What are Myofunctional Appliances?
These are prosthetic devices, can either be fixed or removable, that can provide favourable changes to the teeth and the soft tissue surrounding them.
The position of the lower jaw is changed using the different pressure exerted by the surrounding muscles through the components of the Myofunctional appliances, usually acrylic and wires to the bones.
These devices also make use of the natural force exerted by the oro-facial muscles on the teeth and the alveolar bone.
Types of Myofunctional Appliances
The three main classifications of Myofunctional appliances are:
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Based on Removable Myofunctional appliances
The removable Myofunctional appliances include the following:
- These appliances need teeth support, like Catlan’s appliance, inclined planes etc.
- These appliances can have either teeth or tissue support, like the activator, bionator etc.
- Vestibular Positioned appliances that get isolated support from either tissue or tooth, like the Frankel
- S appliances, lip bumpers, vestibular screen etc.
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Based on fixed Myofunctional Appliances
The appliances that fall under this type are:
- Removable Functionals, like the activator, Bionator etc.,
- Removable and Fixed, which are available as both fixed and removable types, like the Twin Block and Herbst
- Semi-Fixed, are appliances with some of its components that are fixed and the others detachable, like the Den Holtz and Bass Appliance.
- Fixed appliances, include Herbst, Jasper, Churro Jumper, Saif Springs etc.
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Hybrid Myofunctional Appliances
This type of appliances include:
- Classical Functional Appliances, like the Activator and the Frankel’s Appliance.
- Hybrid Appliances, like the propulsor, double oral screen, hybrid bionators, etc.,
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Classification based on profit
The different appliances found under this classification are:
- The passive myotonic appliances, like Activator and Bionator, which are borne on the teeth.
- The active-myodynamic appliances, like the Bimler’s appliance, elastic open activator and the Stockfish appliance, which are also borne on the teeth.
- Passive appliances borne on the tissues, like Oral scree, and lip bumpers.
- Active appliances borne on the tissues, like Frankel’s appliances
- FOMA or Functional Orthopedic Magnetic Appliances
Treatment using Myofunctional Appliances
The treatment principles to be administered are decided depending on the type of force that is exerted and they are:
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Force Application:
The force is applied on structures like the bones, teeth or tissue, which results in a change in the form and also adaptation in the function
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Force Elimination:
This will remove all the abnormal forces that are acting on these structures, allowing for optimal development where the function is restored which is followed by an adaptation in the form.
Result of using Myofunctional Appliances
These appliances can help bring about the following changes:
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Orthopaedic Changes:
The appliances can help in hampering the growth of the jaws and also helps change the direction of the jaws’ growth. They can also accelerate the growth in the condular or joint area. It can even remodel the glenoid fossa or cavity near a joint.
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Dento-Aveolar Changes:
The changes involved here are:
- Can affect changes in the sagittal, transverse and vertical directions.
- Inhibit the maxillary teeth to move downward or forward abnormally.
- Backward inclination of the upper incisors.
- Forward Inclination of the lower incisors.
- Intrusion of the lower labial segment.
- Levels the curve of spee and also the tipping of the occlusal plane.
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Muscular & Soft Tissue Changes
The changes seen here are:
- Improved toning of the muscles of the face and mouth.
- Improved lip performance and removes lip trap.
- Adaptive tongue activity is also removed
- The rest position of the mandible is lowered.
- The pressure of the soft tissue from the cheeks and lips are removed.
Authored By Dr Sanjay N - Orthodontics & Dentofacial Orthopaedics, Bangalore
