Practitioners and the public are also more aware of the topic of root resorption - particularly with the increased prominence of continuous-force arch wire.
There are now better methods of researching root resorption, and this research offers the insight that almost all cases treated using fixed appliances display a degree of root resorption. Not just in terms of a shortening of the overall root length, but also on the root’s face.
A study comparing the impact that continuous and intermittent controlled orthodontic forces have on root resorption found that “buccally directed intermittent forces for 8 weeks produce significantly less total root resorption (P \0.05) than a similarly directed continuous force of the same magnitude and duration" (1).
Another study out of Japan concludes the same thing regarding the importance of intermittent forces. Their study involved eight hours of constant arch-wire forces followed by eight hours without. Their conclusion was that eight hour intermittent force efficiently recruits osteoclasts while causing minimal root resorption (2).
MRC’s appliances - The Trainer System™, The Myobrace System™ and the Bent Wire System™ use intermittent forces and therefore minimise root damage.