Table 1.
Absolute error (in mm) obtained with the different meshes for the considered four node positions in the apical, alveolar, velar and pharyngeal regions, as compared to the reference simulation with the most accurate mesh (the one with 3412064 nodes).
Fig 1.
3D FE model of the oral cavity.
Left: the FE model superimposed on the MRI data of RS in the mid-sagittal plane (Front is on the left). Right : Oblique anterior view of the model of the oral cavity with the tongue in rest position (magenta), the mandible (cyan), the hyoid bone (yellow), the maxilla (green), the hyoid muscles represented with lines (orange), and the thyro-hyoid membrane (light green).
Table 2.
Numbers of nodes and elements, and types of elements for each of the meshed anatomical structures implemented in the ANSYS MAPDL environment.
The types of contact between these structures are also listed.
Fig 2.
Vowel /i/ generated with the model using the Genioglossus partitioning shown in Fig 3.
Contours of the G-OBIM tongue model (in red) in the steady-state postures associated with the articulation of these sounds superimposed to various MR slices: (i) FE model of the tongue in the steady-state posture; (ii) sagittal views (left to right: mid-sagittal to left lateral); (iii) axial views (left to right: inferior to superior); (iv) coronal views (left to right: posterior to anterior); (v) enlargement of the tongue region in the mid-sagittal, (vi) axial and (vii) coronal views.
Fig 3.
Proposed functional partitioning of the Genioglossus resulting from the reproduction with the model of the articulation of vowel /i/ by RS.
GGa: yellow; GGm: green; GGp: red; GGh: cyan. Left: sagittal view; center: coronal; right: cavalier perspective view.
Fig 4.
Topological description of tongue muscles: Hyoglossus (HG).
Left: sagittal view; center: coronal or axial view; right: cavalier perspective view.
Fig 5.
Topological description of tongue muscles: Styloglossus (SG).
See Fig 4 for details.
Fig 6.
Topological description of tongue muscles: Inferior Longitudinalis (IL).
See Fig 4 for details.
Fig 7.
Topological description of tongue muscles: Superior Longitudinalis (SL).
See Fig 4 for details.
Fig 8.
Topological description of tongue muscles: Transversalis (Trans).
See Fig 4 for details.
Fig 9.
Topological description of tongue muscles: Verticalis (Vert).
See Fig 4 for details.
Fig 10.
Topological description of muscles acting on the tongue in the mouth floor: Geniohyoid (GH).
Left: sagittal view; center: coronal or axial view; right: cavalier perspective view.
Fig 11.
Topological description of muscles acting on the tongue in the mouth floor: Mylohyoid (MH).
See Fig 10 for details.
Table 3.
Mandibular opening (in mm) resulting from imposed displacements to match the mandible position in the MRI data.
Displacement of the hyoid bone (in mm) resulting from the activations of the Geniohyoid and Mylohyoid muscles and from imposed displacements in vertical directions. Displacement along X: front-back; displacement along Y: up-down.
Table 4.
Active stresses (in Pa) exerted by each muscle in the model to reproduce the articulation of /a/, /u/, /i/, /t/ and /k/ by RS.
Fig 12.
Contours of the G-OBIM tongue model (in red) in the steady-state postures associated with the articulation of these sounds superimposed to various MR slices: (i) FE model of the tongue in the steady-state posture; (ii) Sagittal views (left to right: mid-sagittal to left lateral); (iii) Axial views (left to right: inferior to superior); (iv) Coronal views (left to right: posterior to anterior); (v) Enlargement of the tongue region in the mid-sagittal plane, (vi) axial and (vii) coronal views.
Fig 13.
See Fig 12 for details.
Fig 14.
See Fig 12 for details.
Fig 15.
See Fig 12 for details.
Table 5.
Comparison of activated muscles for cardinal vowel generation using various biomechanical models from the literature. F: [12], B: [9], C: Our model.
Fig 16.
Localisation of the main improvements provided to the topology of the tetrahedral tongue mesh (around 3 million nodes), as compared to the last version of the tongue model [19] in our group.
Red frame: the sub-apical region is refined. Green frame: the external branches of the Styloglossus are repositioned to refine the position of their attachment on the Stylohyoid process on the skull. Yellow frame: the posterior triangular part of the Hyoglossus (Ceratoglossus) is enlarged to insert on the greater horn of the hyoid bone.
Table 6.
Mechanical parameters of the other anatomical of the oral cavity. From [11].