They are called 'step-offs'.
Here is an illustration found on Spanish max fax doc's site (Alfaro) where he gets a good CCW and also maintain some 'drop' or good length to the back angle of the mandible in addition to a good forward advancement. The step off is seen in the computer simulated plan.
The lines on the illustration are drawn by me to show that one does NOT cut off the step offs in order to make the jaw line 'stream line'. If that were done, bone structure would be lost. Also bone paste is not used on a VACANT space which is the angled area between the part of the red line and the yellow line. INSTEAD, later on, a thick filler (Macrolane) can be use to fill the soft tissue above the yellow line. In that way, the whole jaw line will look EVEN.