Class 1 - Posterior Openbite
It is the objective of a good bite (Occlusion) that all teeth fit well with teeth in the opposite jaw. When they don’t, it can be a functional problem like a tongue getting in the way or a biological problem where the just won’t erupt (ankylosis).
A palatal crib is a removable appliance that rests within the upper and lower jaws. Loops prevent the tongue from resting between the teeth.
Over time, the bite settles and the teeth can chew normally.