title: Botulinum A exotoxin for glabellar folds: a double-blind, placebo-controlled study with an electromyographic injection technique.
abstract: BACKGROUND
  Botulinum A exotoxin (BTX) has been used successfully to treat a variety of hyperkinetic movement disorders. BTX is also capable of reducing hyperkinetic facial lines including prominent glabellar frown lines.
  
  
  OBJECTIVE
  The purposes of this study were to (1) confirm the efficacy of BTX in a double-blind, placebo-controlled investigation; (2) evaluate the use of an electromyogram attached to the injection needle to confirm intramuscular corrugator placement of the BTX; and (3) determine the optimum direction injection technique.
  
  
  METHODS
  Length and depth of glabellar frown lines were measured before treatment and 4 and 12 weeks after injection of 10 units of BTX or saline solution.
  
  
  RESULTS
  Patients treated with BTX had a highly significant reduction in depth and length of glabellar frown lines compared with control subjects.
  
  
  CONCLUSIONS
  BTX appears to be effective and safe for reduction of glabellar frown lines.
authors.affiliation: Skin Research Foundation of California, Santa Monica, USA.
authors.forename: N J
authors.initials: NJ
authors.lastname: Lowe
authors.forename: A
authors.initials: A
authors.lastname: Maxwell
authors.forename: H
authors.initials: H
authors.lastname: Harper
mesh_terms: D019274:Botulinum Toxins, Type A / Q000008:administration & dosage / Q000627:therapeutic use*; D004311:Double-Blind Method; D004576:Electromyography / Q000295:instrumentation; D005098:Exotoxins / Q000008:administration & dosage / Q000627:therapeutic use*; D005152:Facial Muscles / Q000503:physiopathology; D005546:Forehead; D006801:Humans; D006948:Hyperkinesis / Q000628:therapy; D007273:Injections, Intramuscular / Q000295:instrumentation; D009069:Movement Disorders / Q000628:therapy; D009119:Muscle Contraction; D009339:Needles; D009465:Neuromuscular Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D010919:Placebos
chemical_list: D005098:Exotoxins; D009465:Neuromuscular Agents; D010919:Placebos; D019274:Botulinum Toxins, Type A