Functional appliances are devices that modify the functional environment in the oral cavity by influencing and changing the surrounding hard tissue. Functional devices can be used to correct malocclusions including class II and class III malocclusions and asymmetrical bites. Functional appliances have advantages including the ability to enlarge the transverse width of arches to provide extra space and prevent crowding. They also cause less problems for patients in comparison to fixed appliances. Fixed appliances can cause problems such as TMJ disorders, decalcification and gingival proliferation.
Choosing the correct appliance is important for optimum treatment results. Removable appliances have an important but limited role, fixed appliances are usually the appliances of choice. Functional appliances can be helpful in difficult cases and don’t have an effect on facial growth.
Well aligned dental arches are an indication for functional appliances, other indications include posterior positioning of the mandible, non severe skeletal abnormalities and lingual tipping of mandibular incisors.
An example of a functional appliance is the twin block. The name of the device suggests the nature of the device, it is composed of a maxillary block and a mandibular block which fit together, they are a lot more comfortable than mono block appliances. These blocks fit together in a certain way that encourages the arches to grow into the correct biting position. When patients close their mouth they’re forced to push the mandible forward this teaches the mandible to close in the new position. The twin block is a fast method to correct receding jaws, overbite or excess overjet.
Another functional appliance used in orthodontics is called the activator which is also known as the mono block. It was originally designed to be worn at night, it is composed of a large piece of acrylic. It can be used to redirect teeth...