By the doctor Lakhdar Belhaouari

A veritable fourth-dimension symbol, myomodulation is defined as the regulation of the activity and movement of a muscle, to either stimulate or relax it. Known for being a filler product, hyaluronic acid can also be used for muscular modulation. We have been aware of this for many years in our aesthetics practice.



Myomodulation that stimulates the muscles

It is only in the middle third of the face that we have noticed this, when injecting hyaluronic acid into the deep malar fat. This has a double effect: it enhances the fullness of the facial volumes while lifting the middle third of the face. This lifting effect is explained by the myotatic reflex of extension, which we described in 2014 (ref. 1 and 5) and by the relationship between active tension and the length of a muscle, which was outlined by the Frankel and Nordin parabola (ref. 2).

Myomodulation that relaxes the muscles

This has been observed in many areas of the face when hyaluronic acid is injected into or directly in contact with the muscle. The HA gel penetrates and infiltrates the muscle fibres and therefore eases their function: this myomodulation relaxes the muscles.

It can be found in the:

Chin, when volumising hyaluronic acid is injected into the chin for retrogenia, which relaxes the mentalis muscle.
Latero-orbital area when reshaping the upper external part of the cheekbones. The HA soaks into the fibres of the lateral part of the orbicularis oculi muscle. As this muscle relaxes, the tail of the eyebrow is lifted, as the muscle’s function is to pull it down.
Forehead, when beautifying a flat forehead. The HA soaks into the frontalis muscle and has a relaxing effect, though milder than botulinum toxin.
Jawline, when injecting into the edge of the jaw for a better-defined facial contour. The HA is injected into where the masseter muscle runs into the bone: by relaxing it, we can relax a tense face. The same thing happens when we fill the temples, as the temporal muscle acts in the same way as the masseter.
Lips, when injections are made into the orbicularis oris muscle. The HA soaks into its fibres to relax taut lips. The smile looks more beautiful and the lips are enhanced by their shapely contours, eversion, projection and hydrated and glossy appearance, and the relaxing power of myomodulation.


In all of these muscles, the hyaluronic gel finds its way into or between the muscle fibres and reduces their tension, reduces their trajectory and relaxes the contractile function of the muscle fibres without blocking them, by altering their viscoelastic properties in a way that eases them.

Their active tension is reduced, relaxed, without altering the muscle’s function, which is changed by making its movements gentler.

Due to the agonistic-antagonistic muscle balance mechanism, we also know that other muscles can be affected by the myomodulation of the muscle concerned (ref. 4-5).

All of this is described in the book “The art of injections in aes- thetics”, published in January 2021, written with Claire Beylot, Véronique Gassia, Thierry Michaud and Pierre Quinodoz (ref.5).


Références :

1. Belhaouari L. J. Méd. Esth. et Chir. Derm. Vol. XXXXI, 164, décembre 2014, 203-209.
2. Margareta Nordin, Victor Hirsch Frankel. Basic Biomechanics of the Musculoskeletal System, Wolters Kluwer/Lippincott Williams & Wilkins Health, 2012
3. Belhaouari L, Quinodoz P, Lauwers F. J.Med.Esth. Chir. Derm. Vol 46 , 183, sept 2019, 219-225
4. Belhaouari, Tomassety M, Quinodoz P, De Boulle K. Myomodulation & Hyaluronic acid Prime January 2020 57-61
5. Belhaouari L, Beylot C, Gassia V, Michaud T, Quinodoz P, L’art des injections en Esthétique, éditions Arnette France 2021


By the Doctor Lakhdar Belhaouari
Nationally and internationally recognised aesthetic and medical surgeon.
As co-author of a report on lifts and of three books including “The art of injections in aesthetics” (released in 2021) as well as numerous publications, Doctor Lakhdar Belhaouari shares his technical and anatomical expertise in rejuvenation and beautification.

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