I have been performing nonsurgical chin augmentations for well over twenty years. Since cannulas were first approved for use in Israel well before their approval in the U.S., I had the opportunity of using them in my Israel satellite facilty long before I was able to use them in my Upper East Side NY office. Frankly, I prefer needles to cannulas, since needles travel through skin more smoothly and require less pressure, and in general placement of the filler is more precise with them, and, as a result of that less filler is typically needed to accomplish the job. Although cannula manufacturers claim that cannulas are safer, less painful, and cause less bruising, the reality is that microcannulas can and do puncture blood vessels and therefore can cause bruising. Furthermore, since a similar fanning method of injection, which employs just one entry point can be used with needles, as well as with cannulas, andsince the entry point can be numbed with a local containing epinephrine (a blood vessel constrictor), the injection process with a needle can actually prove less painful than with a cannula. And regarding discomfort, it should be noted that cannula treatments require an initial piercing with a needle--yes, that's right, the first site must be first punctured with a needle anyway--and because there has to be the pushing action with cannulas in order to slide its blunt tip through tissues, it can also be quite uncomfortable for some patients. Finally, cannulas are considerably more expensive than needles, which can add to the cost of the treatment. So, all in all, after having had experience with both needles and cannulas for quite a few years, with few exceptions, I prefer the needle to the cannula for its overall benefits to the patient. Hope this helps.