Myofunctional appliances in orthodontics are the appliances which take help from the Muscles to act on the desired treatment plan, as the name suggests the muscles are used to bring out desired function.

Myofunctional Appliance is defined as – ” A Removable or fixed appliance which favorably changes the soft tissue environment” – Frank, 1974

” A removable or fixed appliance which changes the position of mandible so as to transmit forces generated by the stretching of the muscle, fascial or periosteum through the acrylic and wirework to the dentition and the underlying skeletal structures” – Mills, 1991.

Classification of Myofunctional Appliances by Profit:

Tooth Borne Passive Appliances: Activator, Bionator, Herbst Appliance

Tooth Borne active appliances: Expansion Screws, Springs etc

Tissue Borne Passive appliance: Frankel regulator (It is the only passive tissue borne appliance)

Fixed functional appliances: Herbst appliances, MARS, Jasper Jumper

Removable functional appliances: Activator, Bionator, Frankel appliance

Removable Fixed Functional appliance or Semi Fixed appliance: Lip Bumper

Groups of Myofunctional appliances based on their functions:  

Classification of Myofunctional appliances by Tom Graber into groups when the appliances were removable.

Group 1 – Teeth Supported – Ex: Catlans appliance and inclined plane appliance, etc.

Group II – Teeth and Tissue Supported: Ex: Activator and Bionator, etc.

Group III – Vestibular positioned appliances with isolated support from tooth and tissue – Ex: Frankels appliance, lip bumpers, vestibular screen.

Classification of Myofunctional Appliances based on Force transmitted to Structures:

Group I (Appliances which Transmits muscle force to the teeth): Oral Screen, Inclined Plane

Group II (Appliances which Reposition the mandible): Activator, Bionator

Group III (Appliances which reposition the mandible by acting on the Vestibule): Frankel appliance, Vestibular Screen

Indications of Functional Appliances are depending on the type of Discrepancy – Skeletal or Dental.

Only Functional Appliances are used in certain conditions like:

  • Mild Skeletal discrepancy
  • No Dental Crowding
  • Proclined upper incisors

Functional Appliances + Fixed Appliances:

Used to improve anteroposterior relationship before starting the fixed appliance treatment.

  • Class II cases
  • Reduce need for orthognathic surgery
  • Reduce amount of a comprehensive fixed therapy needed later on

Interceptive treatment:

Functional appliance is used during growth phase to prevent permanent skeletal deformities from forming

To reduce the proclination of Upper Anterior teeth