# The role of lingual frenulum on tongue mobility: a biomechanical modeling study

Maëlle Courtin, Yohan Payan, Pascal Perrier, Morgane Evin, Emilie Clady, Pierre Frémondière, Mohammad Ali Nazari, Maxime Calka

► To cite this version:

Maëlle Courtin, Yohan Payan, Pascal Perrier, Morgane Evin, Emilie Clady, et al.. The role of lingual frenulum on tongue mobility: a biomechanical modeling study. Multidisciplinary Biomechanics Journal, 2025, 50th congress of the.., 10.46298/mbj.16257. hal-05191818v2

HAL Id: hal-05191818

https://hal.science/hal-05191818v2

Submitted on 23 Oct 2025

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
# The role of lingual frenulum on tongue mobility: a biomechanical modeling study

Maëlle Courtin<sup>a</sup>, Yohan Payan<sup>a</sup>, Pascal Perrier<sup>b</sup>,
Morgane Evin<sup>c</sup>, Emilie Clady<sup>d</sup>, Pierre Frémondière<sup>d, e</sup>,
Mohammad Ali Nazari<sup>f</sup>, Maxime Calka<sup>b*</sup>

<sup>a</sup> Univ. Grenoble-Alpes, CNRS, Grenoble INP, TIMC, F-38000 Grenoble, France

<sup>b</sup> Univ. Grenoble-Alpes, CNRS, Grenoble INP, GIPSA-Lab, F-38000 Grenoble, France

<sup>c</sup> Univ. Aix-Marseille, iLab Spine, F-13000, Marseille, France

<sup>d</sup> École universitaire de Maïeutique Marseille, France

<sup>e</sup> ADES UMR 7268 Aix Marseille Univ, Marseille, France

<sup>f</sup> School of Mechanical Engineering, University of Tehran, Tehran, Iran

* Corresponding author: maxime.calka@univ-grenoble-alpes.fr

Received date: 04/04/2025

Accepted date: 27/06/2025

Publication date: 27/10/2025

**Keywords:** biomechanical FE models, baby
tongue, frenulum, frenectomy, ankyloglossia

© 2025 The Authors

Licence CC-BY 4.0

Published by Société de Biomécanique

# 1. Introduction

Ankyloglossia, or tongue-tie, is a condition that limits tongue mobility and affects around 3% of infants, often making breastfeeding difficult. The lingual frenulum is seen as a key factor in this disorder. Since the early 2000s, the number of frenotomies—surgical cuts of the frenulum—has increased significantly, despite ongoing debates about their effectiveness and the lack of long-term data (Sawai et al., 2024).

To better understand the impact of the lingual frenu-
lum on tongue mobility during breastfeeding and evalu-
ate treatment options, the TongueTieNum project aims
to develop a biomechanical finite element (FE) model of
a newborn's tongue. This model simulates the tongue's
mechanical interactions with the mother's nipple to esti-
mate the tongue's pressure on the nipple depending on
the frenulum's morphology and mechanical properties.
The objective of this preliminary study is to quantify
the influence of the frenulum on the pressure that the
tongue can exert on the nipple.

## 2. Methods

### 2.1 Generation of the FE newborn tongue model

The FE newborn tongue model was generated starting
from a model that represents the tongue of a French
male called “Reference Subject” (bmi of 20 kg/m²,
aged 60), using a 3D non-rigid landmark-based volume
image registration method (Bijar et al., 2016) between
MRI 3D views of the heads of the Reference Subject

(RS) and of a newborn. The optimal transformation
between the 2 MR image sets was applied to the RS FE
tongue model (Calka et al., 2025) in order to transform
its morphology into the one of the newborn tongue.

## 2.2 Nipple modelling

As a first step, a rough model of the nipple was gener-
ated (Figure 1 – panel d), which consists of a deform-
able cylinder of 24 mm in diameter and 35 mm long
(Alatalo et al., 2019). In a first approximation the nipple
was assumed to have the same material properties as
the tongue. Standard mechanical contacts were defined
between the tongue, from the tip to the blade, and the
lowest part of the cylinder that represents the nipple.

## 2.3 Studying tongue mobility: a sensitivity study

Simulations were carried out to determine the impact
of the frenulum's morphological and mechanical char-
acteristics on tongue mobility for a gesture that simu-
lates tongue movement during breastfeeding. In these
simulations, the front part of tongue was raised by the
activation of the superior longitudinalis (SL) muscle.
This elevation induced an increase of tongue pressure
on the nipple. A sensitivity study was carried out on
3 characteristics of the frenulum (F): morphology, thick-
ness and stiffness. Three morphologies were considered
according to the proximity of the frenulum's insertion
relative to the tongue tip (Figure 1 – panel c): posterior
(P), median (M), anterior (A). Two thicknesses (T) were
tested: 1 mm and 3 mm. Stiffness (S) was defined based the value proposed by Souiki et al., 2025 (this conference), considering ratio of 1 or 3 with regard to the rigidity of the tongue (Yeoh 2 parameters, C1=192Pa, C2=90Pa). Thus, 12 simulations were carried out that were referenced as F-(P, M, A) T-(1, 3) S-(1, 3).

