This article has been medically reviewed for accuracy by Laguna Niguel, CA dermatologic surgeon Dr. Lorrie Klein on March 4, 2024.
Botox is perhaps most renowned for its wrinkle-smoothing impact on the forehead and crow’s-feet, yet the injectable neurotoxin has numerous other uses. One of the initial applications of botulinum toxin was to treat blepharospasm; nowadays, it’s also a common therapy for those dealing with migraines, cerebral palsy spasms, and excessive perspiration. And an increasingly popular injection site blurs the boundary between medicine and aesthetics, providing benefits to both fields. Masseter Botox (also known as Botox injections in the jaw) can be employed to address TMJ or slenderize the jawline—and many individuals rely on it for both purposes.
Ahead, doctors offer insights into how masseter Botox functions, who makes a suitable candidate, and whether you should be concerned about the peculiar side effects you might have come across on social media.
How does masseter Botox work?
The same principles of muscle relaxation applicable to any type of Botox injections hold true here. “Botox hinders muscle contractions, which also leads the muscle to shrink over time,” explains Dr. Jessie Cheung, a board-certified dermatologist in Willowbrook, Illinois. Consider it like losing muscle tone after a period of inactivity – if that muscle is weakened, it will also decrease in size, adds Dr. Konstantin Vasyukevich, a New York City board-certified facial plastic surgeon. That initial aspect – a relaxed and weakened masseter, the muscle extending from the temple to the lower jaw – helps alleviate common symptoms of TMJ, reducing jaw tension and pain and minimizing grinding and clenching, states Dr. Y. Claire Chang, a board-certified dermatologist in New York City. The shrinkage contributes to a slimmer lower face and a less square jawline.
It’s worth noting that at times, Botox needs to be injected not only into the masseter but also the temporalis muscle. These are two of the four “chewing” muscles, and both are accountable for bruxism, the technical term for grinding or clenching, as mentioned by Dr. Cheung. “Clenchers tend to have enlarged temporalis muscles. Grinders tend to have enlarged masseters and hollowed temples because the chronic tension accelerates fat loss in this area,” she elaborates. Either way, injecting into either or both regions contributes to a more slender appearance of the face.
How much Botox is used in the masseter?
The concise answer: a considerable amount. It varies depending on the patient and the size of their muscles, but Dr. Chang indicates that she typically uses 50 to 60 units in total. Similarly, Dr. Cheung says that on average, she injects 30 units per side. Dr. Vasyukevich mentions that he typically commences with 25 units per side but often increases it to 50 units per side.
How long does masseter Botox last?
While Botox generally has an approximate lifespan of three to four months, the higher dose utilized in the masseters implies that the injections in this area can persist for up to six months, as per Dr. Cheung.
Who is a good masseter Botox candidate?
“Those with severe TMJ symptoms or teeth grinding could be candidates, particularly if lifestyle modifications and night guards have proved ineffective,” says Dr. Chang. It helps address the root cause of bruxism, adds Dr. Cheung; while a mouth guard protects your teeth, it doesn’t halt the grinding and clenching. If that’s not an issue for you and your motivation is purely aesthetic, it’s a favorable option for those with a broader or square jawline who desire it to have a more V-shaped contour.
Who isn’t a good candidate?
Alongside the typical Botox considerations – it’s not suitable for anyone who is pregnant, breastfeeding, or has neuromuscular disorders – those with significant skin laxity should proceed with caution, notes Dr. Chang. “Reducing the volume around the angles of the jaw can loosen the skin of the lower face and potentially result in a less distinct jawline,” adds Dr. Vasyukevich. He also points out that sometimes fullness on the side of the face can be a consequence of overdeveloped parotid (salivary) glands – in such cases, reducing the size of the masseter won’t aid in achieving a slimmer appearance.
Can masseter Botox have negative side effects?
Search for masseter Botox on TikTok, and you’ll discover numerous videos extolling the results… and plenty cautioning about strange side effects, including worsened jaw clenching, an asymmetrical smile, and an inability to chew. So what’s the deal? According to Dr. Chang, bruising, mild soreness, and tightness are typically common due to the needle injections, but they usually subside within one to two weeks. Similarly, “fatigue or difficulty chewing hard or tough foods is also common for the initial few weeks because the masseter muscle has been weakened. Over time, other jaw muscles compensate and chewing returns to normal,” she says. If you feel that your clenching has worsened after the injections, it might be that only your masseter was injected and you also require injections in the temporalis muscle, notes Dr. Cheung.
All things considered, “proper masseter Botox should not impact your smile. If it’s injected too far forward or too superficially, it will affect the risorius muscle, which is responsible for lifting the smile,” explains Dr. Cheung. The outcome: a droopy or uneven grin. Unfortunately, the sole remedy here is time. The Botox will eventually wear off, and in the meantime, exercising your smile muscles (in other words, smiling as much as feasible), can facilitate its faster dissipation, she says.
What not to do after masseter Botox
Adhering to a few straightforward precautions following masseter Botox injections can guarantee you obtain the most favorable results and help minimize the potential for any undesirable side effects. Firstly, wait at least 12 hours before engaging in any strenuous cardio exercise, such as cycling or intense running; the increased blood flow could, theoretically, shift the neurotoxin to unintended areas before it can fully bind to the targeted muscle. You should also keep your head upright – no napping or performing downward dog poses – for at least four hours after your appointment. And finally, wait approximately 12 hours before applying any pressure on or around your jaw muscles, whether through a facial massage or using a tool like a jade roller. Once again, this type of pressure can cause unwanted diffusion or spread of the Botox.
