Objective: Inclination of the anterior surface of the forehead from the vertical more than 2 SD above the mean
Subjective: Apparently excessive posterior sloping of the forehead in a lateral view
Measurement requires an angle meter, inclined on the anterior surface of the forehead, in the midline, along a line connecting the hairline to the glabella, compared to the vertical [Farkas, [1981]] with the head held in the Frankfurt horizontal.