In growing individuals the tendency is for the jaws to lengthen but narrow over time. In adults, this narrowing and crowding continues over an entire lifetime. Expansion or widening of the jaw is an effective treatment in certain growing patients with overly narrow or constricted jaws.
Expansion is most effective before puberty when the jaws are still moldable.
Upper jaw expansion works by opening the sutures of the upper jaw and allowing new bone to grow. Expansion of the lower jaw involves uprighting tipped lower teeth, since there is no lower suture to open. How To Use There is a key that is inserted into the appliance and turned as directed by the doctor. An arrow next to the keyhole indicates the direction of the turn. Some initial pressure or tightness for about 5 minutes should be expected.