title: Fractional CO2 laser resurfacing of photoaged facial and non-facial skin: histologic and clinical results and side effects.
abstract: BACKGROUND
  CO(2) fractional ablation offers the potential for facial and non-facial skin resurfacing with minimal downtime and rapid recovery.
  
  
  OBJECTIVE
  The purpose of this study was (i) to document the average depths and density of adnexal structures in non-lasered facial and non-facial body skin; (ii) to determine injury in ex vivo human thigh skin with varying fractional laser modes; and (iii) to evaluate the clinical safety and efficacy of treatments.
  
  
  METHODS
  Histologies were obtained from non-lasered facial and non-facial skin from 121 patients and from 14 samples of excised lasered thigh skin. Seventy-one patients were evaluated after varying energy (mJ) and density settings by superficial ablation, deeper penetration, and combined treatment.
  
  
  RESULTS
  Skin thickness and adnexal density in non-lasered skin exhibited variable ranges: epidermis (47-105 mum); papillary dermis (61-105 mum); reticular dermis (983-1986 mum); hair follicles (2-14/ HPF); sebaceous glands (2-23/HPF); sweat glands (2-7/HPF). Histological studies of samples from human thigh skin demonstrated that increased fluencies in the superficial, deep and combined mode resulted in predictable deeper levels of ablations and thermal injury. An increase in density settings results in total ablation of the epidermis. Clinical improvement of rhytids and pigmentations in facial and non-facial skin was proportional to increasing energy and density settings. Patient assessments and clinical gradings by the Wilcoxon's test of outcomes correlated with more aggressive settings.
  
  
  CONCLUSIONS
  Prior knowledge of normal skin depths and adnexal densities, as well as ex vivo skin laser-injury profiles at varying fluencies and densities, improve the safety and efficiency of fractional CO(2) for photorejuvenation of facial and non-facial skin.
authors: Sasaki Advanced Aesthetic Medical Center, Pasadena, California 91105, USA. ghsasakimd@drsasaki.com
authors: Gordon H
authors: GH
authors: Sasaki
authors: Heather M
authors: HM
authors: Travis
authors: Barbara
authors: B
authors: Tucker
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002245:Carbon Dioxide; D003357:Cosmetic Techniques / Q000295:instrumentation*; D005145:Face; D005260:Female; D006801:Humans; D054020:Lasers, Gas; D028022:Low-Level Light Therapy; D008297:Male; D008875:Middle Aged; D009333:Neck; D012060:Rejuvenation; D012867:Skin / Q000528:radiation effects*; D015595:Skin Aging / Q000528:radiation effects*; D013848:Thigh
chemical_list: D002245:Carbon Dioxide