What type of tooth movement describes a stationary crown while the root moves?

The correct choice is reverse tipping, which is characterized by a specific type of tooth movement where the crown of the tooth remains relatively stationary while the root moves in the opposite direction. This movement is important in orthodontics for achieving specific alignment and positioning of the tooth in the dental arch.

In reverse tipping, when the crown is stationary, the root's shift can help correct the angulation of the tooth, balancing the forces applied during treatment. This type of movement can be particularly beneficial for adjusting the position of teeth that may be tilted or misaligned without causing excessive movement of the visible part of the tooth, which can sometimes lead to complications.

Other terms like controlled tipping and uncontrolled tipping refer to different mechanics where both the crown and root move together, or where there is less predictability in the movement, respectively. Translation involves the simultaneous and coordinated movement of both the crown and the root in a more uniform manner, which is distinct from the specific dynamics of reverse tipping. Understanding these differences is essential for applying the appropriate orthodontic treatment strategies effectively.