An orthodontic appliance for treating a malocclusion such as a class 3 malocclusion is disclosed. The appliance comprises an outer wall and an inner wall, and a web extending between the inner and the outer walls. The inner and outer walls and the web define upper and lower channels within which the respective arches of a patient can be received. The inner and outer walls form a mounting arrangement for mounting the appliance on the upper and lower arches of the patient. The outer wall has an upper portion which is offset relative to the lower portion and the upper portion forms an outer spacing formation for holding the buccal mucosa away from the patient's upper arch so that it does not inhibit development of the upper arch. The appliance also includes a tongue elevator for lifting up the tongue to a height above the lower arch.
