Rapid maxillary expansion (abbreviated RME) is done by a fixed appliance designed to widen the upper jaw’s bony base. It was first introduced by Angell in 1877. However, he was not taken seriously as the mere possibility of expansion of the bony palate was disputed and the procedure was initially forgotten about for decades. It was re-discovered after 1945 as a result of the work of Haas, Timms and Derichsweiler and its indisputable place in orthodontics is now assured. The appliance is usually fixed with bands to the 1. molars and the 1. premolars and, more recently with acrylic splints encompassing the posterior teeth. The very rigid appliance is held in place by a expansion screw in the middle, which, over a period of 2-8 weeks makes it possible for the two halves of the upper jaw to be gradually pushed apart by up to10 millimeters. New bone is then allowed to grow in the middle, so the RME is perhaps the only truly orthopedic device in orthodontics. Normally, surgery would be the only way to achieve such skeletal effects.
Using a RME is very often the expedient thing to do, because many orthodontic patients have an upper jaw that is too narrow. The desired widening of the jaw with a RME is skeletal, as it actually works by allowing new bone to form, whereas a removable brace is just intended to achieve a slight outward tilting of the posterior teeth which will not remain stable. The RME has many healthy side-effects that are all based on improving breathing through the nose; fewer colds and sinus problems, improved aeration of the inner ear through the Eustachian tubes resulting in an improvement in ear symptoms, better sleep and less bed-wetting. The latter effect occurs due to a better oxygen saturation of the blood which is caused by improved breathing. There is no other orthodontic appliance that has such a holistic effect and provides such good value for money.
Against this background, it is completely incomprehensible that German orthodontists often prefer treatments with removable active plates, even for very narrow upper jaws, which usually end unsuccessfully.
Tip for parents: With If your child has a narrow upper jaw and lateral crossbite please only accept the RME, never the active plate – because the latter leads to the tilting of the posterior teeth without the formation of new jawbone. Moreover, treatment with active plates shows high failure rates and on top, it’s uneconomical.