How many units of Botox will I need for jaw reduction? It's my first ever Botox so I want to go slowly (Photo)

Botox is a great option for shaping and contouring the face.  Injection of the masseter muscles should help relieve grinding of the teeth at night but may or may not have effects on tension that extends down to you shoulder.  As is always the case, there is a range of dosages that may be required.  Starting conservatively and working your way up may be helpful.  Too large a dose can lead to a sunken-in look. 

Generally, we use 20-40 units of Botox for each side of the masseter depending on the size and strength of the muscle.