The most popular modification of the old Activator, the Bionator, has long enjoyed popularity in Europe. Today, in the United States and Canada, both the Bionator and a modification of its design, the Orthopedic Corrector, continue to gain acceptance as effective appliances for use in both mixed and permanent dentition. A Monoblock appliance, the Bionator usually incorporates a lateral adjustment screw lingual to the lower incisors. The Orthopedic Corrector, essentially identical in design to the Bionator, features the addition of two side screws; one is placed in each of the lower lingual posterior quadrants.
Both the Bionator and the Corrector can be constructed to open, to close, or to maintain the bite. Since the appliances work to retrain the muscles of mastication, they are very helpful in preventing relapse, and are particularly effective in the treatment of Class II cases.
For cases in which sufficient repositioning of the mandible would normally require treatment with two Bionators, the Orthopedic Corrector offers two advantages:
1. With the Bionator, the repositioning with the first appliance is actually accomplished in about three months; however, since the vertical development takes another six to nine months, the mandible must be held stationary until the entire case is ready for the second Bionator. With the Corrector, the side screws can be utilized immediately upon completion of the initial repositioning, without an intermediate waiting period.
2. Since the second Bionator is usually used primarily to further reposition the mandible, the utilization of the Corrector’s side screws often eliminates the need for a second appliance.
TO OPEN BITE:
FUNCTIONAL CAPABILITIES:
• Class II correction (growth and forward movement of mandible)
•Vertical development in mixed or permanent dentition
• Development of upper and lower arch width in mixed dentition.
•Minor tooth movement (with modifications)
WAX BITE CONSTRUCTION:
Bite is usually taken forward, in an end-to-end position (if patient is comfortable in that position) with 2-3 mm vertical opening between anteriors. If patient cannot tolerate the end-to-end position, bite can be taken in a less protruded position.
TO CLOSE BITE:
FUNCTIONAL CAPABILITIES:
•Class II correction (growth and forward movement of mandible)
•Closure of anterior open bite (most effective in mixed dentition)
•Development of upper and lower arch width in mixed dentition.
• Decrease of vertical in mixed dentition.
WAX BITE CONSTRUCTION:
Bite is usually taken forward in a Class I position (if comfortable for patient) with 2-3mm vertical opening between posterior teeth.
TO MAINTAIN BITE:
For the very difficult cases involving a deep dental bite with a long lower face and a steep mandibular bite plane, the Bionator to Maintain or the Corrector to Maintain may be especially useful.
Initially, the appliance is used to encourage forward growth or advancement of the mandible. Later, the appliance can be further utilized to open the bite by removing the posterior bite pads; or, by removing the anterior cap, it can close the bite.
FUNCTIONAL CAPABILITIES:
• Class II correction (growth and forward movement of mandible)
•Vertical development (with removal of posterior pads) Vertical closure (with removal of anterior overhang)
• Development of upper and lower arch width in mixed dentition
WAX BITE CONSTRUCTION:
Bite is usually taken forward, in an end-to-end position, with 2-3mm vertical opening between the anteriors.
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