Research progress on the application of botulinum toxin type A in the treatment of myogenous temporomandibular disorders

Myogenous temporomandibular disorder (M-TMD) is one of the main subtypes of temporomandibular disorder (TMD) and typically manifests as masticatory myofascial pain; the incidence of TMD has been increasing annually in recent years. Botulinum toxin type A (BTX-A) is a potent neurotoxin produced by Clostridium botulinum. BTX-A inhibits the release of acetylcholine from the presynaptic membrane, thereby blocking neuromuscular junction signaling. The noncosmetic application of BTX-A in the oral and maxillofacial regions is a prominent research topic. In recent years, an increasing number of studies have focused on the application of BTX-A in the treatment of M-TMD. The results of a literature review revealed that an appropriate dose (10-50 U unilaterally) of BTX-A administered in a single injection into the masticatory muscles can effectively treat myalgia over a period of 3-6 months. Common adverse effects, such as masticatory weakness and facial paralysis, are transient and can be avoided by standardized inject