Correcting A Recessive Lower Jaw In A Growing Individual

There are many types of orthopedic (as opposed to orthodontic) appliances used when the lower jaw has not grown enough, resulting in skeletal and bite discrepancies.  fixed appliances include the Herbst, Jasper Vektor, and MARA (mandibular anterior repositioning appliance).  Removable appliances include the twin block, mono block, and bionator.  Orthopedic appliances try to get the lower jaw to grow in a forward direction, providing a better relationship with the upper jaw and improving the facial profile.  The bite relationship is also improved because the lower teeth move forward with the lower jaw.

Fixed appliances have the advantages of being attached to the teeth and are not removable, so compliance with appliance wear is not an issue.  The down side is that they are fairly bulky and can rub on the cheeks and gums, making them uncomfortable.  There is also a tendency for them to break, or, in the case of the Herbst appliance, come apart.  This can require extra trips to the orthodontist to have them repaired.  The other major issue is hygiene.  They can be difficult to clean around, increasing the potential for damage to the teeth and gums.

Removable appliances tend to be more comfortable to wear than fixed appliances.  Learning to talk while wearing them does take a little work, but can be mastered in most cases.  They can also be removed for eating, activities like sports, and oral hygiene.  Removable appliances require at least 20 hours of wear each day, so patient cooperation is essential for them to be effective.