Will Botox Injections In The Treatment of Masseteric Muscle Dehiscence Cause The Muscle To Drop Down Back In Place?

Q: Dr. Eppley, I currently have large posterior PEEK jaw angle implants (~12mm width; no vertical augmentation). My presentation is complicated by significant bilateral masseter dehiscence, as I have history of prior jaw surgeries. The appearance is the classic skeletonized angles + the muscle bulge superiorly. 

I have read your various posts on masseter muscle reattachment via external approach both on your blog and on forums. I discussed this with my prior surgeon. However, he/she does not think it’s a good idea to do an external surgical reattachment of the muscle to the inferior border of the implants out of fear this may cause masseter tearing, as, given my history of surgeries, there is likely fibrosis within the muscles. In addition, my implants are large. 

Instead, the surgeon has recommended 3-4 Botox regimens over the course of a couple years, which he/she said would help the muscle “fall back down” over the inferior border. He/she said repeated treatments would eventually cause some degree of permanent atrophy and could help eliminate the appearance of the superior bulge. 

I don’t like the idea of using Botox. In addition, I prefer more permanent solutions. 

My questions are: 

1) Is the risk of masseter tearing a reasonable concern when considering masseter reattachment for the treatment of dehiscence. 

2) Would you ever recommend Botox as an effective non-surgical treatment for masseter dehiscence, or is this truthfully just a fairly ineffective alternative. 

A: In answer to your masseteric muscle dehiscence issues:

1) Botox injections are a reasonable treatment option with the understanding of the following:

   a) Their effects are usually temporary and have to be repeated.

   b)  Even with repeated injections any sustained permanent muscle reduction effect may or may not occur. (I have never seen it happen yet) 

   c) The appearance of the muscle bulge will definitely become less but the muscle will not fall back down. This is biologically impossible as it is a contracted muscle mass now. It will not unfortunately just ‘relax’ and go back into place. This is known as magical thinking.

   d) At best Botox will produce a lessening of the muscle dehiscence appearance but it will not make it go away completely.

2) The risk of masseter muscle repositioning is not whether the muscle will tear but whether it is so fibrotic that it simply won’t move much. (unsuccessful repositioning) The other thing you have to consider is how to fix it the muscle to the PEEK material if you are fortunate enough that it is capable of being mobilized.

3) Any effort at masseteric muscle repositioning must be preceded by Botox injections to get the muscle to relax/soften a bit. One or two rounds of Botox, preferably two, before such surgery improves the chances of success.

Dr. Barry Eppley

Indianapolis, Indiana