Why inject Botox into the masseter muscle?
The masseter muscle is the one that cups your jawline and helps you chew and eat. When it gets too strong, it can widen your face. What pumps up the masseter muscle? Grinding, clenching, and other “TMJ” issues. If you need to wear a nightguard for your teeth, wake up with soreness in your jaw or headaches, or have cracked teeth, you are likely having this issue. The fancy term for this is “bruxism.”
Is there a negative effect? Journal time!
We do Botox injections into the masseter muscle all the time. I LOVE IT. Not only can it slim the jawline, it truly helps with the nighttime grinding. But with all treatments, is there a negative? This was in the Aesthetic Surgery Journal January 2026 issue. “Longitudinal CT Indicates NO Negative Impact of Botox on Mandibular Bone Density in a 12 Month, Double Blind, Randomized, Repeat Treatment, Placebo controlled Study in Health Adults with Masseter Muscle Prominence.” (Whew! What a title. You don’t even need to read the study.)
This study was done to evaluate if doing Botox into the muscles of mastication changes the biomechanical loading- would this lead to bone density changes?
Study:
- 123 patients
- 12 month, double blind, placebo controls, dose escalation
- Patients got 1 or 2 bilateral treatments or placebo. CT scans were done at baseline, Day 90, and Day 360 after treatment
- Cortical and trabecular bone densities were calculated for the condyles, premolar dentalveolus, and ramus
- Findings? No clinically significant changes in bone density were seen.
Dr. Greenberg thoughts on Botox for TMJ
I love Botox for TMJ issues. It works well. I can see those who grind from across the room due to the bulk of their masseter. Many people are a little freaked out that I can tell they are clenchers/grinders/TMJ people- its just that I can see the muscle beefy-ness.
Instead of headaches and worn down or cracked teeth, treat it with Botox. I’m a huge fan. Great to know it isn’t causing an unintended issue with bone density. This study was done well- double blinded, randomized, etc. as there have been other studies which hint Botox may cause bony issues.
Medical Citation
The information provided on this website is for general informational purposes only and does not constitute medical advice, diagnosis, or treatment. Always seek the advice of a qualified healthcare provider for any questions regarding your health or medical condition.
