Down’s cephalometric analysis of a patient reveals a high mandibular plane angle. Which of the following landmarks are used for the construction of the mandibular plane in this analysis?
Tweed and Ricketts- straight line tangent to the lower most border of the mandible.
Downs- line joining Gonion to menton.
Steiner- line joining Gonion to gnathion.
Bimler’s line- line joining menton to antegonial notch.

Ref: Radiographic cephalometry:Jacobson A
Go-Me
Go-Gn
Tangent to the lower most border of the mandible
Me-antegonial notch