title: A double-blind, clinical evaluation of facial augmentation treatments: a comparison of PRI 1, PRI 2, Zyplast and Perlane.
abstract: BACKGROUND
  Facial wrinkles are caused by weakening of the sub-dermal collagen support layer. Dermal fillers can be used to treat wrinkles, and this double-blind, randomised, single-centre study compared four fillers: PRI 1, PRI 2 (both porcine collagen), Zyplast (purified bovine collagen) and Perlane (cross-linked hyaluronic acid gel).
  
  
  METHODS
  79 females (aged 25-55 years) with wrinkles in the upper lip line border were randomised to PRI 1 (19 patients), PRI 2 (19 patients), Perlane (23 patients), Zyplast (18 patients). Patients were assessed at 1 week and 1, 3, 6, 9 and 12 months using 2D images and by mathematically derived facial volume changes using 3D stereophotogrammetry.
  
  
  RESULTS
  All treatments produced larger, less wrinkled, more prominent lips. PRI 1, PRI 2 and Zyplast showed similar lip volume gains, with Perlane showing the greatest upper lip volume increase. All treatments were comparable for rates of decrease in upper lip volume post-treatment, however, Perlane maintained higher lip volume gains at each time point. Investigators indicated PRI 1 was significantly easier to deliver than Zyplast. Patient satisfaction scores were similar, though there was a trend towards greater dissatisfaction for PRI 1 and PRI 2 at month 9 (p=0.052). Treatment was well-tolerated, with 'cold sore' being the most common adverse event.
  
  
  CONCLUSIONS
  Results showed that PRI 1 and PRI 2 were comparable to Perlane and Zyplast as dermal fillers. Further rigorous studies are required to establish the performance of dermal fillers and patient acceptability. We propose the utilisation of stereophotogrammetry for assessment of volume changes.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Southern General Hospital, 1345 Govan Road, Glasgow G51 4TF, UK.
authors.forename: Jeff
authors.initials: J
authors.lastname: Downie
authors.forename: Zhili
authors.initials: Z
authors.lastname: Mao
authors.forename: Tsz-Wai
authors.initials: TW
authors.lastname: Rachel Lo
authors.forename: Sarah
authors.initials: S
authors.lastname: Barry
authors.forename: Mitchum
authors.initials: M
authors.lastname: Bock
authors.forename: J Paul
authors.initials: JP
authors.lastname: Siebert
authors.forename: Adrian
authors.initials: A
authors.lastname: Bowman
authors.forename: Ashraf
authors.initials: A
authors.lastname: Ayoub
mesh_terms: D000328:Adult; D001672:Biocompatible Materials / Q000627:therapeutic use; D003094:Collagen / Q000627:therapeutic use; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006820:Hyaluronic Acid / Q000627:therapeutic use; D021621:Imaging, Three-Dimensional / Q000379:methods; D008046:Lip / Q000473:pathology / Q000601:surgery*; D008875:Middle Aged; D017060:Patient Satisfaction; D010780:Photogrammetry / Q000379:methods; D019736:Prostheses and Implants; D015361:Rhytidoplasty / Q000009:adverse effects / Q000379:methods*; D015595:Skin Aging; D016896:Treatment Outcome
chemical_list: D001672:Biocompatible Materials; C502935:Perlane; C422414:Permacol; C048470:glutaraldehyde-cross-linked collagen; D006820:Hyaluronic Acid; D003094:Collagen