Who proposed the last tooth in each class is the least stable, except for mandibular incisors?

The concept that the last tooth in each class is the least stable, with the exception of the mandibular incisors, is attributed to Ballard. This principle highlights the importance of dental anchorage and stability in orthodontics, particularly in the context of tooth position and morphology.

In orthodontic treatment, the last tooth in each class, such as the last molar or canine, tends to be less stable due to its position in the dental arch and the type of occlusion it participates in. The mandibular incisors are an exception because they are centrally located and have a different functional role in occlusion and stability compared to the more distal teeth. Understanding the principles proposed by Ballard helps orthodontists make informed decisions regarding treatment planning and expectations for tooth movement and stability during and after orthodontic therapy. This knowledge is crucial when assessing case complexity and developing strategies for maintaining tooth positions over time.