Which of the following describes "extrusion" in tooth movement?

Extrusion refers specifically to the downward movement of a tooth in the context of orthodontic treatment. This movement occurs when a tooth is being moved away from its bony socket, resulting in the apical region of the tooth moving downwards. This process often involves the application of forces that enable the tooth to come further out of the gum line, which can be beneficial in cases where a tooth is positioned too high in relation to the other teeth or to create space for other orthodontic procedures.

Understanding this definition is vital for recognizing how different types of tooth movement can affect overall dental alignment and occlusion. In orthodontics, distinguishing between various movements such as extrusion, intrusion, tipping, and bodily movement is essential for planning effective treatment strategies. This specific identification of extrusion being a downward movement clarifies its role in achieving desired outcomes in orthodontic practice.