Pearls and Pitfalls in Botox Injections for TMD

OnabotulinumtoxinA (Botox®) corresponds to a neurotoxin protein secreted by the bacterium Clostridium Botulinum. Its mechanism corresponds to blocking the release of acetylcholine from presynaptic motor nerve endings, resulting in the relaxation of muscles and the relief of neurogenic pain. It has an analgesic effect at the central level, although it is still controversial in the literature. Botox® affects the nociceptive mechanism by preventing the release of inflammatory mediators such as glutamate and substance P. Ultimately, its analgesicOnabotulinumtoxinA (Botox®)analgesic effect action also includes an effect on the postganglionic sympathetic ending, inhibiting the release of norepinephrine and ATP, two stimulating neurotransmitters of muscle nociceptors. The application of botulinum toxin in its subtypes A and BOnabotulinumtoxinA (Botox®)subtypes A and B is widely used in the management of the muscular component of temporomandibular disorders as a second line of treatment or as a coadjuvant strategy to reduce joint loading from masticatory muscles and to reduce intramuscular pain associated with parafunctional habits (e.g., clenching, teeth grinding). Botox® therapy is often combined with traditional medical/conservative management such as orthotic therapy, NSAIDS, muscle relaxants, diet restrictions, patient education, physical therapy, etc. A relevant element to consider when using Botox® is the correct indication. To do this, we must consider some diagnoses and conditions to be ruled out, which can confuse the clinician at the time of patient evaluation and lead to the use of this therapy incorrectly and with uncertain results. Among these, we have: