There are two opposite patterns of mandibular (lower jaw) development: clockwise (CW) rotation and counterclockwise (CCW) rotation. Each produces distinct skeletal structure and frontal jaw appearance.
Clockwise rotation characteristics
- open gonial angle
- long anterior lower facial height
- short ramus and short mandible body
- recessed chin
- weak, narrow, rounded looking jaw from the front (classic underdeveloped lower jaw)
Counterclockwise rotation characteristics
- closed gonial angle
- horizontal jaw development
- short anterior lower facial height
- square, angular, broad jaw shape
- long ramus height
Why CCW is not automatically ideal
The CCW pattern is often assumed to be the superior goal, but it brings specific downsides. Excessive CCW rotation reduces anterior lower face height and can enter short face syndrome (SFS) territory.