Is photogrammetry of the face reliable?

The reliability of photogrammetry was assessed in 18 healthy young, white Canadians of each sex. Landmarks were indicated on the face before direct measurement and photography. Of 104 surface measurements taken directly from the head, face, and ears of subjects, 62 could be duplicated on the life-size frontal and left lateral photographs taken from the head in standard position. Of these 62 measurements, 26 were reliable (the same as or differing from the direct measurements by no more than 1 mm or 2 degrees). The greatest number of reliable measurements were of the lips and mouth (7 out of 13), but no ear measurements were reliable. Almost half (9) of the reliable measurements were inclinations. More correct vertical measurements were possible from lateral prints than from frontal views, but many lateral facial measurements from profile prints were distorted. Frontal-view prints gave additional reliable measurements.