Botox on masseter muscle and wider mouth. Any suggestions?

Botox in select patients, can decrease the size of one or both masseter muscles to make the jaw appear smaller. Changing the amount of mouth opening is a more complex issue based on the reason your jaw opening is limited. There are 4 major muscles that affect jaw position by opening (lateral pterygoid)  and closing it (masseter, temporalis, and medial pterygoid). In addition there are minor muscle groups that contribute. The temporomandibular joint  or TMJ may have arthritis-like issues that affect jaw opening. It could be any of the muscles or the joint or both. Some oral surgeons specialize their whole career on just this area. I would consider this a more advanced use of Botox due to the complex anatomy. Please seek out someone who performs this particularly technique a lot for the safest results. 

Dear Julianhk:if if a tight, chronically contracted masseter is the cause for your small mouth opening, relaxing it should help.All the best,Dr. Clark