Hyaluronic acid injection technique for the lips 

- Category: Esthetic medicine injections

Hyaluronic acid is an absorbable filler. Its relatively short duration (6 to 12 months) requires new injections to maintain the result. It is essential to check the origin of the syringes before starting the injection. Doctors obtain them in 2 ways, either by buying the Hyaluronic Acid directly from the laboratory, or by buying the Hyaluronic Acid in a pharmacy (or on specialized sites selling Hyaluronic Acid linked to pharmacies) which obtain it directly from the laboratory. Hyaluronic acid is a glycosaminoglycan that will hydrate and restore volume to the dermis.

On the beauty market, it can be found in a non-cross-linked and cross-linked form. The CE label guarantees the safety of the product in terms of manufacture and material.

Cross-linking consists of increasing the links between the hyaluronic acid chains. It increases the lifespan of the molecule by delaying its degradation by hyaluronidases and increases its viscosity.

A gentle injection and the use of cannulas will be essential to reduce the risk of hematomas. Some Fillers contain Lidocaine. The purpose of this addition is not to reduce the pain during the injection, but rather to improve post-injection comfort.

This is an act that must be performed with all safety measures for the patient, even if the rich vascularity of the face reduces the risk of infection.

Facial make-up removal and local disinfection with a colorless antiseptic are essential steps.

Hand washing and the use of sterile equipment (gloves, mask, surgical drapes, compresses, needles and cannulas) are the equipment that the practitioner must provide to carry out the treatment.

Local anesthesia is performed on the areas to be treated by applying a thick layer of Emla type cream to the skin 30 to 60 minutes beforehand. In the case of very sensitive patients, it is possible to anaesthetize the entry point of the cannula by an intra-dermal injection of 0.1 ml of 2% Xylocaine, using a fine hypodermic needle. The penetration of the needle to make the pre-hole will then be imperceptible.

The injection is carried out using a needle or cannula with the smallest diameter that allows the hyaluronic acid gel to pass through. Depending on its viscosity, the number of gauges of the needle must be evaluated. 

The cannula has a variable length depending on its diameter, and its end has a blunt tip that gently pushes the vascular, nervous and muscular elements. It must be of the same calibre (or greater) as the cannula.

The advantages of its use are:

• A limitation of the number of puncture points
• Reduced pain 
• A reduction in the risk of haematomas and bruises
• For the doctor: the possibility of pre-dissecting the injection and the possibility of treating several areas from a single-entry point

The needle injection is performed repeatedly, as a backtracking or bolus injection. The injection depth is intradermal or subdermal.

Objectives:

• Redefine the contours
• Increase their volume
• Treat « barcode » wrinkles

The linear retro-trace technique is used for implantation in the majority of lip injections.

One syringe is sufficient for the initial treatment of both lips, with a touch-up performed two to four weeks later.

Redefining the contours: The edge of the upper lip is created by an injection along the edge of the vermilion. The injection is very superficial. It can be performed with a cannula, by retro-tracking, the pre-hole being placed at the lateral part, or with a needle, requiring several injection points. Superficial subcutaneous injection

Increasing the volume of the lips:  The injection is often done with a cannula in the body of the orbicularis, by retro-tracing. When an increase in the lip volume is desired, the contours are redefined and then the injection into the mucosa itself is performed. Deep subcutaneous injection. 

Generally equivalent amounts of hyaluronic acid are normally used for lip edge enhancement and volume increase (for example half a syringe each).

Barcode wrinkles: The treatment of vertical wrinkles of the upper and lower skin lips is a frequent request on mature skin, the hyaluronic acid must absolutely be slightly cross-linked, which means thin, not very thick. Intra-epidermal injection. Each wrinkle is treated one by one, with a needle, intra-dermally and retro-tracing.

Anatomy of the lips (source Aesthetics Journal)

1-Philtrum

2- Philtrum ridges 

3- Vermilion border 

4- Cupid’s bow

5- Left upper lip

6- Oral commissure 

7- Tubercle

8- Body of the lip 

9- Cutaneous upper lip