Modifications from
the Basic Design
Several options are also available with this Twin Block appliance including the use of a sagittal or expansions design in the upper and/or lower arches.
     The appliances can be modified as the case requires and designs may be used in any combination. For example, upper and lower expansion screws may be used for lateral development, an upper sagittal type appliance may be used with a basic lower appliance, and a face bow, or reverse headgear, may be incorporated in
the case design. In addition to
these options, a fixed/removable
Twin Block and full banded versions can be made using a Wilson 3D type of appliance or a full banded style.

1. Class II correction (A-P)
2. Vertical development--to open
3. Vertical correction--to close
4. Arch expansion
5. Arch lengthening

How is the fit and retention?
 Dr. Gerber always clasps the first molars for increased  stabilization. He also prefers around acrylic edges for a more comfortable fit.

Adjustment for the Expansion
Screw
Lateral or arch length development may be achieved by instructing the patient to adjust the screws 1/4 turn each week. Expansion should be completed before banded block.

Laboratory Requirements
The laboratory requires upper and
lower stone models. A wax construction bite in a forward and open position is also required, usually 4 to 5 mm forward and 4 to 5 mm open in the bicuspid area.

Patient Participation
I require patients to chew stick free gum for two hours a day in order to close the bite with continuous force.

Dr. Jay Gerber operates his full time practice in
St. Marys, West Virginia. In 1980 he opened his
 Orthodontic Studies program where you will find
him lecturing on orthodontic, TMJ and neuro-
muscular advancements throughout the United
 States.
Dr. Gerber is an IAO Senior Instructor and was
 recognized as the "1990 clinician of the year"
by the AAFO.

For non-compliant patients, Dr. Gerber
 prescribes his "Banded Block" shown above.