Botox is a drug prepared from the bacterial toxin botulin, used medically to treat certain muscular conditions and cosmetically to remove wrinkles by temporarily paralyzing facial muscles. (1) There are four preparations approved by FDA: OnabotulinumtoxinA , AbobotulinumtoxinA, IncobotulinumtoxinA, RimabotulinumtoxinB. (2)
Botulin toxin affects muscles by decreasing the intensity of muscle contractions, allowing the muscles to still function, but to relax them just enough to prevent intense contractions, which can cause the pain along with tooth damage. The masseter muscle may be a trigger point and can be the root cause of the jaw pain. By injecting BOTOX into a trigger point, it can reduce or eliminate the “referred pain” such as the distant jaw or facial pain. (3)
・Had an allergy to any of the ingredients in BOTOX or similar products
・Have a skin infection at the planned injection site
・Are being treated for urinary incontinence and have a urinary tract infection (UTI)
・Are being treated for urinary incontinence and find that you cannot empty your bladder on your own (only applies to people who are not routinely catheterizing) (8)
Botox injections can be given in several facial muscles, such as the masseter and temporalis. (4) The number of Botox injections for TMJ disorder will depend on the severity of your condition, but anywhere from 20 to 50 units may be injected on either side of the face.
When Botulinum toxin is injected into the temporalis and masseter muscles, it limits muscle function and might relieve pain associated with TMD.
Generally, a 12.7mm long needle is recommended based on the thickness of the soft tissues. The needle initially touches the bone. Withdrawing the needle by 3 mm after touching the bone is recommended, followed by injecting a portion of the Botox. Retracting the needle by 3 mm after the tip touches the mandible bone is one way to ensure that the needle successfully reaches the center of the masseter muscle. Do not exceed a total dose of 360 Units administered in a 3-month interval. (5)
(1) https://languages.oup.com/google-dictionary-en/
(2) AAN Updates Guidelines on the Uses of Botulinum Neurotoxin | AAFP
(4) https://www.rejuvdentist.com/biological-dentistry/botox-for-tmj/
(5) Kim, T., Merrill, R., Kim, H. (2018) Atlas of Botulinum Toxin Therapy for Masseter Muscle Hypertrophy, Sleep Bruxism and Headache. Yenang, Inc. Korea.
(7) https://www.westenddental.com/blog/uses-for-botoxh-in-dentistr