title: Systematic review of clinical trials of small- and large-gel-particle hyaluronic acid injectable fillers for aesthetic soft tissue augmentation.
abstract: BACKGROUND
  Hyaluronic acid (HA) is the most frequently injected filler for soft tissue augmentation in the United States.
  
  
  OBJECTIVE
  To systematically review published evidence for aesthetic use of small- and large-gel-particle HA.
  
  
  METHODS
  Clinical data on anatomic area, level of evidence, patient population, trial design, endpoints, efficacy, and safety were extracted from PubMed.
  
  
  RESULTS
  Fifty-three primary clinical reports were analyzed. The highest-quality efficacy evidence was for the nasolabial folds (NLFs), with 10 randomized, blind, split-face, comparative trials. Several randomized, blind trials supported treatment of the glabella, lips, and hands. Lower-level evidence (from studies with nonrandomized, open-label, or retrospective designs) was recorded for the nasojugal folds (tear troughs), upper eyelids, nose, infraorbital hollows, oral commissures, marionette lines, perioral rhytides, temples, and cheeks. Common adverse events (AEs) across anatomic areas were pain, bruising, swelling, and redness. Serious AEs were uncommon (8 events in 8 patients of 4,605 total patients) and were considered to be unrelated (7 events) or probably unrelated (1 event) to treatment.
  
  
  CONCLUSIONS
  The efficacy and safety of small- and large-gel-particle HA are well established for NLFs; evidence for the glabella, lips, and hands is more limited. Preliminary reports in other anatomic regions suggest efficacy without major complications.
authors.affiliation: AboutSkin Dermatology and DermSurgery, Englewood, Colorado 80113, USA. jcohenderm@yahoo.com
authors.forename: Joel L
authors.initials: JL
authors.lastname: Cohen
authors.forename: Steven H
authors.initials: SH
authors.lastname: Dayan
authors.forename: Fredric S
authors.initials: FS
authors.lastname: Brandt
authors.forename: Diane B
authors.initials: DB
authors.lastname: Nelson
authors.forename: Robert A
authors.initials: RA
authors.lastname: Axford-Gatley
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Theisen
authors.forename: Rhoda S
authors.initials: RS
authors.lastname: Narins
mesh_terms: D002986:Clinical Trials as Topic; D003357:Cosmetic Techniques; D005782:Gels; D006801:Humans; D006820:Hyaluronic Acid / Q000008:administration & dosage* / Q000737:chemistry; D010316:Particle Size; D015595:Skin Aging / Q000187:drug effects*; D016896:Treatment Outcome; D055675:Viscosupplements / Q000008:administration & dosage* / Q000737:chemistry
chemical_list: D005782:Gels; D055675:Viscosupplements; D006820:Hyaluronic Acid