The so-called movable functional appliance is a corrective device attached to teeth or mucous membrane, which patients and doctors can take off or put on at will, so it is also called movable appliance. It consists of a base, a fixer and various springs. There are many kinds of movable appliances, such as ordinary movable appliances, functional appliances, ring appliances and so on. Movable orthosis includes: 1. Orthotics-For adults, orthodontics is another alternative to traditional braces. More and more orthodontists began to use various appliances to move their teeth. The calibrator works in the same way as the fixed appliance, but it has no wires and brackets. The calibrator is basically invisible. When eating, brushing and flossing can all be removed. 2. Movable gap holder-This device has the same function as the fixed gap holder. It consists of a plastic or steel bifurcation between an acrylic base fixed to the mandible and specific teeth, thus maintaining the gap between these teeth. Third, the mandibular positioning appliance-mandibular positioning appliance is also called splint. This appliance can be worn on the top or bottom of the mandible, which is helpful to train the mandible and make it close to a more suitable position. The appliance can be used to correct temporomandibular joint diseases (TMJ). Lip Bumper-This appliance is used to keep the lips or cheeks at a certain distance from the teeth. The muscles of the lips and cheeks can exert pressure on the teeth, and this cushion helps to eliminate this pressure. Maxillary dilator-Maxillary dilator is an instrument used to dilate the maxilla. It is a plastic plate fixed at the top of the mouth. The pressure exerted by the screw on the plate forces the joints in the maxilla to keep stretching longitudinally, thus enlarging the space of the maxilla. 6. Movable retainers-Movable retainers should be worn on the top of the mouth. This appliance prevents the teeth from moving to the previous position. Movable brackets can also be trimmed to prevent thumb sucking. Seven, headgear appliance-after wearing this appliance, the back of the head is surrounded by a belt and fixed on the metal line of the front or face arch. The headgear appliance slows down the growth of the maxilla, keeps the back teeth in the original position, and pulls back the front teeth. The above is the introduction of "movable orthosis". If you have any questions, you can also consult our related experts online, and our experts will give you detailed and professional answers. Recommended reading: Are there any side effects after orthodontics?