Botulinum toxin is produced by an anaerobic bacteria (Clostridium Botulinum) in 7 strains; A, B, C, D, E, F, G. Botulism; a lethal food poisoning that may affect humans, animals, birds, is caused by strains: A, B, E. Those used in therapy are type A (since 30 years) and type B (since 20 years). It acts by blocking the release of acetyl choline mainly at the motor end plate (myoneural junction) i.e. chemical dennervation. In therapy it acts within few days, to reach a reasonable effect after 2 weeks. It lasts for 4-6 months after which reinjection is mandatory due to reccurance of syptoms due to the phenomenon of sprouting then re-establishment of the original myoneural junction. Oromandibular dystonia (OMD) is either opening mouth, closing mouth or combined. In the first type the following muscles are injected lateral pterygoid, ant. belly of digastric and myelohyoid, while in the second type the following muscles are injected temporalis, masseter and medial pterygoid. In the combined type both groups are injected. Video presentations will be illustrated.