoid positions. Vertically, both ATM and PTM positions were highly correlated with the jaw and hyoid during eating (median r=0.87). The relative influence was higher for the jaw than the hyoid for ATM position (P<0.001), but lower for PTM position (P=0.04). Horizontally, tongue marker positions had moderate correlation with the jaw and hyoid during eating (r=0.47), due more to hyoid position than to jaw position. Overall, correlations were lower during speech than eating. This study demonstrated distinct kinematic linkages between the movements of the jaw, the hyoid and the anterior and posterior tongue markers, as well as differing impact of the jaw and the hyoid in determining tongue movement during eating and speech.

Articulation of fricatives: Evidence from X-ray microbeam data

Articulatory changes in /s/ over time give rise to the onset and offset of turbulence noise, but the small tolerances involved make it difficult to separately consider the effects of movement, phonetic context, and subject variation. Aerodynamic estimates of the constriction area have been shown to demonstrate a marked asymmetry, with the /s/ onset more rapid than offset [C. Scully, Speech Commun. 11, 1992]. Previous articulatory studies led us to expect an invariant tongue tip position, with jaw raising dependent somewhat on the following vowel. In order to investigate the timing of the constriction formation in fricatives, X-ray microbeam data [Westbury et al., 1994] for citation forms of /sVd/ for 15 vowels were studied. In fact, the tongue marker patterns during [s] vary both by following vowel and subject; subjects seem to have different apical-laminal strategies. The jaw reaches maximum height during [s] for each subject studied; that height does not appreciably vary with vowel. This indicates that jaw height is important specifically for /s/ production. One possibility is that the constriction is formed by the tongue, and turbulence noise is then maximized by the lower teeth being brought into position. [Work supported by NIH NIDCD R01 DC 006705.]

Tongue-jaw linkages in human feeding: A preliminary videofluorographic study

Motions of the tongue and jaw are closely coupled during feeding in mammals, but this relation has not been studied in humans. A videofluorographic method for measuring tongue movement relative to jaw motion using small radiopaque markers affixed to the tongue with dental adhesive was developed and tested in five individuals. Sagittal movements of the anterior tongue marker (ATM) and the lower jaw were measured for complete feeding sequences with a computerized image-analysis system. The ATM and jaw moved in loosely linked, semirhythmic cycles. Vertical and horizontal maxima of ATM motion were determined for each motion cycle in relation to maximum and minimum gape (greatest jaw opening and closeing, respectively). The amplitude of tongue movements and their timing differed between hard and soft foods (p < 0.001). For both food types, motions varied as the feeding sequence progressed from ingestion to terminal swallow (p < 0.001). A basic temporal sequence was found in 70% of the 224 cycles analysed. On average, the ATM reached its most inferior position just after maximum gape, its most posterior during jaw closing, its most superior just after minimum gape, and its most anterior during jaw opening (p < 0.001). This study confirms that tongue and jaw movements are linked during human feeding, as they are in other mammals.

Patterns of tongue and jaw movement in a cinefluorographic study of feeding in the macaque

Tongue movements in three female Macaca fascicularis, with radio-opaque markers in the tongue, teeth and hyoid, feeding on apple, banana and monkey chow, were recorded using lateral projection cineradiography (± 100 f.p.s.) with synchronized frontal view cinephotography (50 f.p.s.). Marker positions were digitized and the resultant Cartesian coordinates manipulated: (a) to establish the gape time profile; (b) anteroposterior and dorsoventral movements of tongue and hyoid markers relative to an upper occlusal/palatal reference plane; and (c) expansion and contraction of tongue segments in selected sections of complete sequences. The relative timing of tongue and jaw movement events was established using interval analysis. In simple transport cycles (semisolid food), all parts of the tongue moved in synchrony, travelling forwards and expanding during early opening, and backwards and contracting during late opening and closing. In contrast, in simple chewing cycles with a power stroke (SC phase): (a) the tongue markers reached their most backward position before or at the beginning of the SC phase, travelling forwards until the teeth approached intercuspation, then paused until after the teeth had reached centric occlusion; (b) the markers moved asynchronously, so that the relation between each marker and jaw movement changed; (c) expansion and contraction was largely confined to the middle tongue segment. In complex chewing cycles, jaw movement in opening was linked to the behaviour of the anterior tongue segment: reversal from forward to backward movement of the anterior tongue marker occurred within 30 ms of the rate change at the SO (slow open)-FO (fast open) transition: the greater the amplitude of forward movement, the longer the SO phase. Hyoid (tongue base) movement occurred throughout masticatory sequences. A backward drift of the hyoid and posterior part of the tongue occurred in cycles preceding swallows. Linkages between tongue and jaw movements in feeding in macaques are more complex than those reported for non-primate mammals, as they change between successive jaw cycles. The changes observed during sequences, and between different foods, suggest that the effector systems involved are continuously modulated, and the jaw-movement profile during opening may be dependent on the pattern of tongue movement.

Tongue movement of the cat during lapping

The movements of radio-opaque markers in the tongue were recorded cine-radiographically. The animals were fed bariumized milk, with or without a thickening agent to increase the viscosity. The movements of the tongue markers relative to the palate were roughly elliptical and resulted from the summation of at least three components: simple movement produced within the tongue, movement imposed on the tongue by hyoid movement and movement imposed on the tongue-hyoid complex by jaw movement. Relative to the palate, the anterior markers protracted high and retracted low, whereas the posterior markers did the reverse. The movements could be explained as having utility for the intra-oral transport of liquid by two mechanisms. The transported liquids then accumulated between the soft palate and the tongue prior to swallowing. The swallow appeared as a brief interruption in the jaw-opening phase of otherwise standard lapping cycles.