- Midpoint of the sphenoid fossa (S): Move posterior and upward, fronto-nasal joint point (N): Move forward and upward along the Ba-N axis, anterior nasal spine point (Ans): Move out anterior and downward, chin point (Gn): Move down and anterior, center of mandibular vertical branch (Xi): Move back and down, center of neck of condyloid process (Dc): Move out back and up