Pitchfork analysis is given by:
Pitchfork analysis

The pitchfork analysis was developed by Johnston in 1985.
Growth and displacement of the maxilla and mandible are measured relative to the cranial base (SE).

The change in the position of the upper and lower molars and incisors are measured relative to the basal bone. All measurements are made parallel to a mean functional occlusal plane. The algebraic sum of various skeletal and dental changes is equal to the treatment change in the molar relationship and incisal overjet.
Pitchfork (1987)
Pitchfork (1986)
Johnston (1985)
Pancherz (1986)