title: 3D stereophotogrammetry quantitative lip analysis.
abstract: BACKGROUND
  Reduction in lip volume is a stigmata of the aging face. There are many lip augmentation techniques but very few studies analyzing how these techniques change the three-dimensional structure of the lips. Furthermore, there is no consensus about whether the lip position should be standardized to either the lips closed or parted. The aim of this study was first to obtain a three-dimensional quantitative analysis of the lips in adults and to look for sexual dimorphism and, second, to compare whether more consistent measurements of the oral region can be obtained with the mouth open compared with it closed.
  
  
  METHODS
  Seventy young Caucasian volunteers underwent lip dimension analysis using 3D stereophotogrammetry with lips parted and closed. Parameters measured for consistency of results were linear distances (e.g., mouth width, total lip height, upper lip height), surface distances (e.g., upper vermilion), areas (e.g., vermilion upper and lower lip, total vermilion), and volumes (upper and lower lip volume, total lip volume). Analysis also compared lip dimensions between male and female subjects.
  
  
  RESULTS
  Consistent and reproducible results were seen with the lips closed compared with lips apart. All lip parameters (distances, areas, and volumes) were larger in men than in women. The following measurements had significant differences between males and females: mouth width, upper lip height median, upper white lip height median, upper white lip height lateral, lower vermilion surface distance, and area of vermilion (p < 0.05).
  
  
  CONCLUSIONS
  We present a novel technique for aesthetic assessment of the lips that is objective and achieves consistency with the lips in the closed position. Males have greater lip dimensions compared with females.
authors.affiliation: Queen Victoria Hospital, NHS Foundation Trust, Holtye Road, East Grinstead, West Sussex, RH19 3DZ, UK. drasawyer@hotmail.com
authors.forename: Adam R
authors.initials: AR
authors.lastname: Sawyer
authors.forename: Marlene
authors.initials: M
authors.lastname: See
authors.forename: Charles
authors.initials: C
authors.lastname: Nduka
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008046:Lip / Q000033:anatomy & histology*; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D010780:Photogrammetry; D012727:Sex Characteristics; D055815:Young Adult