Sinus infections can be a source of potential infection during dermal filler treatments, so it is best to postpone the procedure until you are feeling well. According to the FDA, accidental injections of facial fillers into blood vessels can occur anywhere on the face, but are more likely to happen between the eyebrows and nose, around the nose, on the forehead, and around the eyes. Experienced injectors who have a deep understanding of facial features usually don't inject much into laughter lines. The cause of laughter lines is the drooping of the cheeks. To counteract this, we now know that filling the cheeks and sides of the cheeks (zygoma) is the best way to naturally reduce creases.
Otherwise, injecting into the folds can create an unnatural fullness that doesn't look good.