Different facial regions and the severity of volume deficit affect the injection technique and volume of implant injected.
Insert the needle at an angle of 30° into the deep dermis. The bevel should be oriented downwards to minimize implant deposition into a more superficial plane. Palpate the region with your free hand to confirm insertion of the needle into the skin layer of interest. Superficial injection or deposition of large volumes of the implant may result in discoloration, nodules, or ischemia at the skin surface.
Inject the gel by applying mild continuous pressure on the plunger rod while slowly withdrawing the needle, thus forming a single uniform thread of injected gel inside the tissue (linear threading technique). While correcting deep folds, several threads should be layered in parallel lines beneath the fold. If larger volumes are required, such layers can be deposited on top of each other, the threads of each layer perpendicular to those in the underlying layer (cross hatching technique).
Substantial mechanical resistance to the injection of the implant may be resolved using the following measures: first, horizontally relocate the needle; second, inject from a different entry point; third, replace the needle or even the syringe.
Blanching may indicate injection into a superficial skin layer or a blood vessel. In case of blanching, stop injecting and massage the area until the color returns to normal.
If normal skin color does not return, the injection process should not resume. Vasodilatory or other measures should be considered.
Stop injection before pulling the needle out of the skin to avoid gel leakage into superficial skin layers.
Discard the needle in the appropriate biohazard waste bin.
Repeat the procedure if further correction is necessary, but only after thoroughly assessing the treated area and patient status.
After completing the injection, gently massage the treated area to ensure even distribution of the gel and to mold the gel to the tissue contour.