AIME Paris 2022 SYMPOSIUM "VIVACY
How to harmonize the contours of the face and sublimate the lips in all elegance?
Dr. Sophie Converset-Viethel, MD
Dr. Chloé Faure, MD
Pr Barbara Hersant, MD
Injections of filling products, particularly hyaluronic acid, in the face and more particularly in the lips are currently very fashionable and are increasingly publicized through social networks. Thus, we are witnessing requests from younger and younger patients.
Due to the democratization of hyaluronic acid injections, the procedure is often "trivialized" and taken lightly by patients. Nevertheless, it is important to remember that it remains a medical procedure that is not without risk and for which there are a certain number of rules to follow for good practice.
There are many injection techniques, especially for the lips, with more or less natural results, but the most important thing to remember is obviously to respect the patient's request.
The purpose of these communications is to recall the basic principles in order to optimize results and avoid complications.
2. ANATOMY AND PHYSIOLOGY OF AGING
A/ ANATOMICAL REMINDERS
The face is composed of several tissue layers, from the surface to the depth (fig.1)
- The cutaneous layer, the skin.
- Superficial fat, present everywhere on the face, from the forehead to the neck. It should be noted that within this layer there are differences between the laterofacial area and the perioral area. Indeed, the perioral area is much more subject to muscular forces and thus disappears more quickly with age.
- The ligaments of the face, which can be broken or weakened with the cannula. 
- The muscular layer with the muscles of the mimicry, which also contains the vascularization.
In particular, the facial artery is foundwhich originates from the neck and then travels along a path that passes under the platysma, under the depressor angulis oris, then under the large zygomatic muscle.
It then bifurcates at the level of the insertion of the zygomaticus major, i.e. at the level of the labial commissure, into the facial artery and the superior coronary artery, also called the superior labial artery.
The superior labial artery has in most cases the same caliber as the facial artery, therefore relatively important.
Its course is sub-mucosal, retro-muscular, behind the orbicularis muscle of the lips.
Note that there is no anatomical variation concerning the labial artery, contrary to the facial artery which can vary at the level of the nasolabial fold..
- The deep submuscular fat, for example in the orbital area with the "SOOF" (SubOrbicularis Oculi Fat) located behind the orbicularis muscle and the "Orbital Fat Pad" in the lower eyelid area (Fig. 2)
- The periosteum.
B / PHYSIOLOGY OF FACIAL AGING
The concept of triangles helps to illustrate aging. Beauty is embodied by the inverted triangle, i.e. with a superior base, thus with volume distributed on the upper and middle thirds and less volume on the lower part.
With time and aging, the triangle is reversed with the distribution of volumes drawing a triangle with a lower base.
All the layers mentioned above are subject to physiological aging, which is a multifactorial phenomenon.
The skin loses elasticity, the subcutaneous fat atrophies and fatty ptosis occurs.
Muscles also atrophy with age but are also responsible for a change in the distribution of fat. For example, at the orbicular level, by contracting, the muscles exert mechanical forces on the fatty tissues which are both pushed upwards, leading to the appearance of bags on the lower eyelids, but also pushed downwards with the appearance of what is called the valley of tears.
Finally, one should not underestimate bone aging. With age, there is bone resorption, particularly in the temporal bone, which is responsible for hollow temples.
Posture, physical therapy, orthognathic surgery or orthodontics play an important role in the development of the teeth.and in some cases allow to slow down this bone ageing process.
Thus with aging we observe:
- Wrinkles related to muscle aging and skin retraction
- Sliding corridors, secondary to fat ptosis related to gravity and fat atrophy with the appearance of hollows, particularly in the midface and periorbital areas.
- An impression of excess skin and fat related to bone resorption.
To rejuvenate a face, one should not hesitate to fill in the upper part of the face and rather play on the repositioning of the tissues in the lower part in order to find the inverted triangle. Deep injections, in contact with the bone, can be performed at an early age, around 35/40 years, to support the superficial tissues.
It should be noted that the cartilage, especially in the nose, also ages enormously and we observe a production of cartilage with age responsible for a drooping tip and the appearance of a bump on the dorsum.
