Fig. 17 Fig. 19 Fig. 18 when various Class II mechanics are employed, be they appliances, elastics, and other. 6 Any orthodontic distal-izing force that is occlusal to the center of resistance on a molar will produce tipping (Fig. 17). The crown rotates to the distal more than the roots distalize. The more occlusal the applied force is, the more the molar will tip. Orthodontic practitioners understand the Class II forces you employ in your therapies. Molar crowns will upright over their respective roots. If you do not move the molar roots distal during your patient’s treat-ment, don’t be surprised several months post treatment that your perceived Class I molar finish, relapses to an end on end molar Class II. An asymmetric Class II case was presented. A stable bilateral Class I platform was achieved using a TAD palatal retained Horseshoe Jet appliance. Simply placing brackets, bands, and wires on a case will not correct an asymmetric platform (Fig. 18). Orthopedic advance-ment of the mandible will not be successful either. Advancing the mandible in a case that is Class II on one side and Class I on the other side will result in the Class II side becoming Class I, and the Class I side becoming Class III. Fig. 19 demonstrates the results achieved on the extreme Class II side (right). The vari-ous colored lines indicate the pretreatment position of the maxillary right-side teeth, cuspid on back relative to where they should end up post treatment (Fig. 19A). Post treatment the colored lines are coincident (Fig. 19B). The roots of the teeth from the cuspid on back Fig. 20 are distal to their respective crowns five years post treatment (Fig. 20). References 1. 3M Unitek™ Temporary Anchorage Device. www.3M.com 2. Cope, Jason B., DDS, PhD; Fig. 9-2 Ortho TADs – The Clini-cal Guide and Atlas. Dallas, TX: Underdog Media, LP 2007. 3. https://shop.dentsplysirona.com/enus/search.html?q=triad 4. www.dentalline.de/fileadmin/assets/documents/ pdf/Prospekte/PSM_BENEFIT_04-12.pdf (BENEPLATE and TADs) 5. www.inmanpower.com 6. www.jco-online.com/archive/2016/03/159/ 7. www.jco-online.com/archive/2018/04/196-the-horseshoe-jet-for-miniscrew-supported-molar-distalization/ 14 Spring 2020 JAOS
Journal of the American Orthodontic Society Spring 2020: Page 14
