3 weeks post op, how long until masseter Botox starts to show?

Thank you for your question. Botox in the masseter region usually takes longer than in the standard areas to take effect. I tend to use anywhere from 15 units (conservative treatment) to 50 units (for someone with really strong masseters) on each side to get the desired result. It may start within the first week but I tell my patients to wait three weeks before doing a more thorough evaluation. The treatment typically lasts longer than the forehead/crows feet/frown regions. It is also a gradual onset of the return of masseter function. I have tried the masseter injections myself and space the treatments around 4 months apart, but use smaller doses to maintain the effect. I normally know the effects are wearing down when I start to clench my teeth more heavily at night when asleep. Once you stop using Botox, the masseter muscles will return to their original baseline when the effects of Botox wears off completely.It is hard to know why you are not seeing results that you are expecting without being to evaluate before/after pictures and know the injection technique and dosing used by your injector.  You may want to revisit your injector or also seek a second opinion from a more experienced injector.

Considering you have had 2 injections, wait 4 weeks until you evaluate your results. It doesn't hurt to visit your injector and have your questions answered. Botox takes time to show results. Initially you may need more Botox depending how strong your muscle is. 

The masseter is one of 4 muscles involved in chewing, and it is a very large, bulky muscle.  Botox will effectively relax this muscle in about a week, however it does take time for the muscle to atrophy and shrink.  Over the course of the first month, after an effective treatment, you should notice a gradual tapering of the lower third of your face.  Especially for first-timers, an additional treatment may be necessary 2-4 weeks after the first treatment to fully relax the muscle.  

I do this type of treatment everyday.  It typically takes 7-10 days to start to notice a change in the masseter and shouldn't require a second treatment unless a very small amount was done the first time.  Each injection session takes roughly 2 weeks to see the ultimate results.  You should have a decreased pain in the TMJ after treatments.  Do you know what dosages were performed?  I suggest getting a second opinion.  Best, Dr. Emer.

The masseter is a large, strong muscle so it will take longer to see results after Botox treatment than other areas of the face. It can take up to 4 weeks for you to start seeing the results. Also, depending on the size of your muscle it may take a few treatments to reach the appropriate dosage for you that will give the best results. Make sure you continue your follow-up with your injector.

first the muscle weakens usually within a week or so, but it takes a month or so for the actual bulk of the muscle to shrink...so time is required...you probably show allow at least a month between injections into this area which is different than treatment for the typical cosmetic issues...of course it only works if the issue is enlargement of the masseter muscle...tough to say what's causing the tmj pain...several possibilities...there may be some asymmetry in muscle function which is placing uneven stress on one side...or it may be an issue with placement of the injections...or it may have to do with irritation from the shots...good luck with your results

Injection into the masseters with Botox can slim the face IF the masseters are enlarged.  If the problem is fat related, it won't help much.  Also, the amount of units must be at least 20 each side and can be up to 40 each side.  Results might not be noticed until a second treatment is performed.  Soreness in TMJ can be related to one muscle being weaker than the other and causing a shift in the jaw.

Your soreness may be from a bruise (small hematoma/bleeding) or swelling.  All of which usually resolves within a week.  I find it takes 1-3 months to start seeing the change in shape of your lower face after the masseter treatment, so I would give it a little more time.  It may take longer in someone who continues to use their masseter more than others, with activities such as chewing gum.  Try clenching your teeth and feeling the masseter muscle by the angle of the mandible, and compare to your friend or family member who has not had the treatment.  Yours should feel smaller.  If you have excess fat over the masseter, then you won't see as significant an improvement, and may benefit from another treatment like lipodissolve.