The same is true for surgical rhinoplasties which also age.
C/ THE TRAP ZONES
There are some "danger zones" on the face that should be avoided.
The first is represented by the superficial temporal artery, which is located in the temporal fossa. A lesion of this artery does not normally lead to any vascular risk or necrosis, just a hematoma or bruise.
More importantly, the facial artery should also be avoided in depth, it can be drawn to avoid it along an oblique path from the commissure to the mandibular basilar edge (Fig. 3).
At the level of the chin strap: no danger for the nerves which are located laterally and higher.
3. GENERAL RECOMMENDATIONS HARMONIZE THE CONTOURS OF THE FACE AND ENHANCE THE LIPS WITH ELEGANCE
First of all, it is important to respect the recommendations established by the laboratories marketing the product.
Indeed, the clinical studies carried out on the products are carried out with the syringe and the needle provided in the boxes. The properties of hyaluronic acid are thus obtained for use with a certain type of equipment.
Any modification of the material could lead to a change in the rheological properties (= mechanical behavior) of the hyaluronic acid in question.
The respect of the packaging proposed by the laboratories thus guarantees an optimal effectiveness of the product.
Needle or cannula?
It is advisable to perform the injections with a cannula whenever possible, which has many advantages.
Firstly, medicine is based on the principle of "primum non nocere", the use of the cannula thus makes it possible to respect this principle by avoiding the vascular risks
In addition, the use of a cannula allows for control of the path and position of the cannula tip, which also avoids path changes and thus makes the injection less risky.
Injection with a cannula is probably faster than with a needle, and avoids clumps of product and rapid shaping.
It is important to remember that you can get the same results with the cannula as with the needle while gaining in safety.
However, there are some disadvantages, for example, resistance may be greater with the cannula in certain areas.
The patient must also be warned that there will be some edema after the procedure, more significant with the cannula than with a needle, with resorption in 15 to 21 days.
Concerning the choice of the cannula, the larger the diameter and the more rigid the cannula, the less risk one takes, a very fine cannula behaves almost like a needle, so a size of 25G seems a good compromise.
However, there are places where the cannula cannot be used, especially in the periosteum. In this case, a direct route to the bone contact is used to be safe.
What about anesthesia?
A local anesthesia can be performed, it makes the procedure more comfortable for patients but is not mandatory because it is often a source of bruising.
If it is performed, it is advisable to avoid performing local blocks because lidocaine cannot be injected perfectly identically on both sides, which may result in small asymmetries in the mimicry and it is then impossible to know whether the asymmetry is related to the injection or to the anesthesia.
For anesthesia, prefer an injection under the mucous membrane, which can nevertheless cause bruising, or an application of EMLA® cream before the procedure.
4. FOCUS ON THE LIPS
- Lip injections are currently in great demand and the current fashion is for fuller lips, but it should not be forgotten that the natural lip respects a ratio of 1/1.6.
- The projection of the labial artery (upper and lower) is located at the junction of the dry lip and wet lip of the red lip (upper and lower)
- Upper red lip:
The injection is done as seen before with a 25 gauge cannula, the only thing done with the needle is the pre-hole at the level of the red lip, often responsible for ecchymosis.
Care must be taken to be submucosal, as the orbicularis muscle of the lips is extremely thin and the artery which is retro-muscular is thus very close to the injection site.
The submucosal plane is found at the dry lip/wet lip junction of the red lip.
- Lower red lip
For the lower red lip, the injection is more risky because the lip is often a bit splayed, so we are located on the junction dry lip-wet lip of the red lip.
As in the upper region, it is important to remain submucosal to avoid the inferior labial artery.
- Upper white lip
As we age, we often see numerous fine lines on the upper white lip, also known as the "bar code".
The bar code is linked to the disappearance of superficial fatty tissue leading to the appearance of fibrous tractiles between the skin and the muscle. The fact of passing the cannula already allows to break these tractiles and a reduction of the wrinkles, but it is not enough because they risk to reform.
