title: Long-term treatment of glabellar rhytides using onabotulinumtoxina.
abstract: OBJECTIVE
  To determine whether injection every 4 months with onabotulinumtoxinA provides longer-lasting reduction or elimination of glabellar rhytides.
  
  
  METHODS
  Toxin-naive women (N=45) aged 30 to 50 with moderate to severe glabellar lines at maximum contraction completed the study. Five sites were treated with 4 U of onabotulinumtoxinA. Participants were assessed at day 30; those with glabellar severity of none to mild remained in the study. Participants received identical treatments at months 4, 8, 12, 16, and 20, and were assessed without treatment at 24, 25, and 26 months.
  
  
  RESULTS
  Baseline physician- and participant-rated treatment responders at maximum contraction were 84% and 80%, respectively, at month 20; and 56% and 58%, respectively, at month 26. Mean changes from physician- and participant-assessed Facial Wrinkle Scale at maximum contraction from baseline to all postbaseline measurements were significant (p≤.001). The percentage of participants reporting neutral (0) to couldn't be more satisfied (+4) with their appearance ranged from 91% to 100% during months 1 to 24. At month 26, 87% of participants reported satisfaction, with appearance scores between 0 and +4. No adverse events were reported.
  
  
  CONCLUSIONS
  OnabotulinumtoxinA delivered for 20 months significantly reduces or progressively eliminates glabellar rhytides for up to 6 months after the last treatment.
authors.affiliation: Department of Oculofacial Plastic Surgery, Oregon Health & Sciences University, Portland, Oregon 97239, USA. daileyr@ohsu.edu
authors.forename: Roger A
authors.initials: RA
authors.lastname: Dailey
authors.forename: Asha
authors.initials: A
authors.lastname: Philip
authors.forename: Greg
authors.initials: G
authors.lastname: Tardie
mesh_terms: D000328:Adult; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage* / Q000627:therapeutic use; D005260:Female; D005546:Forehead; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D017060:Patient Satisfaction; D015595:Skin Aging / Q000187:drug effects*; D018709:Statistics, Nonparametric; D016896:Treatment Outcome
chemical_list: D019274:Botulinum Toxins, Type A