I’ve had Botox before, and needles don’t faze me—especially when I’m lying in a cushy treatment chair with Lady Gaga in the background. That said, even if you’re not needle-friendly ...

Masseter Botox is a procedure in which botulinum toxin (or another neurotoxin) is injected into the masseter muscle, one of the main muscles in the jaw used for chewing.

That's what happens to the muscles on the corner of the jaw [after the injection]; essentially, you're not moving them as much, as they're not clenching." Are there any side effects to masseter Botox?