Translation occurs when a force is applied through the center of resistance (CR) of a tooth. Translation is pure bodily movement with no rotational component.

Intrusion: Translation into bone

Extrusion: Translation out of bone

The fact that teeth are embedded in bone in the mouth makes sideways translation of a tooth difficult. What would you do if you wanted to translate a tooth to the right? To apply a force directly through the CR is impossible. You do not have direct access to CR, because it is within the bone.

Orthodontists have circumvented this problem by utilizing a counterbalancing couple (CBC) with a moment equal to and opposite in direction to the moment created by a single force acting on the tooth. CBC allows you to negate the rotational component of tipping and produce pure translation. Recall that translation using a CBC is one method of controlled tipping.