Injectable fillers come in several types depending on the area to be filled. For the cheeks, a thicker, hardier filler is generally used. Examples include Restylane Lyft, Voluma, or Radiesse. In my mind, these are pretty much interchangeable and last about the same amount of time. It just depends on doctor preference. There is a newer filler called Renuva which works by stimulating fat cells in your own tissue to grow. I have been seeing some very nice results with this one in the cheek area. I don't think regular Restylane works as well in the cheek area. As for needles versus cannulas, I tend to use needles when injecting into the cheeks except for Renuva. That one requires a cannula for insertion.