Variability of facial photographs for use in treatment planning for orthodontics and orthognathic surgery.

Facial photographs are commonly used preoperatively for recording and analyzing skeletofacial and dentofacial deformities prior to orthodontics and/or orthognathic surgery. This study was undertaken to determine the reproducibility of facial photographs over time in any individual patient. Twenty subjects had full-facial frontal and lateral, frontal smile, and lip-to-tooth length (incisor show at rest) photographs taken on 5 different days over a 7- to 14-day period. A total of 18 linear and angular measurements were made on each set of photographs. Standard errors of the 18 measurements over time were generally moderate but varied widely, suggesting that facial photographs have the potential to provide reliable diagnostic information in some cases. In any individual patient, however, there were some variations within measurements that were clinically unacceptable. Measurements made from pictures of the smile were significantly less reliable than those taken at rest, and measurements of vertical head posture and lower lip length were found to be the least reliable. This study suggests that some measurements from facial photographs are generally reproducible over time, but significant individual variations do occur.