Physician preference and experience typically dictate the choice of cannula or Needles. Needles allow for more precise placement of the filler, although there may be a somewhat higher chance for bruising following treatment. Accordingly, they are preferable in areas where placement within the skin is critical, such as under the eyes or if filling a very fine, etched line or wrinkle. Cannula advocates claim that the cannula is safer to use and less likely to give rise to bruising. The truth is that when smaller gauge cannulas are used, they can puncture and pierce blood vessels much like needles. And large gauge cannulas do allow for precise placement, nor can they be used in thin-skin regions. I have used both and generally prefer the needle for most areas. More important than cannula vs. needle is that you seek consultation and treatment by an experienced, board certified aesthetic physician: dermatologist, plastic surgeon, facial plastic surgeon, or ENT plastic surgeon, and make sure to ask to see his/her personal before and after photos before agreeing to proceed. Best of luck.