Eyes wide open to avoid misleading diagnosis and treatment planning.

Introduction: The treatment of impacted and transposed teeth is a challenge for clinical practice. A precise assessment of the relative position of the transposed tooth could lessen the risks of adverse effects, such as root resorption and periodontal problems.

Description of the case: An 18-year-old patient went to the Orthodontic Department of the Federal University of Juiz de Fora, Brazil for a re-evaluation of the orthodontic treatment to which she had been receiving since the age of 12. Attempted traction of an impacted maxillary canine resulted in root resorption, marked mobility and alteration in the position of adjacent teeth as well as loss of alveolar bone in the anterior region of the maxilla. This tooth was not only partially transposed, but it also had ankylosis, external and internal tooth resorption, which indicated the need for tooth extraction. A change was made to the treatment plan, with the extraction of the canine, bone graft and mesial movement of the posterior teeth.

Results: All the spaces were closed at the end of treatment, with normal overbite and overjet. At the follow-up, the teeth position, the shape of dental arches, disocclusion guides and dental occlusion were preserved. The bone graft in the maxilla showed height and mineral density stability.

Conclusion: The presence of the maxillary permanent canines in the dental arch is important for both aesthetics and a functional occlusion. However, despite the importance of their maintenance in the arch, it is well advised that each case be analysed individually.