List of orthodontic functional appliances

Upper and Lower Jaw Functional Expanders

Orthodontic functional appliances are devices used in orthodontics that harness the muscle action from speaking, eating, and swallowing to produce forces that can guide the growth of the jaw and dental arches, correct malocclusion (misaligned teeth), and improve the overall facial profile. These appliances are primarily used in growing children and adolescents to correct bite discrepancies by modifying the position and growth of the jaw. This article provides a list of commonly used orthodontic functional appliances, highlighting their purposes and mechanisms.

Types of Orthodontic Functional Appliances

Removable Appliances

• Activator Appliance - Designed to encourage the forward growth of the lower jaw by holding the mandible in a forward position. It is used to treat Class II malocclusion, commonly known as an overbite.
• Bionator - Similar to the activator, the bionator positions the lower jaw forward, promoting growth and correcting Class II malocclusions. It allows more freedom of movement and is often preferred for its comfort.
• Twin Block Appliance - Consists of two removable blocks that interlock at a forward angle, encouraging the lower jaw to close in a forward position, thus correcting Class II malocclusions.
• Frankel Appliance - Also known as the FR appliance, it is designed to provide freedom for natural growth of the jaw by holding back the muscles that restrict expansion. It treats various malocclusions by creating more space for the teeth and jaw to grow.

Fixed Appliances

• Herbst Appliance - A fixed appliance that encourages the forward growth of the lower jaw by connecting the upper and lower jaws with metal rods. It is often used when removable appliances are not effective or suitable.
• MARA (Mandibular Anterior Repositioning Appliance) - A fixed appliance that aims to correct Class II malocclusions by holding the lower jaw in a forward position relative to the upper jaw.
• Forsus Fatigue Resistant Device - A fixed appliance used to treat Class II malocclusions by applying continuous force to push the lower jaw forward and the upper molars backward.

Selection and Use

The selection of an orthodontic functional appliance depends on several factors, including the type and severity of malocclusion, the age and growth stage of the patient, and the patient's compliance and preference. Orthodontists assess these factors through clinical examination, dental and facial analysis, and radiographic images before recommending a suitable appliance.

Advantages and Disadvantages

Functional appliances can effectively correct certain malocclusions and improve facial aesthetics, especially in growing patients. However, their success largely depends on patient compliance, as many of these appliances are removable and require consistent wear. Additionally, some patients may experience discomfort, speech difficulties, and an adjustment period when first using these appliances.

Conclusion

Orthodontic functional appliances play a crucial role in the field of orthodontics, offering a non-surgical solution to guide jaw growth and improve malocclusions. While they offer significant benefits, the choice of appliance must be carefully considered by the orthodontist and patient to ensure the best outcome.