AbstractBotulinum toxin was first used therapeutically by a German physician Justinus Kerner (1786-1862). Trade name BOTOX was given by Allergan, Inc, Irvine, Calif for treating strabismus, blepharospasm, and hemifacial spasm. It is neurotoxin derived from an anaerobic bacteria Clostridium botulinum. The toxin inhibits the release of acetylcholine (ACH), a neurotransmitter responsible for the activation of muscle contraction and its administration results in diminution of tone in the injected muscle. It has found a variety of uses in dentistry like treatment of gummy smile, masseteric hypertrophy, bruxism, temporomandibular disorders and so on. It is a minimally invasive and cosmetically effective method of treating several conditions with excessive muscle contraction.