Quad Helix Appliance
The definition of quad helix appliance is an orthodontic appliance that is used to gently and gradually widen a patient’s jaw. This type of device falls under the category of palatal expander. Because the quad helix expander is used on the upper teeth/jaw, it may also be called a maxillary expander. Maxillary is the term used when referring to the upper jaw. When referring to the lower jaw, the term mandibular would be used.
Habit Appliance
Habit appliances are devices that are most commonly used to help youngsters stop sucking their thumbs. Habit appliances are also known as habit breaking appliances or crib appliances. Most are metal devices that are placed on the inside of the front teeth and can look like metal retainers. Some habit breaking devices can be removed, like retainers, and some are glued into place and cannot be removed. Habit breaking appliances are often held in place by the upper molars. Habit breaking appliances can both physically stop the bad habit and can serve as a reminder to not partake in the bad habit.