Is the Botox Needle for Jawline Bigger?

The needle used to treat the masseter is indeed longer than the needle used to treat the forehead as the masseter is a very thick muscle, and a longer needle is necessary to effectively reach the body of the muscle.  This is in contrast to the other facial muscles which are located more superficially.  I use a 1.0" long needle (30g) when injecting Botox for masseter reduction.I use a 0.5" long needle (32g) when injecting the other facial rhytids.  The gauge (or thickness) of the needle (30g vs. 32g) is the important factor regarding discomfort, and both 30g and 32g are extremely skinny.  Discomfort is very minimal with these small needles.  I like comparing them to mosquito bites. More important than needle size is the surgeon administering your Botox as results are very technique dependent.  

The needle used for injection of the jawline is identical to the needle used for the injection of the forehead. There are many different injection techniques and practitioners may vary.

The same sized needle is used for injecting Botox in any area.  It is a very fine needle that most patients find very comfortable.

We generally use a small size 30 gauge needle for injecting Botox anywhere on the face or neck.
The techniques are slightly different among different injectors but the results are generally the same.