American Board of Orthodontics (ABO) Practice Exam 2026 – All-in-One Resource to Master Your Orthodontics Certification!

The statement that primary canine root resorption failure is a direct cause of impacted upper canines is false. In the natural dental development process, primary canines typically resorb their roots to allow for the emergence of their permanent successors, the upper canines. If this resorption does not occur as expected, it can lead to a situation where the primary canines remain in place, potentially obstructing the path of the permanent canines. However, while this may be a contributing factor, it is not considered a direct cause of impaction on its own.

Impaction of the upper canines can arise from various factors, including the presence of any obstructing primary teeth, the positioning of adjacent teeth, and overall dental arch space. Therefore, while primary canine root resorption may influence canine eruption, it is not the sole or direct cause of canine impaction. Other developmental issues, anatomical variations, and environmental factors can play significant roles in this process.