December 12, 1990
There is very little frictional resistance to sliding movement between this .015 coaxial archwire and the anterior brackets in this situation. The bicuspid brackets on the other hand, have a firm frictional grip upon the archwire preventing them from slipping distally during most of the 'swinging' rotational movement about to take place.
March 12, 1991
As observed in the band experiment 20 years before, each bicuspid has advanced much as the spoke of a locomotive drivewheel advances when it rolls along a rail. However, at this stage, the frictional forces associated with the archwire/bracket coupling have
diminished to near zero so that stretched transeptal fibers can now tow the bicuspids distally into the newly formed spaces if stops are not applied.
Treatment & Clinical Photography by: Dr. G. Herbert Hanson