Injection technique in neurotoxins and fillers: Indications, products, and outcomes

Injectable fillers and neuromodulators are used for a range of indications pertaining to the correction of facial aging and disfigurement. Fillers can correct soft tissue loss, depressed scars, and atrophy or asymmetry induced by systemic or local disease. Neuromodulators correct muscle-mediated skin creases, reshape the face, and address right–left functional asymmetry. Among the prepackaged injectable fillers approved by the US Food and Drug administration are hyaluronic acid derivatives, calcium hydroxylapatite, and poly-L-lactic acid; neuromodulators include three types of botulinum toxin type A and one type of type B. Adverse events associated with injections are typically mild, easily managed injection pain, followed by redness, swelling, and bruising. Asymmetry, nodules, ptosis, and intravascular occlusion are less common. Filler and toxin injections are part of a complete treatment plan. Reinjection is typically required to maintain the clinical effect, and combination treatment with laser and energy devices can enhance the aggregate effect.