ortho the international C.E. magazine of orthodontics

I 13ortho3_2012 C.E. article_ Bent Wire System I Mandibular displacement is associated with an increase in facial height (Sari, 2003, Chung, 2004). Net gain in the arch perimeter may be calculated accordingly with the expansion performed. Motoy- oshi and co-workers reported that 1 mm increase in archwidthresultsinanincreaseinarchperimeterof 0.37 mm (Motoyoshi, 2002). Akkaya and collabora- tors determined that arch perimeter gain through expansion could be predicted as 0.65 times the amount of the posterior expansion when treatment isperformedwithrapidmaxillaryexpansionand0.60 timestheamountofposteriorexpansionwhentreat- ment is performed with semi-rapid maxillary expan- sion (Akkaya, 1998). This is also supported by Adkins andco-workers,whodeterminedthatarchperimeter may increase 0.7 times the expansion produced at the premolars. Some authors (Hime, 1990; Housley, 2003) have reportedanexpectedrelapseintheamountofexpan- sion, which appears to be the result of that pressure deliveredbythecheeksonthemaxillaryarchandthe resistance to deformation of maxillary sutures and surrounding tissues to maxillary expansion. Nevertheless, maxillary and mandibular expan- sion rises up as one of the important phases of orthodontic treatment, producing arch perimeter increaseandavoidingextractionofteeth.Increasing numbers of multi-banded techniques using passive self-ligating brackets have become popular, but few addressthechallengesofadaptingthesofttissuesto this new dental position. Long-term retention is the recommended solution to stability. The aim of the current paper is to present a new methodtoproducemaxillaryandmandibularexpan- sion and, at the same time, to treat the soft-tissue dysfunction that may be responsible for treatment relapse (Ramirez-Yañez, 2005). Two example cases treated with the BWS Ortho- donticSystemdevelopedbyMyofunctionalResearch Co. (MRC) in Australia are presented to explain the proposed treatment. _The BWS Orthodontic System The BWS Orthodontic System discussed in this article is composed of two different appliances: the Trainer™ and the BWS. These two appliances combined may simultaneously produce arch devel- opment and treat poor myofunctional habits. The Trainer, a pre-fabricated functional appliance, has amply demonstrated an ability to relocate the man- dible(Usumez,2004)tocorrectimproperforcespro- Photos/Provided by Drs. German O. Ramirez-Yañez and Chris Farrell. Fig. 1 Fig. 2 Fig. 3