Rubber Coating Rapid Dental Orthodontic Appliances Plastic Tray Material

Orthodontic Expansion: It is well known that expansion of the dental arches can be produced by a variety of orthodontic treatments, including those that employee fixed appliances.

Orthopedic Expansion : Rapid maxillary expansion (RME) appliances are the best examples of true orthopedic expansion in that changes are produced primarily in the underlying skeletal structures rather than by the movement of teeth through alveolar bone.

Passive Expansion when the occlusion is shielded from the forces of the buccal and labial musculature, a widening of the dental arches often occurs. This expansion is not produced through the application of extrinsic biomechanical forces, but rather by intrinsic forces such as those produced by the tongue.

Example as passive expansion are the dimensional changes in the dental arches produced by such vestibular shield appliances as the FR-2 of Frankel.

1.Rapid Palatal Expansion Appliances e.g. : Haas appliance. 

2. Slow Palatal Expansion Appliances e.g. : Quad Helix ,NiTi expander etc.

3. Dentoalveolar expansion Appliances e.g. : Conventional fixed appliances .