# 3. Results and discussion

## 3.1 FE newborn model

The FE newborn model is shown in Figure 1. The registration process enabled us to obtain an accurate morphology that fits well to the MRI ground truth.

## 3.2 Sensitivity study of the tongue frenulum

The simulations show that the most important property is the position of the frenulum used. For each position, Table 1 lists the mean and the standard deviation of the tongue pressure exerted on the cylinder representing the nipple, together with the maximum pressure (4 simulations for each position with various T and S).

<table><caption>**Table 1.** Mean and standard deviation of the pressures exerted by the tongue against the cylinder that represents the nipple for each frenulum position tested.</caption><thead><tr><th></th><th>Mean (Pa)</th><th>SD (Pa)</th><th>Max (Pa)</th></tr></thead><tbody><tr><td>F-P</td><td>123.7</td><td>1.7</td><td>224</td></tr><tr><td>F-M</td><td>87.5</td><td>4.9</td><td>186</td></tr><tr><td>F-A</td><td>75.5</td><td>11.7</td><td>178</td></tr></tbody></table>

These preliminary results show that an anterior frenulum is more restrictive than a posterior one, supporting the idea that ankyloglossia results from an overly forward frenulum that limits tongue mobility, especially its elevation toward the palate in newborns. In addition, low standard deviation shows that thickness and stiffness parameters have little influence for posterior tongue frenulum, but much more for the anterior ones, with a maximum pressure of 178 Pa for the F-A T-3 S-3 simulation.

# 4. Conclusions

To conclude, this work presents the design of a FE newborn tongue model including an account of the tongue frenulum with the aim of carrying out a sensitivity study to characterize which parameters play major roles in the emergence of an ankyloglossia.

<figure><img src="image_2.png" /><figcaption>**Figure 1.** FE newborn model. Panel (a): FE newborn with anterior tongue frenulum (in violet). Panel (b): FE model superimposed on newborn MRI in the sagittal plane of the head. Panel (c): SL muscle. Panel (d): FE model with nipple model.</figcaption></figure>

This work is preliminary and does not yet allow us to draw definitive conclusions about the role of the frenulum and its morphology in breastfeeding. However, it does offer a new approach based on biomechanical modeling that can further be used in research on breastfeeding and its impairments.

As a short-term perspective, the realism of the model will be improved by adding the mandible while sucking movements will be simulated using tongue muscle coactivation.

In the long term, this model could be coupled with the breast model developed within the TIMC laboratory (Mîra et al., 2018).

# Conflict of Interest Statement

None.

# Contributor Roles

Maëlle Courtin: Modeling, Methodology, Writing; Yohan Payan: Methodology, Writing, Supervision, Funding; Pascal Perrier: Methodology, Writing, Supervision; Morgane Evin: Methodology, Writing, Supervision, Project initiator; Emily Clady: Consulting, Writing; Pierre Frémondière: Consulting, Writing;
Mohammad Ali Nazari: Modeling, Writing; Maxime
Calka: Methodology, Writing, Supervision;

References

Alatalo, D., Jiang, L., Geddes, D., & Hassanipour, F. (2019). Nipple deformation and peripheral pressure on the arealo during breastfeeding. *Journal of Biomechanical Engineering, 142*(1), 011004. https://doi.org/10.1115/1.4043665

Bijar, A., Rohan, P. Y., Perrier, P., & Payan Y. (2016). Atlas-based automatic generation of subject-specific finite element tongue meshes. *Annals of Biomedical Engineering, 44*, 16–34. https://doi.org/10.1007/s10439-015-1497-y

Calka, M., Badin, P., Nazari, M. A., Rochette, M., Perrier, P. et al. (2025). The G-OBIM tongue model: An accurate open-source biomechanical model of a male human tongue. *PLOS Computational Biology* 21(9), e1013378. https://doi.org/10.1371/journal.pcbi.1013378

Mîra, A., Carton, A. K., Muller, S., & Payan, Y. (2018). A biomechanical breast model evaluated with respect to MRI data collected in three different positions. *Clinical Biomechanics, 60*, 191–199. https://doi.org/10.1016/j.clinbiomech.2018.10.020

Sawai, A. C., Mahajani, M., Subhadarsanee, C., Patil, K., Dhadse, P. V., Sawai Jr, A. C., & Patil, K. S. (2024). Management of tongue-tie using conventional technique for speech clarity and correcting malocclusion: A case report. *Cureus, 16*(7). https://doi.org/10.7759/cureus.63756