E-ARCH
LATERAL EXPANSION (Fixed)
The E-Arch is a fixed appliance used for mild posterior expansion of molars a distance of 3-4 mm. Many doctors like this appliance because it is a self-expanding appliance. It consists of a .032 wire housed in a tube in the anterior, with a compressed Niti coil spring located on the wire between the solder joint and the mesial tube. The gradual decompression of the coil spring typically results in 3-4 millimeters of expansion.