They are possible when the filler is 'fresh'. After a while the result can kind of look a little shop worn as the 'sharpness' it kicks up initially kind of blunts over time. For what he got to the jaws, the filler would have to be high viscosity (thick).
Lazlo,
SJ used 'Macrolane' which is a really THICK filler because it's meant for the BODY. The doc who did it (Big Belly) was in the bag with SJ (condoned his non disclosure of owning the biz he hid he owned via endorsing it) and wrote a paper about using Macrolane (a body filler) with SJ as the 'model' for it. Tim06 in another thread, mentioned that it's been discontinued 'banned?' for use in Europe.
I would make damned sure and double check that the patient in that photo is 'JUST' filler and that it is not a bait and switch for implants as the guy does do jaw implants.