The application of the acid in topping thus avoids the reformation of these fibrous tractiles. To correct this, the injection must be extremely superficial in the superficial fatty tissue. In general, an injection of 0.2 ml is sufficient.
If there is atrophy of the white lip, in this case we place the fat flap under the mucous membrane, in the plane of the vessels to restore volume.
The treatment of the white lip should not be neglected. If the white lip is not treated, the results are not as good.
There is one indication at the level of the lips for which the use of a cannula is not optimal, and that is to raise the lateral commissure.
However, there are no vessels in this area.
Indeed, the bifurcation of the superior and inferior coronary arteries occurs 8 mm from the lateral commissure, so needle injection is less risky.
The needle can also be useful for injection of the philtral ridges.
5. HOW TO GET A BEAUTIFIED FACE  
If we observe a baby, its temples are bulging and form a convex link between the forehead and the zygoma. With time and bone resorption the temple becomes hollow.
The filling in of the temples will go unnoticed but will unconsciously bring about a feeling of youthfulness in the eyes of the other person.
To fill the time :
The injection is done with a very reticulated product in the temporal fossa at the level of the most hollow zone by avoiding the superficial veins.
It must be deep, in the muscle, and must therefore be performed with a needle. The needle is inserted up to the guard and care must be taken to inject the product relatively slowly, otherwise it may cause headaches.
There is also a subcutaneous technique, therefore superficial, but this technique is more time consuming, the product is more difficult to model and risks to migrate according to the positioning, in particular if the patient sleeps on the side
The topping technique results in more irregularity and more risk of bruising and hematoma.
However, be careful with the lower part of the temple, the product may migrate towards the temporomandibular joint and the cheek. This is related to the temporal muscle, the main muscle of mastication, which has a strong attachment to the temporal bone and then runs in a groove above the zygomatic arch and then over the coronoid process.
For a natural result on the cheekbones it is important not to be excessive, in general half a bulb per side is more than enough.
The injection is done with a cannula following an external oblique vector in the deep subcutaneous and retro tracing. This gives a lifting effect on the mid face.
This is a topping technique. For a natural result, it is advisable to avoid boluses which are very conspicuous, especially when smiling.
The mandibular angle and the jow line
Democratized by Angelina Joli, the fact of having a marked mandibular edge and thus a very structured face is now a common request.
Injections at the mandibular angle and at the jowl line are interesting to embellish a face if the bone seems a little erased but be careful, it is very masculinizing and should be avoided for patients who already have a square jaw. It all depends on the patient's wishes, it is necessary to adapt to the request.
Concerning the angle, the injection is done in three points, one point opposite the angle itself, one point 1 cm above and one point 1 cm below at the mandibular line on the horizontal branch.
For the jow line we place ourselves a little behind the facial artery, in contact with the mandible along the basilar border and we can inject a few boluses as needed.
It is not necessary to learn points by heart, the main thing is to feel the reliefs and especially to adapt to the patient.
Chin: very reticulated product, long-lasting, in contact with the bone, chin projection
The injection technique is different depending on whether you want to feminize or masculinize a chin.
To feminize: the injection is performed through a low point located at the chin tuft. The injection is made with a highly reticulated product, with a needle perpendicular to the bone. This increases the projection of the chin and requires little product.
To masculinize, the male chin being more square, this time we carry out 2 injection points on both sides of the tuft, with the needle until the bone contact we inject a bolus on each side.
Hyaluronic acid injections facials are experiencing a sharp increase in demand at the moment.
It is imperative to avoid complications as much as possible by choosing to perform injections with a cannula.
There are many injection techniques for each area with relatively similar results.
The techniques described here ensure a good aesthetic result while maintaining optimal safety, but there are many others.
Finally, when it comes to the choice of techniques and results, it is important not to forget to listen to the patient and to adapt to his or her needs.
 Anatomical basis for rejuvenation surgery, R Sinna, E Delay, Annals of aesthetic plastic surgery. Oct 2017, vol 62: 355-364.
 Les injections usuelles en médecine esthétique, JP Meningaud, B Hersant, 2020-2021.
 Les injections non usuelles en médecine esthétique, JP Meningaud, B Hersant, 2020-2021.