In what year was the Guidance theory presented?

Guidance theory was first presented in 1981 by Dr. William L. McDonald. This theory emphasizes the importance of the dentist's guidance in directing the dental developmental changes, particularly in orthodontics. McDonald introduced this concept to discuss how the application of specific forces on teeth could facilitate desired movements while also taking into account the bone and soft tissue responses. The theory provides a framework for understanding the complexities of orthodontic tooth movement, making it a foundational element in orthodontic treatment planning and implementation.

In the context of the other years mentioned, while various advancements and theories in orthodontics were developed in the following decades, the foundational aspect of Guidance theory is firmly rooted in the early 1980s.