ABSTRACT
Although simple orthodontic procedures are carried out by general dental practitioners, the more complex orthodontic cases are treated by either specialist practitioners or the hospital orthodontic service. The appliances that are used may be simply divided into: (a) removable appliances – which are made of a plastic (acrylic) base with
various metal springs and clips and are worn for the majority of the day, but which may be removed for cleaning purposes; and
(b) fixed appliances – which involve the cementing of various brackets and bands to the teeth in such a way that they may not be removed on a day to day basis. In both cases, tooth movement is obtained by applying forces via wires
and springs, while the appliance as a whole is retained by other teeth. Occasionally, extra anchorage is required and extra-oral traction is supplied wearing headgear to which are attached wires and elastics protruding from the mouth.
