American Board of Orthodontics (ABO) Practice Exam

The safest maximum diameter of 2 mm for Temporary Anchorage Device (TAD) placement is typically found between the canine and the first premolar in the maxilla. This area is chosen because it tends to provide adequate bone density and stability for TAD placement while minimizing the risk of injuring adjacent roots or other anatomical structures.

The maxillary canine area is known for having sufficient attached gingiva and bone support which promotes osseointegration of the TAD. This positioning helps achieve reliable anchorage for orthodontic movements, which is crucial in treatments requiring temporary anchorage.

In contrast, other areas may pose higher risks due to factors like proximity to teeth roots, anatomical landmarks such as the maxillary sinus or adjacent vital structures, and varying bone quality. Hence, the area between the canine and the first premolar in the maxilla stands out as the safest and most effective choice for the placement of a TAD within the specified diameter.