The 2x4 appliance is used to correct- Bluegrass Appliance.. anterior cross bites and restore anterior aesthetics in the mixed dentition stage

1. The 2x4 appliance is used to correct:

A. anterior cross bites and restore anterior aesthetics in the mixed dentition stage.***

2. Bluegrass Appliance for:

A. tongue thrust *** 

Also for (Thumb sucking habit breaking appliance)