As reminder A Classification of Facial Wrinkles by Gottfried Lemperle

An increasing number of injectable filler materials for facial wrinkles and folds points to the need for objective measurements of their effectiveness. Patient satisfaction is the goal, but proof of the value of a particular product requires objective measurement.

A wrinkle assessment scale was developed as a simple tool for use by plastic surgeons, dermatologists, and aesthetic surgeons who want to assess the changes resulting from injecting filler materials in their patients. By correlating the grade of the wrinkle in the reference photographs with the wrinkle in a patient’s face, a classification of 0 to 5 is assigned. Reliability of the scale was assessed by “live” judgment of 76 wrinkles by nine observers.

The same rating was given to 92.7 percent of all wrinkles. In a second trial, photographs from 130 wrinkles were presented to eight observers who rated 89.4 percent of all wrinkles equally. A significant correlation of 87 percent was found between subjective ratings and objective wrinkle depth measured by profilometry on 40 silicone impressions.

Manufacturers, monitors of clinical trials, health authorities, and most important, patients will benefit from objective data on current and new injectable materials.
(PDF) A Classification of Facial Wrinkles. Available from: https://www.researchgate.net/publication/11643185_A_Classification_of_Facial_Wrinkles [accessed Dec 18 2018].