The human tongue is a structurally complex and extremely flexible organ. In order to better understand the mechanical basis for lingual deformations, we modeled a primitive movement of the tongue, sagittal tongue bending. We hypothesized that sagittal bending is a synergistic deformation derived from co-contraction of the longitudinalis and transversus muscles. Our model of tongue bending was based on classical bimetal strip theory, in which curvature is produced when one muscle layer contracts more so than another. Contraction was modulated via mismatched thermal expansion coefficients and temperature change (to simulate muscular contraction). Our results demonstrated that synergistic contraction produced curvature and strain results which were in better correspondence to empirical results derived from tagging MRI than were the results of contraction of the longitudinalis muscle alone. This fundamental reliance of tongue bending on the synergistic contraction of its intrinsic fibers supports the muscular hydrostat theory of tongue function.

1.
Miyawaki, K., 1974, “A Study of the Musculature of the Human Tongue,” Annual Bulletin of the Research Institute of Logopedics and Phoniatrics, University of Tokyo, 8, pp. 23–50.
2.
Smith
,
K. K.
, and
Kier
,
W. M.
,
1989
, “
Trunks, Tongues, and Tentacles: Moving with Skeletons of Muscle
,”
Ann. Sci.
,
77
, pp.
29
35
.
3.
Napadow
,
V. J.
,
Chen
,
C.
,
Wedeen
,
V. J.
, and
Gilbert
,
R. J.
,
1999
, “
Intramural Mechanics of the Human Tongue in Association with Physiological Deformations
,”
J. Biomech.
,
32
, pp.
1
12
.
4.
Matthys
,
L.
, and
DeMey
,
G.
,
1996
, “
An Analysis of an Engineering Model for the Thermal Mismatch Stresses at the Interface of a Uniformly Heated Two Layer Structure
,”
Int. J. Microcircuits Electron. Packag.
,
19
, pp.
323
329
.
5.
Suhir
,
E.
,
1989
, “
Interfacial Stresses in Bimetal Thermostats
,”
J. Appl. Mech.
,
56
, pp.
595
600
.
6.
Timoshenko
,
S.
,
1925
, “
Analysis of Bimetal Thermostats
,”
J. Opt. Soc. Am.
,
11
, pp.
233
255
.
7.
Chiel
,
H. J.
,
Carago
,
P.
,
Mansour
,
J.
,
Hathi
,
K.
,
1992
, “
Biomechanics of a Muscular Hydrostat: A Model of Lapping by a Reptilian Tongue
,”
Biol. Cybern.
,
67
, pp.
403
415
.
8.
Wilhelms-Tricarico
,
R.
,
1995
, “
Physiological Modeling of Speech Production: Methods for Modeling Soft Tissue Articulators
,”
J. Acoust. Soc. Am.
,
97
, pp.
3085
3098
.
9.
Hashimoto
,
K.
, and
Suga
,
S.
,
1986
, “
Estimation of the Muscular Tensions of the Human Tongue by using a Three-dimensional Model of the Tongue
,”
J. Acoust. Soc. Jpn. (E)
,
7
, pp.
39
46
.
10.
Sanguineti
,
V.
,
Laboissiere
,
R.
, and
Payan
,
V.
,
1997
, “
A Control Model of Human Tongue Movements in Speech
,”
Biol. Cybern.
,
77
, pp.
11
22
.
11.
Mu
,
L.
, and
Sanders
,
I.
,
1999
, “
Neuromuscular Organization of the Canine Tongue
,”
Anat. Rec.
,
256
, pp.
412
424
.
12.
Shanley, F., 1957, Strength of Materials, McGraw-Hill Book Company, Inc., New York.
13.
Visible Human Project Web Site-http://www.nlm.nih.gov/research/visible.
14.
Duck, F. A., 1990, Physical Properties of Tissue: A Comprehensive Reference Book. Academic Press, London.
15.
Matsumoto
,
Y.
,
1967
, “
Validity of the Force-Velocity Relation for the Muscle Contraction in the Length Region, l<lo,
J. Gen. Physiol.
,
50
, pp.
1125
1137
.
16.
Elliott
,
G. F.
,
Lowy
,
J.
,
Worthington
,
C. R.
,
1963
, “
An X-Ray and Light-diffraction Study of the Filament Lattice of Striated Muscle in the Living State and in Rigor
,”
J. Mol. Biol.
,
6
, pp.
295
305
.
17.
Abbott
,
B.
, and
Baskin
,
R.
,
1962
, “
Volume Changes in Frog Muscle during Contraction
,”
J. Physiol. (London)
,
161
, pp.
379
391
.
18.
Napadow
,
V. J.
,
Chen
,
Q.
,
Wedeen
,
V. J.
,
Gilbert
,
R. J.
,
1999
, “
Biomechanical Basis for Lingual Muscular Deformation During Swallowing
,”
Am. J. Physiol.
,
277
, pp.
695
701
.
19.
Niitsu
,
M.
,
Kumada
,
M.
,
Campeau
,
N. G.
,
Niimi
,
S.
,
Riederer
,
S. J.
, and
Itai
,
Y.
,
1994
, “
Tongue Displacement: Visualization with Rapid Tagged Magnetization-Prepared MR Imaging
,”
Radiology
,
191
, pp.
578
580
.
20.
Axel
,
L.
, and
Dougherty
,
L.
,
1989
, “
MR Imaging of Motion with Spatial Modulation of Magnetization
,”
Radiology
,
171
, pp.
841
845
.
21.
Young
,
A. A.
, and
Axel
,
L.
,
1992
, “
Three-dimensional Motion and Deformation of the Heart wall: Estimation and Spatial Modulation of Magnetization—A Model-based Approach
,”
Radiology
,
185
, pp.
241
247
.
22.
Zerhouni
,
E. A.
,
Parish
,
D. M.
,
Rogers
,
W. J.
,
Yang
,
A.
, and
Shapiro
,
E. P.
,
1988
, “
Human Heart: Tagging with MR Imaging—A Method for Noninvasive Assessment of Myocardial Motion
,”
Radiology
,
169
, pp.
59
63
.
23.
Crandall, S., 1959, An Introduction to the Mechanics of Solids, McGraw-Hill Publications, New York.
24.
Kakita
,
Y.
, and
Fujimura
,
O.
,
1977
, “
Computational Model of the Tongue: A Revised Version
,”
J. Acoust. Soc. Am.
,
62
, pp.
S15
S15
(A).
25.
Kiritani
,
S.
,
Miyawaki
,
K.
,
Fujimura
,
O.
, and
Miller
,
J. E.
,
1976
, “
A Computational Model of the Tongue
,”
Annual Bulletin, Research Institute of Logopedics and Phoniatrics, University of Tokyo
,
10
, pp.
243
251
.
26.
Weijnen
,
F. G.
,
Kuks
,
J. B.
,
van der Bilt
,
A.
,
van der Glas
,
H. W.
,
Wassenberg
,
M. W.
, and
Bosman
,
F.
,
2000
, “
Tongue Force in Patients with Myasthenia Gravis
,”
Acta Neurol. Scand.
,
102
, pp.
303
308
.
27.
Robbins
,
J.
,
Logemann
,
J.
, and
Kirshner
,
H.
,
1986
, “
Swallowing and Speech Production in Parkinson’s Disease
,”
Ann. Neurol.
,
19
, pp.
283
287
.
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