What are the approximate number of units of Botox required for jaw reduction?

To slim the face, Botox is injected into the masseter muscles. Appropriate patients for treatment have significant volume of muscle, rather than a strong bony prominence at the angle of the jaw (mandible). Injecting the masseter muscle with Botox decreases the prominence of the muscle and tapers the lower face. Dosage depends on the patient's muscle volume, together with regional and cultural variations in the amount of taper than is considered desirable and attractive.  In patients with small faces and modest muscle volume, tapering can be achieved with as little as 9-12 units per side. In patients with a large muscle volume the dosage required can be as high as 20-40 units per side. Most patients get noticeable tapering of the jaw with modest dosage. It is only patients with large muscles that require the higher dosage. The "equivalent" Dysport dosage would be anywhere from 30 to 100 units per side. Your lopsided chin can be managed by either dissolving the excess filler on the longer side or adding additional filler to the shorter side. I hope this helps. Best wishes to you. 

Botox can be injected into these areas to create a softer look and to help with TMJ. The botox will essentially relax the muscles creating the appearance of atrophic muscles. The results will last up to 3-4 months hence you will have to re-inject roughly 3x per year. When administered by an expert injector you shouldn't have an issue with too much laxity and should know the amount of units that should be used to get the results your desire.
If you're unhappy with your final results for the filler in your chin, you can have it reversed with hyaluronidase and try a different technique next time. I recommend seeing a facial sculpting expert.
 Best, Dr. Emer

Hi,Thank you for your question. The unit dosing for Botox and Dysport are different so it's not valid to make side by side comparisons. Generally, 20-25U of botox or 50-60U of dysport per side is a safe starting point (on the low side) for masseter injections. Depending on the extent of hypertrophy, up to 40U of botox and an equivalent amount of dysport can be used. Typically patients will require more than one treatment spaced 3-6 months apart. The masseter muscle does take some time to atrophy and show the effects of facial slimming.As for chin filler, there are 2 approaches that can be taken. If you prefer the more projected side, more filler can be injected to achieve better symmetry. If you or your injector feels there is too much volume, a dissolver can be used to reduce the volume/projection (if a hyaluronic acid (HA) filler was used).Hope this was helpful!