Unfortunately, insurance companies do not usually cover this treatment. Patient in some cases though will use a health savings account to pay for the treatment.
Botox in the masseter muscle for teeth grinding is considered off-label but effective. I typically use 15 -20 u per side but some patients require more. Results can last quite a while- longer than the average cosmetic duration of action. Unfortunately, since the treatment is off-label, insurance companies typically do not cover the cost. Best of luck!